The Ford Barn

Ol' Ron · 07-24-2010, 05:17 PM

Boring a Flathead depends on your age. 55 and under .060, fore 55 .125, over 7o .182. and if your like Rumble seat, who is older than dirt. .250. And it still runs cool, nice torque motor .

NealinCA · 07-24-2010, 05:30 PM

I bored mine .040 at 40.

Pete · 07-24-2010, 06:14 PM

Quote:

Originally Posted by Ol' Ron

Boring a Flathead depends on your age. 55 and under .060, fore 55 .125, over 7o .182. and if your like Rumble seat, who is older than dirt. .250. And it still runs cool, nice torque motor .

How about if you are older than Rumbleseat?? I'm older than salt and you know what the Spartans did with salt.
.250 is a practical first bore for a flathead.
It leaves room for one cleanup...The rest of the engine is usually shot
after that.
I pity all the people that build street flatheads these days..They will never experience the back slapping acceleration and the screech of air going down 4 48's at full throttle...They will never experience the rump rump idle of a 280 degree cam as you idle down the street at 30 mph.
They will never experience the sound of the engine turning 6000 as you bang the next gear...
I always wonder if there are any TRUE enthusiasts left out there like we were in the 50's when almost everyone drove their hot rods to work every day and had at least one stoplight race a day.
We drove to the drags every weekend and raced. No trailers or tow bars.
I guess I am preaching to an audience of one though.

craneygartz · 07-24-2010, 06:22 PM

I took this 8BA to 3 3/8 at 17 years of age in 1957. Why? The block came with free pistons that size!

John Oder

Ol' Ron · 07-24-2010, 08:03 PM

Pete, My first flathead was 3 3/8 X 3 3/4. bought the pistons from Von Eslers Speed shop in Chicago. Had the block bored in Ft Athinson Wi in 1950 by the Ford garage in town. When thwy saw the size of the pistons they refused to bore the block unless I paid in advance. 5 bucks a hole. I bought a used cam and lifters at the same time, don't remember which one. That was a while back. Two duces and milled stock heads. I'd like to build another.

Walt Dupont--Me. · 07-24-2010, 08:07 PM

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I built a 3-3/8x4-1/8 =296 when I was 17 that was 57yr's ago. 3 duces, almquest cam. In a 39 coupe. Use to drag race in Sanford Me. Walt

Pete · 07-24-2010, 08:26 PM

Quote:

Originally Posted by Ol' Ron

Pete, My first flathead was 3 3/8 X 3 3/4. bought the pistons from Von Eslers Speed shop in Chicago. Had the block bored in Ft Athinson Wi in 1950 by the Ford garage in town. When thwy saw the size of the pistons they refused to bore the block unless I paid in advance. 5 bucks a hole. I bought a used cam and lifters at the same time, don't remember which one. That was a while back. Two duces and milled stock heads. I'd like to build another.

I wish you had been around out here..I would have let you try out my 32 coupe....(Everyone else did)
If I took everything off it that would come, it weighed 2300 lb.
Turned 120 in 11.34.....That would have put a smile on your face.
That was a 315 ci, 4 carbs, H&C mag and 404 cam on 145 av gas.
Drove it to work every day.

JWL · 07-25-2010, 06:22 AM

Here we see examples of "the older I get the better I was" syndrone. Such BS is ok so long as you make unknowing viewers aware that there are few facts available within.

Al K. · 07-25-2010, 08:49 AM

It is nice to see the face of the person writing. Gives it that personal feeling. Al K.

ford1 · 07-25-2010, 10:16 AM

Hey Pete, been there, a flat head block was meant to be bored as far as you could, .187, no need to bore to anything else if you were going to street rod it, run mine 3/8 with a merc crank, 4:55 gears, 400 jr cam, solid lifters, adjustables were junk even back then, 2 afb jugs, noting could out run me for the first 100 yards, not even the olds rocket 88's, i could buy flatheads at the wrecking yard for $15 apiece, i still have one engine ready to build with all the pieces stored in my garage, maybe my grand son will like it, my sons all use the chevy v/8's, where did i go wrong?

Ol' Ron · 07-25-2010, 10:26 AM

This isn't BS, it's embellishment.

PeterC · 07-25-2010, 11:54 AM

[QUOTE=experience the back slapping acceleration and the screech of air going down 4 48's at full throttle...They will never experience the rump rump idle of a 280 degree cam as you idle down the street at 30 mph.
They will never experience the sound of the engine turning 6000 as you bang the next gear...
I always wonder if there are any TRUE enthusiasts left out there like we were in the 50's when almost everyone drove their hot rods to work every day and had at least one stoplight race a day.
We drove to the drags every weekend and raced. No trailers or tow bars.
I guess I am preaching to an audience of one though.[/QUOTE]

I'd like to think I drive my flatheads "enthusiastically" but with extreme horsepower I am respectful of my 39 trans and Columbia as the weak link! - based on your "back in the day" description - just curious how often you blew things up when you pushed like that!

Mick/mo · 07-25-2010, 11:56 AM

6000 rpm. ?

Dee · 07-25-2010, 01:11 PM

Here's a Lincoln V12 that's been bored to 3-1/16, not much room left. This engine is being installed with a 4 barrel carb set up. Seems the '42 blocks are the only ones cored large enough to do this. This ought to add some "gitty-up" to my '48 club coupe.

Pete · 07-25-2010, 01:26 PM

Quote:

Originally Posted by PeterC

I'd like to think I drive my flateheads "enthusiasticlly" but with extreme horsepower I am respectful of my 39 trans and Columbia as the weak link! - based on your "back in the day" description - just curious how often you blew things up when you pushed like that!

Not too often..I was well aware of the weakness of 25 tooth gears although they did last longer than the other sets because of less torque multiplication..At the drags I started in second so there was only one easy shift...I road raced with the 25's also and used 1st gear in the slow corners...Early racing antique sports cars developed my skill at double clutching crash box transmissions. (a la 1st gear in a 39 box)
As far as BS, I don't deal in BS...If I post it in public, you damn well better believe I have documentation to back it up.
Oh, one other thing, the timing slips I have were read off the Crocker clocks, the same ones they used at Bonneville in those days.
They used to bring them up for the 4th of July 2 day race every year.

Oh, and YES, 6000 rpm shift point....They would pull to 6200.
With nitro, 6500.

Ol' Ron · 07-25-2010, 02:55 PM

Pete, It would be nice to know Just what you did to a Flathead to get this type performance. I can't get anyway near it. But I've never run fuel.

Pete · 07-25-2010, 07:49 PM

Quote:

Originally Posted by Ol' Ron

Pete, It would be nice to know Just what you did to a Flathead to get this type performance. I can't get anyway near it. But I've never run fuel.

First off, the old saying "no substitute for cubic inches" really applies big time on flatheads...Compression makes them go and it is not possible to get it on small engines...On a 315 which is about minimum inches, it is possible to get 11 to 1 without much work..12 to 1 on all out efforts.
My last engine was 323 ci..The next one is going to be 345 ci...
By the way I do not believe in re-building a stock block into a multi port one by extensive welding. (flatfire) While I have done that and I applaud the efforts of people that do it, I just happen to like the standard basic configuration.
Any more we can't get gas good enough to run these engines on the street unless we use av gas. That's not too bad an option for ocassional use.
After that the ports were done with a flow bench at hand...I leave the finish that comes from a carbide burr on the intakes...NO polishing..I found almost the exact same results as JWL..After a certain valve lift taking the valve clear out did not help any...The exhausts are where a big help can be had by taking the time to go as big as possible all the way through...After botching a few you learn how far to go..I use homemade center port baffles..I use reversion dams at the ex. port exits..2 inch pipe
W type headers dumping into a baffled 4 inch outlet.
I use a .200 deep relief. 1.75 in. valves, 1.685 ex. valves. Titanium valves nowdays...Plain stainless in the old days.
I have used several cams over the years. All performed very well..
The 6355 made the most all out horsepower but was a slug on the street..
Too much overlap...That was the cam I was using when I turned 158 at Bonneville(alcohol)....In the 323 I used a #4 Offy grind...Similar to the 404A..I use intermediate support bearings on the cam..If I have a steel core I use it but not essential.
In the new 345 I will probably use the 505A...Jazzy Nelson had very good success with it...I drill the lifters to get them down to 33 grams.
In the old days I used Isky double valve springs shimmed to 90 on the seat..Nowdays I use Chev valve springs made by Renton Coil Spring Co. because they absolutely NEVER fail.
In the old days, I used Forgedtrue pistons..Nowdays I use Ross.
In the old days I used welded cranks because that was all that was available to poor people....Now I use billet cranks but I am still poor...
In the old days, I took a NEW set of rods, shot peened and reconditioned them before balancing...Nowdays I use H beam rods.
On all the street engines I used an Edelbrock 4 pot manifold with 4 bored out Stromberg 48's....I always used a H&C mag...I always used an aluminum flywheel and clutch cover...If there was room in the chassis I would use a front damper.
On 3 of my engines after 1965 I ran Hilborn's.(not on the street except for a quick run to the triple X)....For drag racing I think when I tried floatless 48's they made as much or more hp than the Hilborn's..I never did the dyno comparison... I ran the 48's at Bonneville..
I found the rod bearings lasted much better when I jacked the oil pressure up to 90 lb.
The new 345 is going to have a dry sump system.
All of these engines would turn 7000...When drag or street racing I usually shifted at 6000 to 6200..
In the old days I would not have given the time of day to anyone wanting this info but for the last 20 years I have been passing it out freely..So far no one has come back to me to say they have tried any of it other than the cams...Myself, JWL and you Ron all seem to be freely passing out what we know..It's free and I enjoy it....I made a good living in pro circle racing in the old days but it's all for fun now......
As you say Ron, KEEP EM' RUNNING.

Ol' Ron · 07-25-2010, 10:15 PM

I must say that's an impressive engine. As you know I built my own flow bench before I wrote my book, just for kicks, but it never gave CFM just Percentages.
Later I had the opportunity to use a professional unit. In an effort to gain impressive flow numbers I tried every possible modification to the ports to gain more flow. Big engines need more flow than a small one and 10-12:1 CR impedes flow.
I and many others have looked for the Holy Grail of Flathead power and I believe your the only one that's found it. Thanks for the summery of your engine, wish I could have seen it run.
Take care.]

Ol' Ron

Straightpipes · 07-25-2010, 10:23 PM

Quote:

Originally Posted by JWL

Here we see examples of "the older I get the better I was" syndrone. Such BS is ok so long as you make unknowing viewers aware that there are few facts available within.

Viewers be aware, You are in company of the best, was, is, will be.........
Ol Ron pointed me toward the smiley cam and I'm still smilin'

Pete · 07-25-2010, 10:25 PM

Quote:

Originally Posted by Ol' Ron

I must say that's an impressive engine. As you know I built my own flow bench before I wrote my book, just for kicks, but it never gave CFM just Percentages.
Later I had the opportunity to use a professional unit. In an effort to gain impressive flow numbers I tried every possible modification to the ports to gain more flow. Big engines need more flow than a small one and 10-12:1 CR impedes flow.
I and many others have looked for the Holy Grail of Flathead power and I believe your the only one that's found it. Thanks for the summery of your engine, wish I could have seen it run.
Take care.]

Ol' Ron

I wish you could have driven it.....You can if you want, drive the 345 when it gets done.

HotRodmicky · 07-26-2010, 01:09 AM

So far we built only one real big engine ( 304ci.)
BIG Ports and 1.6 valves etc

We buildind a second engine right know.Problem is i don`t know what to do better as number one runs sooooo well

I talked to Pete a few times and followed his advice and got a cam(big) from him.

The 304 only has a 3x2 with 97s but that engine hauls ass BIG time !!!
And runs cool!
It lives in a street driven `32 roadster

Michael

Ol' Ron · 07-26-2010, 08:50 AM

I was building a 296 for my self 3 3/8X 41/8, but sold it to a fellow This is in a 35PU and the acceleration is breath taking. Even surprised myself.

Mike B · 07-26-2010, 10:00 AM

Quote:

Originally Posted by Dee

Here's a Lincoln V12 that's been bored to 3-1/16, not much room left. This engine is being installed with a 4 barrel carb set up. Seems the '42 blocks are the only ones cored large enough to do this. This ought to add some "gitty-up" to my '48 club coupe.

My kitchen table isn't that clean!

Henry Floored · 07-26-2010, 06:10 PM

This thread is fascinating to me. In my opinion the "Holy Grail" of Flathead performance is to get the edge of the cyl as close to the edge of the intake port. Then using a pop- up piston to give the air charge a large chamber to flow into. So far that's my theory but I plan to put it in motion very soon. I would like to get the largest practical cyl bore dia with the largest intake valve I can get in there, and I'm gonna use pop-ups on the street in my coupe. Don't see why not.

Would love to know how you fellas are getting such large cubes. What bore and cyl wall thickness are you ending up with?

I want to emulate this situation in a Ford Flathead....

Henry Floored · 07-26-2010, 06:12 PM

Now I'm not talking about actually moving the valves. Rather changing the relationship of the intake port to the combustion chamber. The only practical way I can see is by going to a pop- up affair.

Pete · 07-26-2010, 06:27 PM

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"Would love to know how you fellas are getting such large cubes. What bore and cyl wall thickness are you ending up with?"

Bore = 3.405
Stroke = 4.750
Wall thickness = average .090

Henry Floored · 07-26-2010, 06:37 PM

Awsome Pete, Thanks! What cylinder block type do you find is most capable of handling those large bores? I have an 8BA that is bored to 3 7/16 but has 2 sleeves. It's someone else's project so I don't know everything about it yet.

Pete · 07-26-2010, 06:42 PM

Quote:

Originally Posted by Henry Floored

Awsome Pete, Thanks! What cylinder block type do you find is most capable of handling those large bores? I have an 8BA that is bored to 3 7/16 but has 2 sleeves. It's someone else's project so I don't know everything about it yet.

I use any late block..Sometimes I have to go through several to get one with walls uniform enough.(sonic test)

jdl · 07-26-2010, 07:37 PM

Pete, what is the minimum cyl wall thickness for a street engine and still run cool? I know there are variables. your opinion?

Pete · 07-26-2010, 08:43 PM

Quote:

Originally Posted by jdl

Pete, what is the minimum cyl wall thickness for a street engine and still run cool? I know there are variables. your opinion?

A street engine should run ice cold compared to a race engine...Relatively speaking. I try to have .090 walls to start with on a 3 3/8 +.030 bore.
I ran 315 ci engines on the street many times and never had cooling problems....The big thing is to have the block acid stripped so you have bare metal to start with in the water jackets...Rust and scale are great insulators. A radiator that is clean inside helps too.

Ol' Ron · 07-26-2010, 09:15 PM

Rumble seat (Paul Garagan) is running 3 7/16 in his latest rebuild. He drove out for the chili party from Denver to Vermont and while he was here we had a heat wave that set some records . The temp never got over 185 in either bank. He has .100" wall cylinder wall thickness.
The thickest blocks are 99A/T (38-41 Merc/truck) Had one put to 3 3/8+ .030" and still had .170" wall. This block also has the intake valve 1/4" closer to the bore.
Good luck, keep us informed

Tim Ayers · 07-26-2010, 09:53 PM

Pete & Ol' Ron:

Much love for you both. You know that and I've song your praises numerous times.

Pete: I can't help to think that your walk to school was also uphill both ways...

I think one of the biggest differences from back in the day and today is that you could purchase a complete balanced 4.25" stroker kit for $125.00. Today, one custom made piston goes for that.

Yes, I understand Smokey said, "Speed costs, how fast you want to go?" But the '50's are long gone.

Other issue is, back in the day, you were tripping over 99A blocks. Today, consider yourself blessed by the flathead gods if you find any good block on the first shot.

That being said, I do believe in going big or go home. If you are going to bore it .030", what's the point in IMHO.

See what I mean. And like Ol' Ron says: Keep 'um runnin'

HotRodmicky · 07-27-2010, 10:14 AM

Has anyone tried to build a "squared" engine?
I mean stroke is the same as the bore.....

I know the closest you get is 3 3/8 bore and 3 3/4 stroke.
But what if you destroke it alittle....
Then special pistons and small CCs ......

Has anyone tried that?
Michael

Tim Ayers · 07-27-2010, 10:18 AM

Quote:

Originally Posted by HotRodmicky

Has anyone tried to build a "squared" engine?
I mean stroke is the same as the bore.....

I know the closest you get is 3 3/8 bore and 3 3/4 stroke.
But what if you destroke it alittle....
Then special pistons and small CCs ......

Has anyone tried that?
Michael

I believe Ol' Ron sings praises about a square motor. Hopefully he'll chime in on this.

Also, Barney Navarro ran an undersqaure (seriously destroked to I think somewhere around 189+/- c.i.) motor while he was trying to perfect his supercharging experimentation on the lakes.

39cent · 07-27-2010, 10:53 AM

I experienced the acceleration of a 296 inch flathead driving my buddy,s duece roadster. We beat 56 4 bbl chevys, but when the '57 dual quads came out they could get us. With 25 tooth lincolns, and 354 rear gears, we had to do rolling starts. But that baby would go and we could stay with vettes in the mountains. Three 97's, potvin eliminator, H&C mag, Ansen built motor, it was hard to drive downtown. Of course in those days there were few muscle cars around. flatheads still held thier own. It had done 122 at el mirage by a previous owner. believe it or not.

Ol' Ron · 07-27-2010, 11:03 AM

I like the 258ci engine because the port valve area can feed this to a higher RPM. WITH POWER. Having run a number of Dyno ests on Flatheads, they all seem to fall off after 45-4800 RPM. Sure they'll turn 55-6000 but the torque is gone. Very long cams with hi lift, and you can push this up abit, But the ports are th limiting factor. That's why Kong Jackson and Dick landy built their 16 port blocks. In Landys case the engines were supercharged and produced over 500 hp.

Back in the real world we have to use what Henry gave us. Porting and reliving work well at hi RPM, but offer little in the way of performance in a street engine.
I have a 3 3/8X3 5/8 crank assy and if I can find it , I'll sell it Cheep. Tell us how it works.

Tim Ayers · 07-27-2010, 11:08 AM

"But that baby would go and we could stay with vettes in the mountains." 39 Cent

It was only a matter of time until the infamous beating a Vette story worked its way into this thread

HotRodmicky · 07-27-2010, 01:42 PM

Quote:

Originally Posted by Ol' Ron

I like the 258ci engine because the port valve area can feed this to a higher RPM. WITH POWER. Having run a number of Dyno ests on Flatheads, they all seem to fall off after 45-4800 RPM. Sure they'll turn 55-6000 but the torque is gone. Very long cams with hi lift, and you can push this up abit, But the ports are th limiting factor. That's why Kong Jackson and Dick landy built their 16 port blocks. In Landys case the engines were supercharged and produced over 500 hp.

Back in the real world we have to use what Henry gave us. Porting and reliving work well at hi RPM, but offer little in the way of performance in a street engine.
I have a 3 3/8X3 5/8 crank assy and if I can find it , I'll sell it Cheep. Tell us how it works.

Hi Ron,
if you find the 3 3/8X3 5/8 crank assy i want to buy it and will build an engine.
Promised!
So go to the barn and look if you can find it......please

Let me know
Michael

Ol' Ron · 07-27-2010, 08:45 PM

Well this is a conundrum, since I moved I haven't seen it. I know where the crank is, but the rods and pistons are a mystery. Give me something to do tomorrow.

Bassman/NZ · 07-27-2010, 09:08 PM

Looking at a square motor from the other perspective..... what stops it from being bored and sleeved square? Piston angle? Crankcase clearance?

Henry Floored · 07-27-2010, 10:00 PM

Quote:

Originally Posted by Ol' Ron

I like the 258ci engine because the port valve area can feed this to a higher RPM. WITH POWER. Having run a number of Dyno ests on Flatheads, they all seem to fall off after 45-4800 RPM. Sure they'll turn 55-6000 but the torque is gone. Very long cams with hi lift, and you can push this up abit, But the ports are th limiting factor. That's why Kong Jackson and Dick landy built their 16 port blocks. In Landys case the engines were supercharged and produced over 500 hp.

Back in the real world we have to use what Henry gave us. Porting and reliving work well at hi RPM, but offer little in the way of performance in a street engine.
I have a 3 3/8X3 5/8 crank assy and if I can find it , I'll sell it Cheep. Tell us how it works.

Ron, the statement you're making about the Flatheads falling off at 4500 rpm is the exact reason why I think there is an inherent "dam" in the performance arena of the Flathead Ford. As you know at low engine speeds the Flathead's intake port/transfer area can easily cope with flow requirements. As engine speeds rise the port I feel either works pretty well or can be made to work pretty well. It's just that it's flipped on it's back and directing that airflow smack dab into the wall created by the cyl head. I'm convinced that by raising the dome over the cylinder significantly one could then significantly raise power due to less of a "flow dam" effect. I don't think trying to get the charge to make an abrupt turn like a stock or hi compression head does is the way to go at hi engine speeds.

I'm absolutely aching to test this theory. I realize that some racers of the past have done this with great succes but I would like to see what this can do on a street engine. I am seriously thinking of 3 5/16" x 4 1/4" or maybe even a 3 3/8" bore if my block checks out.

HotRodmicky · 07-28-2010, 03:00 AM

Quote:

Originally Posted by Henry Floored

Ron, the statement you're making about the Flatheads falling off at 4500 rpm is the exact reason why I think there is an inherent "dam" in the performance arena of the Flathead Ford. As you know at low engine speeds the Flathead's intake port/transfer area can easily cope with flow requirements. As engine speeds rise the port I feel either works pretty well or can be made to work pretty well. It's just that it's flipped on it's back and directing that airflow smack dab into the wall created by the cyl head. I'm convinced that by raising the dome over the cylinder significantly one could then significantly raise power due to less of a "flow dam" effect. I don't think trying to get the charge to make an abrupt turn like a stock or hi compression head does is the way to go at hi engine speeds.

I'm absolutely aching to test this theory. I realize that some racers of the past have done this with great succes but I would like to see what this can do on a street engine. I am seriously thinking of 3 5/16" x 4 1/4" or maybe even a 3 3/8" bore if my block checks out.

If i would build another BIG engine i would go 4 3/8 x 3 5/16.
Scat makes a crank and rods and Ross the pistons.
makes 302ci.

I know there is alot of talk about these long strokes about siderocking
the piston , but there are so many other engines that have a way worse
stroke/rod length ratio that i think it will work fine!

Ol' Ron · 07-28-2010, 08:51 AM

The biggest problem with the long stroke is piston speed. As the valve opens it shouls reach max lift at about 70 degs after TDC. This is when the piston is reaching max speed. the valve begins to close at around 135 degs and the piston begins to slow down. At very high RPM's the piston runs away from the intake charge, effectively de-stroking the engine. I di believe a pop-up piston will breath better. There are a coupla things you can do to do this without spending allote of money. Using a 3 3/4 strole piston on a 4" crank, then recessing the piston .125 into the head. Now remove the lip created by the transfer area. This can give aprox 9:1 in a 276 engine. After you build a few dozen engines, you'll learn allote.
Good luck.
PS Just remember, ALL the power the engine makes has to come through those ports.

Ol' Ron · 07-28-2010, 09:13 AM

I've heard of engines punched out to 3 1/2 - 9/16. The cost and reliability of these along with a 4 1/2" crank?? I have a friend that runs a 342ci flathead at the drags, runs in the 10's. He admits he didn't think it would last as long as it has..

BrianCT · 07-28-2010, 10:27 AM

Quote:

Originally Posted by Ol' Ron

I like the 258ci engine because the port valve area can feed this to a higher RPM. WITH POWER. Having run a number of Dyno ests on Flatheads, they all seem to fall off after 45-4800 RPM. Sure they'll turn 55-6000 but the torque is gone. Very long cams with hi lift, and you can push this up abit, But the ports are th limiting factor. That's why Kong Jackson and Dick landy built their 16 port blocks. In Landys case the engines were supercharged and produced over 500 hp.

Back in the real world we have to use what Henry gave us. Porting and reliving work well at hi RPM, but offer little in the way of performance in a street engine.
I have a 3 3/8X3 5/8 crank assy and if I can find it , I'll sell it Cheep. Tell us how it works.

Ron, I agree the 258 is the way to go. Just go with a light car to get performance. We are never going to beat the modern motors.

Tim Ayers · 07-28-2010, 11:17 AM

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Quote:

Originally Posted by Henry Floored

Ron, the statement you're making about the Flatheads falling off at 4500 rpm is the exact reason why I think there is an inherent "dam" in the performance arena of the Flathead Ford. As you know at low engine speeds the Flathead's intake port/transfer area can easily cope with flow requirements. As engine speeds rise the port I feel either works pretty well or can be made to work pretty well. It's just that it's flipped on it's back and directing that airflow smack dab into the wall created by the cyl head. I'm convinced that by raising the dome over the cylinder significantly one could then significantly raise power due to less of a "flow dam" effect. I don't think trying to get the charge to make an abrupt turn like a stock or hi compression head does is the way to go at hi engine speeds.

I'm absolutely aching to test this theory. I realize that some racers of the past have done this with great succes but I would like to see what this can do on a street engine. I am seriously thinking of 3 5/16" x 4 1/4" or maybe even a 3 3/8" bore if my block checks out.

I'd be curious on this because if you look at a Model A head, that dome area can't be any more open and thusly the 4.5 or 5 (don't quote me on that) to 1 compression.

I'm really curious on what you have in mind to cope with the loss of compression if you open up that area in the head?

I also believe the flathead is a engine of compromises. You can certainly do a lot of tricks to it, but those trick come at a cost by impacting performance in other areas.

95% of the guys running a flathead in their car would be tickled pinked with a nice, stout (+/- 276 c.i.) street engine after compared to a stoker. These engines can still be built to stay together for many years for $5K or under.

Anything more in the realm of tricks that you can't do yourself, the costs start to multiply quickly.

Ol' Ron · 07-28-2010, 02:36 PM

This is the size of a stock port, not much to work with.

Tim Ayers · 07-28-2010, 06:41 PM

Quote:

Originally Posted by Ol' Ron

This is the size of a stock port, not much to work with.

'Ol Ron:

Thanks, great picture.

Henry Floored · 07-28-2010, 11:07 PM

Quote:

Originally Posted by Tim Ayers

I'd be curious on this because if you look at a Model A head, that dome area can't be any more open and thusly the 4.5 or 5 (don't quote me on that) to 1 compression.

I'm really curious on what you have in mind to cope with the loss of compression if you open up that area in the head?

I also believe the flathead is a engine of compromises. You can certainly do a lot of tricks to it, but those trick come at a cost by impacting performance in other areas.

95% of the guys running a flathead in their car would be tickled pinked with a nice, stout (+/- 276 c.i.) street engine after compared to a stoker. These engines can still be built to stay together for many years for $5K or under.

Anything more in the realm of tricks that you can't do yourself, the costs start to multiply quickly.

Tim the lost compression is gained back by using a very hi dome piston which tightly fills the raised combustion chamber.

Yes the Flathead Ford certainly has some compromises compared to later engines. For example the small diameter camshaft combined with equally small diameter lifters. Makes agressive cam grinds a little tough. Combine that with the lack of a rocker arm to multiply lift, that's a big compromise. But yet the lack of rocker arms is one of the reasons why Flatheads are so simple and endearing.

But compare the Flathead Ford to many other antique engines and quickly we see that our beloved Flatty's have performance written all over them. They are compact and light. They have good fuel distribution with all the intake ports grouped near the carb. They have a good oiling system with insert bearings on most of them.

As far as 95% of guys being happy with a standard built 276" I would love to say you're right, but unfortunately what I really see is a lot of beautiful early Ford bastardized with all sorts of goofy GM and Mopar powerplants. Do I think that a Flathead Ford could ever compete toe to toe with a scrub 350? Heck no, but for me I'd like to suprise a couple of those guys with what a Flathead Ford can do. I guess I'd like more than just a strong cruiser. I'd like a stoplight bandit, one that could at least give a lazy crate 350 a run for it's money. That might be fantasy, but the idea of it is really cool to me.

As far as a pop up engine goes, I don't think it's all that exotic. There are only two components that deviate from an average build and that's the pistons themselves and the cyl heads that compliment them. I'm certain those items could double the cost of my theoretical engine but I'm determined to try it at least once. This engine could be built in any bore/stroke configuration including stock 221 or 239. It's just the pistons and heads and the machine work to make it happen.

Ron has shown us an excellent cross section of a Flathead Ford intake port. It definately could use a better short turn radius and a little more cross section. But if you look at the flow path it seems Ford designed the bottom of the port as a ramp directing about 80% of the incoming flow right under the far edge of the intake valve and straight up into the transfer area. In my humble opinion the transfer area is the single biggest cork in the process. As the piston races down the cyl you'd think that it would just suck the charge right down with it, but actually I believe that in fact a column of air moving that fast just can't get turned that abruptly. It bangs into the cyl head, piles up and get's bounced around till finally heading down to fill the cyl. By moving the combustion chamber up and increasing it's volume that same column of air now has a space to flow to. Backpressure in that area is relieved and we should see a corresponding increase in volumetric efficiency.

A Flathead Ford has an inherant advantage over almost any ohv engine in that it does not need a fancy combustion chamber shape to swirl or rotate the intake charge when the piston comes up to suspend the fuel droplets. The Flathead's piston pounds the mixture from over the top of the cylinder to the valve chamber and when the mixture is lit it is pretty well mixed by all that natural movement. This gives a pretty efficient combustion process. Another advantage is the ability of a Flathead to swallow huge crankshaft strokes. A scrub 350 has less than a 3 1/2" stroke while a standard Ford has 3 3/4" and a Merc a full 4". Then there are all the stroker combos that can be had at a decent price like 4 1/8", 4 1/4" even 4 1/2" are all in the realm of real possibility. They are cost effective too. Those big levers can provide a lot of grunt. That's another Flathead advantage.

HotRodmicky · 07-29-2010, 12:56 AM

Quote:

Originally Posted by Henry Floored

Tim the lost compression is gained back by using a very hi dome piston which tightly fills the raised combustion chamber.

Yes the Flathead Ford certainly has some compromises compared to later engines. For example the small diameter camshaft combined with equally small diameter lifters. Makes agressive cam grinds a little tough. Combine that with the lack of a rocker arm to multiply lift, that's a big compromise. But yet the lack of rocker arms is one of the reasons why Flatheads are so simple and endearing.

But compare the Flathead Ford to many other antique engines and quickly we see that our beloved Flatty's have performance written all over them. They are compact and light. They have good fuel distribution with all the intake ports grouped near the carb. They have a good oiling system with insert bearings on most of them.

As far as 95% of guys being happy with a standard built 276" I would love to say you're right, but unfortunately what I really see is a lot of beautiful early Ford bastardized with all sorts of goofy GM and Mopar powerplants. Do I think that a Flathead Ford could ever compete toe to toe with a scrub 350? Heck no, but for me I'd like to suprise a couple of those guys with what a Flathead Ford can do. I guess I'd like more than just a strong cruiser. I'd like a stoplight bandit, one that could at least give a lazy crate 350 a run for it's money. That might be fantasy, but the idea of it is really cool to me.

As far as a pop up engine goes, I don't think it's all that exotic. There are only two components that deviate from an average build and that's the pistons themselves and the cyl heads that compliment them. I'm certain those items could double the cost of my theoretical engine but I'm determined to try it at least once. This engine could be built in any bore/stroke configuration including stock 221 or 239. It's just the pistons and heads and the machine work to make it happen.

Ron has shown us an excellent cross section of a Flathead Ford intake port. It definately could use a better short turn radius and a little more cross section. But if you look at the flow path it seems Ford designed the bottom of the port as a ramp directing about 80% of the incoming flow right under the far edge of the intake valve and straight up into the transfer area. In my humble opinion the transfer area is the single biggest cork in the process. As the piston races down the cyl you'd think that it would just suck the charge right down with it, but actually I believe that in fact a column of air moving that fast just can't get turned that abruptly. It bangs into the cyl head, piles up and get's bounced around till finally heading down to fill the cyl. By moving the combustion chamber up and increasing it's volume that same column of air now has a space to flow to. Backpressure in that area is relieved and we should see a corresponding increase in volumetric efficiency.

A Flathead Ford has an inherant advantage over almost any ohv engine in that it does not need a fancy combustion chamber shape to swirl or rotate the intake charge when the piston comes up to suspend the fuel droplets. The Flathead's piston pounds the mixture from over the top of the cylinder to the valve chamber and when the mixture is lit it is pretty well mixed by all that natural movement. This gives a pretty efficient combustion process. Another advantage is the ability of a Flathead to swallow huge crankshaft strokes. A scrub 350 has less than a 3 1/2" stroke while a standard Ford has 3 3/4" and a Merc a full 4". Then there are all the stroker combos that can be had at a decent price like 4 1/8", 4 1/4" even 4 1/2" are all in the realm of real possibility. They are cost effective too. Those big levers can provide a lot of grunt. That's another Flathead advantage.

I believe that haveing no rocker arms is a big advantage as you have
a very light valve train and can use single springs.

Then you can run wild cam profiles

People say you have to watch lifter bores with a Isky 404A , but who
has seen oval ones in real?

I`ll try a 404A in a 284ci next year and then we will see!

Pete · 07-29-2010, 01:29 AM

"For example the small diameter camshaft combined with equally small diameter lifters. Makes agressive cam grinds a little tough."

You really should gather more reliable information before making such statements...It has been shown in dynamic testing that the flathead Ford cam does NOT deflect enough when running to change the timing enough to record on a dyno..You can see absolutely NO deflection with a strobe while it is turning 7000 rpm on a test stand... It may be deflecting but you cannot see it...If you are familiar with strobe testing, you can easily see a deflection of .002...It is a commonly known fact that everything else in the engine will be worn out before the cam bearings....Deflection of the cam would show very early in worn cam bearings.
As far as lifter diameter goes, check the diameter of a Chevrolet V8 lifter and compare it to a flathead Ford lifter..Flat lifter Chevys will turn 8000.
Flathead Fords will turn that also on a test stand but guess which one will last longer due to much lighter valve train.
Plain old rocker arm engines such as the common V8 are a poor compromise as far as performance....They were built that way to sell many units and build CHEAP AS POSSIBLE.
In the past, desmodromic valve train was the hot thing as far as high performance went...F1 engines both in cars and motorcycles have always been on the leading edge of development and they both had that technology...When that became obsolete, electronic valve train was the new technology....No cam, NO ROCKER ARMS, no lifters, no push rods...Only valves.
GP engines nowdays turn 19000 rpm....they idle at 7000...
Rocker arms are Mickey Mouse as far as efficient technology goes.
Your mileage may vary.

HotRodmicky · 07-29-2010, 06:34 AM

Quote:

Originally Posted by Ol' Ron

The biggest problem with the long stroke is piston speed. As the valve opens it shouls reach max lift at about 70 degs after TDC. This is when the piston is reaching max speed. the valve begins to close at around 135 degs and the piston begins to slow down. At very high RPM's the piston runs away from the intake charge, effectively de-stroking the engine. I di believe a pop-up piston will breath better. There are a coupla things you can do to do this without spending allote of money. Using a 3 3/4 strole piston on a 4" crank, then recessing the piston .125 into the head. Now remove the lip created by the transfer area. This can give aprox 9:1 in a 276 engine. After you build a few dozen engines, you'll learn allote.
Good luck.
PS Just remember, ALL the power the engine makes has to come through those ports.

If you say "high RPMs" how high are we talking?

The 4 1/4 x 3 3/8 with the Potvin 425 won`t stop revving....
Have no tach but for a Flathead it revs high....

The 4 3/8 x 3 5/16 i would build as a torque motor anyway...
with a 404A for example....

That popup 276 sounds like a good Idea
Do build that often?
Which heads can take a 0.125 CC cut?

I know Sharp can but they are hard to come by....

Henry Floored · 07-29-2010, 06:47 AM

Pete, my statement about cam and lifter diameter is not about a deflection problem. It simply means it would be nice to start with a larger diameter blank with which to cut the more aggressive profiles. It simply would give the cam designer more to work with. As far as lifter diameter goes a little more footprint, while stock works 95% of the time, could be beneficial in not exposing the edge of the lifter to the camshaft lobe lifting ramp in the most radical racing cam designs.

Henry Floored · 07-29-2010, 07:03 AM

Quote:

Originally Posted by HotRodmicky

If you say "high RPMs" how high are we talking?

That popup 276 sounds like a good Idea
Do build that often?
Which heads can take a 0.125 CC cut?

I know Sharp can but they are hard to come by....

Two production heads that I know of. Navarro Hi- Domes and Baron Racing Equipment pop- up heads.

HotRodmicky · 07-29-2010, 07:54 AM

Quote:

Originally Posted by Henry Floored

Two production heads that I know of. Navarro Hi- Domes and Baron Racing Equipment pop- up heads.

I`m aware of both. But both are very expensive .
I thought more of a more common head.

I like Barons chamber design.

I`m not so sure about Navarros hi-dome piston.... i don`t see an advantage over Barons etc....

Michael

Tim Ayers · 07-29-2010, 08:28 AM

Quote:

Originally Posted by Henry Floored

Two production heads that I know of. Navarro Hi- Domes and Baron Racing Equipment pop- up heads.

Henry Floored:

Regarding the pop-up idea. I got it and I must have missed the piston/hi-dome head part of your idea/post.

When I looked into doing this, Arias was the only company making pop-ups for this application. They were $125 a piece + the $875 for Navarro hi-dome heads so you'd be into $1,875 before anything else.

I believe someone mentioned Ross is now also making pop-ups but I don't know for certain.

If you're going this far, you may want to atleast look into using some Scat H-beam rods @ $425 [cheapest H-beam rod-albeit off-shore *YUK* made] a set.

This is what I meant by entering into the exotic side of flathead engine building. A lot of guys balk at spending $250 for a set of pistons.

Some of these guys would have a heart attack if you told them the pistons for their engine was going to cost them $1K.

Once recovered, they'd then go into a hour long story about how they bought their first car for $10.00, fought too dang hard in Korea to let something like this happen and how spending $1K for a set of pistons would be a crying shame.

Also, when I said 95% of flathead guys would be happy with a 276 c.i., I meant the guys who actually keep a flathead in their old Ford.

I'm not even interested in old Ford with a small block anything in it.

To me, the parts just don't fit. But, as with most thigns in life, to each his own.

Ol' Ron · 07-29-2010, 09:57 AM

Well that's allot of information to follow. I don't have that much knowkedge in cam design, I'll leave that to Pete. I ran a 404 for a while ans switched to a 400jr which ran much better in our application. The last cam I used in a racing engine was an Errson D410, it replaced the 400jr. Over the years I tried many cams in a racing application. I was also more knowledgeable about intakes & exhaust, combustion chambers. Light weight crank assys and rear brake drums and wheels. over a period of 8 years we took a 258ci engine with 2 bl carb from 22 sec lap time to 16sec. HOW?? Well let's say we learned alott from our mistakes.

lucky · 07-29-2010, 10:29 AM

I was thinking Ron said use regular 3 3/4 stroke pistons with a 4" crank for the pop-up setup, that still leaves the cost of special heads?
Guess I won't be building one unless could find some heads within reason.
Had a friend in about 1960 with a '32 cpe had a 3 3/8 X 4 1/2 popup engine,.
Red Cornett Summerset Ky built that engine and welded Merc crank and he proly made the pistons, can't remember what brand aftermarket heads he used.
Sure ran though, faster than my chev powered '34 pickup.
This is great stuff, keep it going.
Seems like he wanted a block stamped with Z?
marvin

Tim Ayers · 07-29-2010, 10:37 AM

I believe, the "Z" blocks were one of the military versions with high levels of nickel in the mix.

Pete · 07-29-2010, 12:38 PM

"could be beneficial in not exposing the edge of the lifter to the camshaft lobe lifting ramp in the most radical racing cam designs. "

That doesn't happen in any cam I have ever seen...It may appear to but actually does not touch the edge...If it did the cam and lifter would be toast in a short time.
The reason for using a larger diameter cam blank in a flathhead is because at anything over .420 lift on a stock core you can't get the cam in the block..To get "more cam" you need to increase the lift along with the RATE OF LIFT...On the Isky 505A and several other manufacturer's cams with more lift they either run the cam in the block or bore the cam line and put inserts in.
It is possible to design a cam with a rate of lift so high that on a graph the accelleration curve would be a vertical line..This would require spring pressures so high in order to work that the system would fail mechanically.
Isky found that .011 per degree squared was the practical limit for the 505A...In order to get more it would require an inverted flank acceleration ramp..That is not practical with a radius lifter....Many modern roller lifter racing cams have inverted flanks but they require spring pressures that are hard to imagine....In some cases 800 lb on the seat..1200 open...The springs are 2 inches in diameter, have 3 coils and are made from 5/16 diameter wire.

HotRodmicky · 07-29-2010, 01:31 PM

Quote:

Originally Posted by Tim Ayers

Henry Floored:

Regarding the pop-up idea. I got it and I must have missed the piston/hi-dome head part of your idea/post.

When I looked into doing this, Arias was the only company making pop-ups for this application. They were $125 a piece + the $875 for Navarro hi-dome heads so you'd be into $1,875 before anything else.

I believe someone mentioned Ross is now also making pop-ups but I don't know for certain.

If you're going this far, you may want to atleast look into using some Scat H-beam rods @ $425 [cheapest H-beam rod-albeit off-shore *YUK* made] a set.

This is what I meant by entering into the exotic side of flathead engine building. A lot of guys balk at spending $250 for a set of pistons.

Some of these guys would have a heart attack if you told them the pistons for their engine was going to cost them $1K.

Once recovered, they'd then go into a hour long story about how they bought their first car for $10.00, fought too dang hard in Korea to let something like this happen and how spending $1K for a set of pistons would be a crying shame.

Also, when I said 95% of flathead guys would be happy with a 276 c.i., I meant the guys who actually keep a flathead in their old Ford.

I'm not even interested in old Ford with a small block anything in it.

To me, the parts just don't fit. But, as with most thigns in life, to each his own.

Tim,
i think it`s real fun to talk what to do with a Flathead to gain more horsepower etc.

Sure you can`t go wrong with a 276ci .It's a really good size, but
it would be boring if everybody build the same engine.

You are right with Hi-Dome Navarro and Arias pistion beeing WAY to
expensive to be used on the street engine , so Rons way is much better!!!

Michael

Ol' Ron · 07-29-2010, 02:23 PM

One modification you can make to a cylinder head is to increase the angle of the transfer area into the cylinder. I cut this back with a ball end mill. However it lowers compression and I don't think it helps a street engine.

Tim Ayers · 07-29-2010, 02:34 PM

Quote:

Originally Posted by HotRodmicky

Tim,
i think it`s real fun to talk what to do with a Flathead to gain more horsepower etc.

Sure you can`t go wrong with a 276ci .It's a really good size, but
it would be boring if everybody build the same engine.

You are right with Hi-Dome Navarro and Arias pistion beeing WAY to
expensive to be used on the street engine , so Rons way is much better!!!

Michael

Michael:

I absolutely agree. I'll talk hi-po flatheads with the best of them. Maybe someday I'll have a real trick one as well.

I'm still taking them one engine at a time.

I wish only the best to those who want to and can go big and go all out with the bells and whistles. God bless them and keep 'um flat.

Tony Martino · 07-29-2010, 04:39 PM

Just reading this post..... sort of like being in church! As an old time car guy (60) I love the enthusiasm and the interest. I have been driving my 31 with a stock, lowly old 49-53 Merc V8 as an almost daily driver for about 7 years and never even added a 2 carb set-up, but hearing you guys has sparked my interest! Thanks for the inspiration! GREAT THREAD

Vergil · 07-29-2010, 06:50 PM

Great post and information to think about. Below is a picture of an 8ba I cut to see what it looked like through the port.

Vergil

Henry Floored · 07-29-2010, 07:47 PM

Sponsored Links (Register now to hide all advertisements)

[QUOTE=Pete;52570]"could be beneficial in not exposing the edge of the lifter to the camshaft lobe lifting ramp in the most radical racing cam designs. "

That doesn't happen in any cam I have ever seen...It may appear to but actually does not touch the edge...If it did the cam and lifter would be toast in a short time.
The reason for using a larger diameter cam blank in a flathhead is because at anything over .420 lift on a stock core you can't get the cam in the block..To get "more cam" you need to increase the lift along with the RATE OF LIFT...On the Isky 505A and several other manufacturer's cams with more lift they either run the cam in the block or bore the cam line and put inserts in.
QUOTE]

Pete this paragraph illustrates exactly what I meant. In my original statement I was merely pointing out something I would change (cam diameter) if one could do a "clean sheet" redesign of a Flathead Ford. With nothing to help multiply valve lift the cam bears the whole burden. In a perfect world I think a larger dia cam would be nice. As far as the lifters I guess I retract my statement to a point. While the stock Flathead Ford lifters are certainly adequate they too could be enlarged so as to focus the cam lobe footprint more within the diameter of the lifter. If a tomato can could represent the lifter and your finger the cam lobe's point of contact we can easily visualize this. When the finger tip is in the very center it is easy to balance the can, just like when the lifter is riding on the heel of the lobe touching it in the center. Slide the finger tip past center and the can wants to tip more and more just like the lifter wants to as it rises against the camshaft lift lobe. The process is repeated in reverse down the back of the lobe. You start building taller camshaft lobes and that moves the range of contact much farther out near the lifter margin. That's taxing on the lifter. That's all that I'm talking about.

Ol' Ron · 07-29-2010, 10:13 PM

Vergils Photo shows the spark plug location right over the valve. I think the plug locatin should be in the transfer area, where a power tip plug could be used. Edmonds and Flatattack heads have better locations. Probably doesn't mean much,but every little bit helps.

Tim Ayers · 07-29-2010, 10:20 PM

Quote:

Originally Posted by Ol' Ron

Vergils Photo shows the spark plug location right over the valve. I think the plug locatin should be in the transfer area, where a power tip plug could be used. Edmonds and Flatattack heads have better locations. Probably doesn't mean much,but every little bit helps.

Didn't some of the Kong heads come without the spark plug hole drilled/tapped for this very reason?

Man, does anyone know what happened to Kong's patterns? I also thought he had Winfield's cam masters as well.

I also think M. Davidson's heads were patterned after Kong's with some improvement Mike thought were needed.

Somewhere there is a treasure trove of flathead goodness stash out there somewhere.

HotRodmicky · 07-30-2010, 12:27 AM

Quote:

Originally Posted by Ol' Ron

Vergils Photo shows the spark plug location right over the valve. I think the plug locatin should be in the transfer area, where a power tip plug could be used. Edmonds and Flatattack heads have better locations. Probably doesn't mean much,but every little bit helps.

Yeah Ron i agree on the spark plug location.

I wish Flatattak heads were a little cheaper and not down under...

HotRodmicky · 07-30-2010, 12:32 AM

Quote:

Originally Posted by Tim Ayers

Didn't some of the Kong heads come without the spark plug hole drilled/tapped for this very reason?

Man, does anyone know what happened to Kong's patterns? I also thought he had Winfield's cam masters as well.

I also think M. Davidson's heads were patterned after Kong's with some improvement Mike thought were needed.

Somewhere there is a treasure trove of flathead goodness stash out there somewhere.

Winfield cams??? They are only good for four bangers....

I follow Petes school of Flathead cams ...... Winfield are lame cams

Read Pete statements on the HAMB about cams.

BTW I love this thread!!!!!!!!!

HotRodmicky · 07-30-2010, 12:32 AM

Has anbody used Motor City Flathead heads and cams?

lucky · 08-01-2010, 12:21 PM

Ron

If I wanted to build a late engine using 4" Merc crank, would you recomend the pop-up piston?

If so [for street use] what pistons and rods would you recomend?

Also what heads would be required for this?

Thanks, marvin

Ol' Ron · 08-01-2010, 01:08 PM

No I don't think that running a pop-up piston would be of any advantage at the engine operating RPM. Also the higher CR may cause fuel and ignition problems. Build a tight combustion chamber, play with the transfer area. You might consider angle milling the heads. But all these mods have little affect at the normal cruising speeds of the engine.

joe plumber · 08-01-2010, 03:33 PM

I've got some ocean front property in Arizona ,from the front porch you can see the sea.For sale ,best offer .

Henry Floored · 08-02-2010, 05:29 AM

Are there any more nuggets we can pull from this subject? I have re- read everybody's post at least 3 times. Kinda like a movie you can watch over and over again. What do you think is the highest streetable and naturally aspirated horsepower per cubic inch that is possible from a Flathead Ford? What about the same question for race engines? Anybody have any dyno numbers they'd like to share?

Henry/Kokomo · 08-02-2010, 06:29 AM

Quote:

Originally Posted by Henry Floored

Are there any more nuggets we can pull from this subject? I have re- read everybody's post at least 3 times. Kinda like a movie you can watch over and over again. What do you think is the highest streetable and naturally aspirated horsepower per cubic inch that is possible from a Flathead Ford? What about the same question for race engines? Anybody have any dyno numbers they'd like to share?

John Lawson (JWL) has written a very informative book WITH dyno numbers and his observations. If you don't already have one, I'd recommend it along with the book by Ron Holleran (Ol' Ron). They both present interesting and quantifiable numbers combined with personal experience.

Henry Floored · 08-02-2010, 07:05 AM

Thanks Henry! I have Ol Ron's book (excellent)! Looking forward to obtaining JWL's.

craneygartz · 08-02-2010, 08:09 AM

Be nice of you folks to post some links to the mentioned books, or at the minimum, some contact info, or just where to get them. The sellers might be amazed at the increase in sales, assuming such are still in print.

The point being, for every post in this thread, 29 1/2 people have been interested enough to look at the thread as of today.

John Oder

JWL · 08-02-2010, 10:20 AM

Thanks for the fine words and interest in my book. I think Ol Ron has some of my books to sell or you can contact me.

Thanks Again,
JWL

Kahuna · 08-02-2010, 12:17 PM

"What do you think is the highest streetable and naturally aspirated horsepower per cubic inch that is possible from a Flathead Ford? What about the same question for race engines?"

This will generate some arguements, I'm sure, but for "streetable (very subjective), my educated guess, having seen 3 well built flatheads on a dyno, is that about 0.65 HP/CI average. Then there is the race flathead that Ken Kloth built, raced and set records with. It is about, not quite, 1.1 Hp/CI. Not really streetable, but was once or twice driven to the local cruise nites. Helpful?
Jim

John R · 08-02-2010, 02:47 PM

As I recall, Ken Kloth's engine had a number of interesting features. Has any of these been documented in any detail in magazine articles or elsewhere? Be nice to learn more.

Henry Floored · 08-02-2010, 03:07 PM

I'd love to hear from Kenny Kloth. That guy is amazing. He is to Flatheads what Karol Miller was to Y-blocks.

Bruce Lancaster · 08-02-2010, 03:55 PM

Kloth's was unusually small in displacement for highly developed flatheads. This raises interesting questions about the nature of gains with big engines...
A big flathead can run more transfer area without excess loss of compression, but ports are stuck with the same limits and probably become the overall control to peak power possible.
Torque band should run higher/fatter in a big engine, good on street or broad-range racing...
But...is it fair to assume that at high end, fundamental port limits are going to set peak HP at about the same on big and small engines??

Bassman/NZ · 08-02-2010, 05:13 PM

I think Bruce hit the nail on the head. Beyond that limit the only way to get an increase is forced induction.

uncle max · 08-02-2010, 05:37 PM

Quote:

Originally Posted by John R

As I recall, Ken Kloth's engine had a number of interesting features. Has any of these been documented in any detail in magazine articles or elsewhere? Be nice to learn more.

Kenny's a local boy... I once got a peek at the silicone patterns he made for his combustion chambers. He bought blank heads from Offenhauser and carved the chambers himself, when he was finished, they bore an uncanny resemblance to the old Model A Police heads and came in at an unbelievable 6 to 1 compression ratio. That Merc would fly.

Vergil · 08-02-2010, 05:39 PM

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Here are a few pictures of an 8ba I cut apart to see what it looks like'

This shows how the cylinder walls varies in thickness, it also shows a pit and how thin the wall is at the pit. This engine has been bored .080" over.

1

You have heard on milling your heads on an angle to tighten the combustion chamber up and to leave more area over the valves for lift. This shows the piston up against the head and still has the gap between the outer piston edge and the head, milling on an angle would help get rid of this.

Vergil

Henry/Kokomo · 08-02-2010, 06:11 PM

Really a 6:1 ratio ? I'm surprised the ratio isn't higher.

Ol' Ron · 08-02-2010, 10:17 PM

I talked to Ken back in o2 and he was convinced that the ports couldn't feed a bigger engine. All his efforts were in making the engine berate better. Not bad for a 26? cube engine. I found that de-stroker rods and pistons, now all I have to do is find the crank.

Kahuna · 08-03-2010, 12:59 AM

Re: the Kloth engine. Virtually all of the engine details have been published in one book or another. There are, however, three areas NOT discussed:
1) Port work
2) Cam timing details
3) Final head developement

At 267 cubic inches, I don't think the engine can really be considered small. Certainly smaller than what is currently available in "off the shelf" stroker assemblies, but not small. Further, whether the ports are a limiting factor or not, and I think they are, I have to believe any Flathead guy would be very happy with an output in the 280 HP + range, regardless of displacement. Keep in mind, this (Kloth engine) was one single carb (4 bbl), stock Merc crank, rods, etc. 6200 rpm shifts, 6000 rpm thru the traps. Yummy! makes me drool.

Jim

HotRodmicky · 08-03-2010, 04:51 AM

Quote:

Originally Posted by Ol' Ron

I talked to Ken back in o2 and he was convinced that the ports couldn't feed a bigger engine. All his efforts were in making the engine berate better. Not bad for a 26? cube engine. I found that de-stroker rods and pistons, now all I have to do is find the crank.

Hi Ron,
i`m still want the setup . Let me know when you find the crank
Michael

Bruce Lancaster · 08-03-2010, 09:38 AM

Well, 267 is still half a litre down from where people start saying "Hey, that's a big flathead!"
It's only a little bigger than a Merc on its third rebuild.
On the compression...you have comp ratio, and you have actual comp pressure.
If the size of the engine actually allows it to fill cylinders well, pressure will be higher than if it is gasping for air and there is less in there to squeeze. Remember cylinder filling and max comp pressure are at torque peak, and as engine revs past that peak to power peak filling is dropping away. It would be interesting to know what the torque curve looks like on a highly developed 6200 RPM small engine versus a big one pulling 296 through there.
Flatdog's 12 second '34 coupe, which I got to drive on a long roadtrip, was shifted no higher than 5200...4-71 blown 307.
Torque curve did not actually curve as far as I could tell...it was monstrously high at all road speeds.

John R · 08-03-2010, 10:20 AM

I had forgotten that Kloth had made his own combustion chambers. I also recall that he used larger diameter cam journal bores and roller lifters. As Kahuna implies, the real innovations are still secret.

Bruce Lancaster · 08-03-2010, 11:15 AM

I gather that most of the really serious racers make their own chambers. One of our local draggers used to run different brand heads left and right to annoy the peanut gallery...both had been welded flat and new chambers hand-carved to his supersecret recipe, so anything up there was irrelevant anyway.
Flatdog told me a bit about the superduper high-level telephone circuit with people like Kloth. No one would divulge anything substantial, especially the total shape of their chambers, but they would drop hints about flow experiments on something like effect of lowering the ceiling over the valves...if someone else was seeing similar trends, a few more hints would be exchanged. Very, very guarded. I am sure that if I had walked into Flatdog's garage unannounced when a chamber was exposed he would have had to kill me, even though I am nowhere near these high levels of scientific inquiry!

Ol' Ron · 08-03-2010, 02:29 PM

Ken also bored the cam tunnel for a higher lift cam.

Kahuna · 08-03-2010, 04:16 PM

As some of you may know, Ken's engine and speeds were protested. The engine was torn down and the inspectors (no competitors) got a chance to look it over. It passed with "flying colors". At the time, there was considerable discussion among the competitors that the heads were the "Magic Bullet" that made the engine so powerful. A second set of identical heads was loaned to another competitor to try- Result? NO improvement. Just goes to show that it's always in the combination, not one specific item.
Oh, to know more--
BTW, I think Don (Flatdog) was beginning to find some of the "secrets", just before he passed away. He mentioned to me that he was seriously considering returning to a normally asperated engine configuration. Maybe Bruce can/will comment on some of the "Kitty Litter" experiments that Don did?

Bruce Lancaster · 08-03-2010, 04:44 PM

He ran low-budget air flow studies using a monstrous vacuum cleaner and kitty litter shoveled into the airflow...really.
His engine that I was most familiar with was built as normally aspirated engine and was extensively flogged with different intakes, but stalled out in the 14's...car was 3,000 pounder. He skipped right on to his next step, the blower, on same engine. Times dropped repeatedly, sometimes by multiple tenths, as he jacked the pullet ratio, and car was soon running high 12's. Similar '34 streetrods with 350's were running in the 15's at one meet...
Engine went into a purchased altered after it twisted the '34 frame. This rig and new blower engine were under development at his untimely death.
He was a real scientist, postulatig theories and thoroughly testing them, analyzing problems from as many angles as he could find.

I got to drive the '34 home from the jalopy showdown to NJ...felt like a smooth, calm 400 inch musclecar, but it was faster...

Kahuna · 08-03-2010, 09:41 PM

Thanks Bruce. I had heard that those litter tests were pretty informative. So sad that he passed away. Good guy
Jim

Ol' Ron · 08-03-2010, 09:45 PM

I really miss Don, we had several discussions about porting and head design. He put me on the kitty litter and I tried that in several tests. Interesting results.

Mike B · 08-04-2010, 12:09 AM

One serious thread I have been following, nothing to add..I'm not even worthy
to make asuggestion or a comment...but I do have a question, how are you guys "cutting apart" a block, for view?

Mike B · 08-04-2010, 12:14 AM

PS...I've seen 3? refernces to "Kitty Litter"...anyone want to explain?

Karl Wolf · 08-04-2010, 01:11 AM

You shovel it into an airstream, and watch the air flow through plexiglass parts...
I think... Karl

Kahuna · 08-04-2010, 03:53 PM

Mike
Bruce explained it back a few posts. Essentially it is the process of flowing Kitty Litter thru intake ports with a plastic/plexiglass combustion chamber to see what actually occurs during intake flow. This concept is not really new, as others have tried it using different media. I think it's probably a good idea, but takes a bunch of work to accomplish. I'd love to see a video of it.
Jim

Vergil · 08-04-2010, 08:31 PM

Quote:

Originally Posted by Mike B

One serious thread I have been following, nothing to add..I'm not even worthy
to make asuggestion or a comment...but I do have a question, how are you guys "cutting apart" a block, for view?

I used a 4 1/2" hand grinder with a cutoff wheel to cut as deep as it would go then finished the cuts with a reciprocating saw. It wasn't as hard to do as I thought it was going to be, be sure to wear a dust mask.

Vergil

flatjack9 · 08-04-2010, 09:28 PM

I used a sawzall. Cast iron cuts pretty easily. But it's still slow work.

Ol' Ron · 08-04-2010, 09:39 PM

I used a skill saw with metal cutting blade and a saws all

Bruce Lancaster · 08-05-2010, 08:40 AM

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Flatdog said that he smashed junk blocks with a sledgehammer, then selected chunks and started cutting til he got a neat edge where he wanted it. Some of his port pictures have been published on the HAMB.

Henry Floored · 08-07-2010, 06:03 PM

I have flowed baby powder through Flathead intake ports. On the exhaust port outlets I simply started a Flathead without the exhaust manifolds on to get an idea of what the exhaust flow was doing at the outlet area. In both cases the visual is very telling. It's very easy to see that at both of these visible points the charge "wants" to go straight. In the intake port it is shooting straight towards the center of the cyl head dome and on the exhaust port outlet it is blasting straight towards the center of the engine just like Bruce said that Flatdog found. The idea of a very center angled or even slash cut out ext header pipe is probably the best way to carry the charge out of all 4 outer ext ports. Precisely what Flatdog was doing.

Henry Floored · 08-07-2010, 06:29 PM

A few more thoughts on the intake porting and their ability to feed the larger displacements in the Flathead Ford. Certainly it would be nice to have the option of bolting on larger ports like our OHV bretheren can easily do. Unfortunately that's not an option for us. Ron gave us an excellent vertical cross section of a Flathead intake port. The area that appears to be "pinched" is actually the ramp that directs the intake charge into the combustion chamber. With the water passages above and below it looks like quite a bottle neck. In my opinion though it's not as bad as it looks. When I port the intakes most of the material I remove is from the sidewalls of the intake ports. I like the design of the intake port and I don't think I can improve on the Ford engineer's ramp effect. If you think about it ohv engines like the sbc have ramps in them to direct flow as the port snakes around the pushrods. I think the best way to approach Flathead intake flow is to optimize flow through the port just like you would on an ohv engine. Forget about making the turn down the cyl for awhile. After finding the practical limits of what the intake port can actually flow I'd build an area over the piston that could accept about 125% of that number. I'm talking a healthy cyl head relief. This is the approach I'd like to try on my next engine. Step one is getting a block section with the intake ports and getting the fixture built. Might even be able to talk the local race engine builder into flowing it on his Superflow bench.

Ol' Ron · 08-07-2010, 07:02 PM

I built a flow bench for my book, years later I had the opportunity to use a professional unit. This became addictive. I spent days, weeks themn months trying to find the holy grail of flow. I ran flow test with valves, without valves. I ground into the water jackets and shaped ports with bondo. I wish you luck, I hope you find it. But5 I'll bet you a steak dinner I can get as much flow in 20 minutes than you can in an hour or two..
I use a power file to machine the top of the port to about .100" thick measured through the water jacket. Grind down the lip by the guide and blend that in. Next fill the low spot between the guide and the mouth of the port with JB weld. 20 -30 minutes. This includes a 1.6 valve and the bottom of the valve is part of the port and should be quite flat 15-20 degrees .040" seat. I could go on but you get the idea.

Ol' Ron · 08-07-2010, 07:04 PM

PS use a 52-3 block

Vergil · 08-07-2010, 08:49 PM

I will be the first to admit I am not very knowledgeable about porting but I will throw up a few pictures of what I done to the intake ports (these are on the cut up engine) on my engine during assembly. The valves are Manley ProFlo.

Vergil

Before

After

Difference

Ol' Ron · 08-07-2010, 10:20 PM

Now remove an 1/8" from the bottom of the valve too. Most of the Hump at the bottom is still there. This is a good street port& valve It will pass more than eniugh F/A to run a 276 with a long cam to 4500+ befor the power falls off.

Vergil · 08-07-2010, 10:36 PM

Ron I have the engine redline set at 5000 rpm using a Schneider cam and pulls strong, should have had this post thread before building the engine, good information.

Vergil

Henry Floored · 08-08-2010, 08:48 AM

Guys thank you so much for sharing your knowledge. I find this subject fascinating and a real release from all the bad news we hear on the news everyday. Thankyou!

HotRodmicky · 08-08-2010, 01:46 PM

Quote:

Originally Posted by Vergil

Ron I have the engine redline set at 5000 rpm using a Schneider cam and pulls strong, should have had this post thread before building the engine, good information.

Vergil

Hi Vergil,
which Schneider grind do you use?
Michael

Vergil · 08-08-2010, 01:54 PM

Quote:

Originally Posted by HotRodmicky

Hi Vergil,
which Schneider grind do you use?
Michael

Schneider 270-F
Lobe Seperation 112
Intake Camlift .365
Exhaust Camlift .365

Vergil

Lyndon · 08-09-2010, 03:02 PM

My LB ended up being 0.100 over to clean up some bad rust pits on some of the non-cracked cylinder walls.

Ol' Ron · 08-09-2010, 04:28 PM

The 270 Schnider cam is a nice cam, sounds good and pulls well over 2599. Displacement and compression make up for any low RPM losses. I like a hot cam in a street machine,if your looking for mileage buy a Preis.
Vergil, for a street engine you don't want a very thin valve and you don't really need all that flow for a street.

Vergil · 08-09-2010, 05:41 PM

Quote:

Originally Posted by Ol' Ron

The 270 Schnider cam is a nice cam, sounds good and pulls well over 2599. Displacement and compression make up for any low RPM losses. I like a hot cam in a street machine,if your looking for mileage buy a Preis.
Vergil, for a street engine you don't want a very thin valve and you don't really need all that flow for a street.

Thanks Ron, another note on the cam, I have advanced it a little, now the intake valve closes at 43° ABDC instead of 49°, thought it might bring the torque curve down just a little and so far I am happy with it but I didn't get to run it with the cam set straight up.

Vergil

Blownflatheaddeuce · 08-09-2010, 09:25 PM

Quote:

Originally Posted by Kahuna

Thanks Bruce. I had heard that those litter tests were pretty informative. So sad that he passed away. Good guy
Jim

So true....he was a super freindly guy who even spared time for a flatheader for the other side of the pond.

Was shocked at his untimely passing.

Great info in this thread, lets keep it going.

Im currently in the throes of another blown engine build so its great to read the info in this thread.

BFD

Tim Ayers · 08-10-2010, 05:22 AM

Quote:

Originally Posted by Ol' Ron

PS use a 52-3 block

Ron:

Curious why you suggest using a '52-'53 block? I thought I read somewhere the metal/material used in these blocks wasn't as good as previous blocks.

Is that yet just another flathead myth? If not, I'm glad I have a primo standard bore '53 block then.

Tim

Tim Ayers · 08-10-2010, 07:35 AM

Quote:

Originally Posted by HotRodmicky

Winfield cams??? They are only good for four bangers....

I follow Petes school of Flathead cams ...... Winfield are lame cams

Read Pete statements on the HAMB about cams.

BTW I love this thread!!!!!!!!!

Can't say I agree with you. Some of the fastest drag engines ran/run Winfield's SU-1A.

Just because a cam is "wild" doesn't mean it's good. Take some time to really think about the theory and timing of some of the cams that are out there.

Winfield was a genius and knew what he was doing.

Always remember this: Opinions about flathead cams can be like dirty socks. We all have them and some stink worse than others.

Ol' Ron · 08-10-2010, 11:44 AM

I like the late blocks because they don't have any hardened valve seats and you can do wonders with the valve pockets.

Yes Winfield was a genius, I think he was responsible for the nOVu 183 ci and 700 hp on 3 main bearings.All this in 1939. However if I were to go racing, I can't think of a Winfield cam I would use .

Tim Ayers · 08-10-2010, 11:53 AM

Ah, got it. So, for street, don't use this block for it would needs atleast exhaust seats. But for a block to modify the valve train & ports, it would be a good candidate.

Ol' Ron · 08-10-2010, 06:52 PM

Yes, the late 49 to early 51 blocks usually come with hardened seats in the exhaust and a 1.72 chevy valve can be used in the intake. Keep the 1.5 in the exhause. This is about max for a street engine. I would even undercut the valve and maybe use a 30 deg seat. Back in the 50's we used De Sota and Chrysler valves. Often wondered how well they worked.??

Henry Floored · 08-11-2010, 08:14 AM

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I think the center main bearing cap on those Novi V8's was water cooled. That's how they made that center main live I think. I wonder why that was a 3 main brg engine in the first place? Is it possible that even the mighty Novi has roots in the Flathead Ford? The OHC Riley V8 used in Argentinian road races was rooted in the Flathead Ford.

Tim Ayers · 08-11-2010, 09:14 AM

Quote:

Originally Posted by Henry Floored

I think the center main bearing cap on those Novi V8's was water cooled. That's how they made that center main live I think. I wonder why that was a 3 main brg engine in the first place? Is it possible that even the mighty Novi has roots in the Flathead Ford? The OHC Riley V8 used in Argentinian road races was rooted in the Flathead Ford.

Harry:

If you havent yet, I think you'd enjoy reading this book.
The Golden Age of the American Racing by Griffith Borgeson

It is an incredible look back at the racing technology and the men who engineered, built and raced this stuff from the 1900's until the late '30's.

According to Borgeson's research, one reason the Novi still only had 3 bearings is the level of the U.S.'s machining and casting skills were so poor when compared to Europes, these early pioneers made a lot of consessions were taking this into account.

It wasn't until after WWI did America start to be considered the leader in maching and casting techniques.

Also, you kind of get the impression a lot these guys were stuck in there ways. If 3 bearings on a hopped-up Model T engine held together, no reason it would work for the Novi. Also, if I remember correctly, Winfield was the main engineer for this motor. He was considered the King of the Model T & A.

Important to note as well, Bugati and Alfa-Romeo already had in production their own OHV 4 cly. hemis prior to WWI. European cars were the ones to beat.

I'm leaving a lot out, but the book is just incredible. I believe their is a picture of Miller hand filing the prop. for one of this superchargers.

Plus, the stories regarding what the drivers went through is simply awe inspiring.

Bruce Lancaster · 08-11-2010, 09:33 AM

The Novi shared at least its bellhousing flange pattern with Ford, not because of any engineering connection but because the engine was first used with elderly chassis parts from the 1935 Ford Millers, or so I have been told.
Engine swap, anyone??

Bruce Lancaster · 08-11-2010, 09:35 AM

Let's get away from Indianapolis and roll back to flatheads...we have some serious experts spilling beans here, and we don't want to get in the way!!
Maybe the best thread yet on the new Barn??

Tim Ayers · 08-11-2010, 09:57 AM

Leaving it to the educator to get the kids back into line...

Tim Ayers · 08-11-2010, 10:04 AM

OK, let's get back to it.

Ol' Ron: You have tried hogging out the end exhaust ports (I know others as well) and made inserts to go in there place.

Did you ever get to flow test these designs? Did removing that much of the casting weaken the block at all?

Kahuna · 08-11-2010, 10:43 AM

There has always been great discussion/arguement re the exhaust ports on a flathead. Are they restrictive? Do center dividers work? Etc. Here's my opinion: On End Exhaust Ports, the best fix is to relocate them to the very end of the block to straighten the path (a lot of work, welding, etc). The Center Ports, while not being restrictive in a mild engine, can be improved greatly with dividers. The trick is getting the right dividers in the right place. Once this is done, one of the center ports will actually draw a vacuum on the adjacent one, kinda like a header does. This means that an engine with anything more than a stock cam (overlap) will benefit. The bigger the cam, the bigger the benefit. Will it be a noticeable improvement? Doubt it, but it's another peice of the combination that is so important to the overall engine effort.

Tim Ayers · 08-11-2010, 10:59 AM

Quote:

Originally Posted by Kahuna

There has always been great discussion/arguement re the exhaust ports on a flathead. Are they restrictive? Do center dividers work? Etc. Here's my opinion: On End Exhaust Ports, the best fix is to relocate them to the very end of the block to straighten the path (a lot of work, welding, etc). The Center Ports, while not being restrictive in a mild engine, can be improved greatly with dividers. The trick is getting the right dividers in the right place. Once this is done, one of the center ports will actually draw a vacuum on the adjacent one, kinda like a header does. This means that an engine with anything more than a stock cam (overlap) will benefit. The bigger the cam, the bigger the benefit. Will it be a noticeable improvement? Doubt it, but it's another peice of the combination that is so important to the overall engine effort.

Kahuna:

Great explanation and I agree about little things all being part of the bigger equation.

Would you happen to have any pictures? I know a lot of guys make center dividers out of sheet steel since the cast ones need to be whittled down so much to be of any use.

Kahuna · 08-11-2010, 11:18 AM

I'm sorry Tim, I don't. It's very difficult to explain. Look up 36tird on the Hamb and find his post on exhaust dividers. He's got a picture there that might be of help.
Jim

Kahuna · 08-11-2010, 11:18 AM

S/B 36tbird. Sorry, not enough coffee yet

Tim Ayers · 08-11-2010, 11:35 AM

Quote:

Originally Posted by Kahuna

S/B 36tbird. Sorry, not enough coffee yet

Cool, will do. I know exactly what you are talking about. Just like to see all of the different ways of tackling the issue.

Bruce Lancaster · 08-11-2010, 11:51 AM

We have at least two schools of thought to look over:
Ron's book (MANDATORY READING) details his efforts to straighten that last bit of exhaust tunnel by shifting the end ports toward the ends of the block.
Flatdog ended up going with the stock routing, and drastically slanted the front and rear of each port to match the tunnel, slanted toward center of block, with headers made to follow that path before turning.
Both obviously require fully custom headers built for the individual engine.
Vergel posted excellent cutaway pictures of the exhaust system on the HAMB recently, showing the path to be more smoothly curved than seems possible from external observation.
It seems to me that the high level of power increase flatheads can show with a big blower exonerate the design of the exhaust passages...if they are the engine's choke point, big increases driven by the intake side would not be possible. The engine would simply choke on its own exhaust.
Ever see the heads from a highly developed high-pressure turbocharged SBC??
Exhaust valves are offset and increased in size to the absolute limit and X ports are hogged out almost beyond belief to allow the engine to accept really radical increases on the intake side.

Tim Ayers · 08-11-2010, 11:59 AM

Quote:

Originally Posted by Bruce Lancaster

We have at least two schools of thought to look over:
Ron's book (MANDATORY READING) details his efforts to straighten that last bit of exhaust tunnel by shifting the end ports toward the ends of the block.
Flatdog ended up going with the stock routing, and drastically slanted the front and rear of each port to match the tunnel, slanted toward center of block, with headers made to follow that path before turning.
Both obviously require fully custom headers built for the individual engine.
Vergel posted excellent cutaway pictures of the exhaust system on the HAMB recently, showing the path to be more smoothly curved than seems possible from external observation.
It seems to me that the high level of power increase flatheads can show with a big blower exonerate the design of the exhaust passages...if they are the engine's choke point, big increases driven by the intake side would not be possible. The engine would simply choke on its own exhaust.
Ever see the heads from a highly developed high-pressure turbocharged SBC??
Exhaust valves are offset and increased in size to the absolute limit and X ports are hogged out almost beyond belief to allow the engine to accept really radical increases on the intake side.

Bruce:

I am currently doing it like Flatdog minus custom built headers. Maybe later on down the road.

I've ground a heck of a lot out of material out of those end ports to the point I'm worried how thin it got after taking out the "hump" casting flash & wire and what ever other crud was lurking around in there. I had to also open up the exhaust flanges on the my headers to extreme as well.

When I run my fingers in there it seems like it is certainly a much better path.

I am concerned that I may have increased the possible volume too much and therefore reduce the amount of back pressure. Not sure if this is even a problem, but I'm sticking with top of line 1.5 SBC hi-flow valves for both I & E and a Potvin 3/8ths cam (well- Potvin for know- On deck are also Clay Smith 272-2 & 284-2 cams, Crane 352-2 and/or Melling A-400 short track full race if the 3/8ths doesn't work out.)

I'm hoping the duration/overlap of all these cams (except the Crane which has more duration and lift on the exhaust side) will also help get some of that bad stuff out of those ports when needed.

Vergil · 08-11-2010, 01:02 PM

Here is one picture of the rear exhaust port. The block is not as thick as it looks in the picture because the cut was made close to the roof of the port. If wanted I can cut in the middle of the port to get an idea of the wall thickness. I still have the piece of block laying around here.

Vergil

Tim Ayers · 08-11-2010, 01:08 PM

Quote:

Originally Posted by Vergil

Here is one picture of the rear exhaust port. The block is not as thick as it looks in the picture because the cut was made close to the roof of the port. If wanted I can cut in the middle of the port to get an idea of the wall thickness. I still have the piece of block laying around here.

Vergil

Vergil:

Thanks. I had this picture right along side my Mike Bishop porting article and my calipers to get an idea of how much more I can grind away. Just look at that dog leg jambing up an already crowded port.

I was amazed at how much casting wire was still in both sides of my end exhaust ports.

If you have the time and are willing to cut open a center exhaust port, I'd for one would love to see it. I have a feeling I may have gotten a little carried away with my grinder in these as well.

If I can get off my lazy behind, I'll try to snap some pictures of the porting on the block vs. a stock block.

Don't count on it, things seem to have a way of not getting done at my house.

Vergil · 08-11-2010, 01:30 PM

Quote:

Originally Posted by Tim Ayers

Vergil:

If you have the time and are willing to cut open a center exhaust port, I'd for one would love to see it. I have a feeling I may have gotten a little carried away with my grinder in these as well.

Tim I have a few pictures of the center port I will load and share, at the time I cut the block and took the pictures I didn't get any good ones of the center port but I may see what the old block looks like and maybe get better pictures.

Vergil

Ol' Ron · 08-11-2010, 01:44 PM

I did some Flow work on the modified port in my book and saw very little improvement over just shaping it similar to Mike Bishops work. I square up the side of the port nearest to the block eng leaving aprox. 1/4" gasket surface. What surprised me was how well the exhaust flowed in comparison to the intake. Well within the 80%.

Tim Ayers · 08-11-2010, 01:54 PM

Quote:

Originally Posted by Vergil

Tim I have a few pictures of the center port I will load and share, at the time I cut the block and took the pictures I didn't get any good ones of the center port but I may see what the old block looks like and maybe get better pictures.

Vergil

Vergil:

You are the man! Thanks.

Tim

Vergil · 08-11-2010, 02:14 PM

Quote:

Originally Posted by Ol' Ron

I did some Flow work on the modified port in my book and saw very little improvement over just shaping it similar to Mike Bishops work. I square up the side of the port nearest to the block eng leaving aprox. 1/4" gasket surface. What surprised me was how well the exhaust flowed in comparison to the intake. Well within the 80%.

Ron that surprises me on the modified exhaust port shown in your book, I thought for sure it would show better flow than the results, good information.

Tim these are the pictures I have, the first ones shows where the cut was and if you need the floor of the port thickness I can get that for you. The machining on the intake ports shown in the picture was an idea for a fuel injection setup that didn't happen.

Vergil

hotcoupe · 08-11-2010, 02:17 PM

tim ayers, i hope this is the view your`e looking for.
tom
vergil is not only good, he`s FAST.

Vergil · 08-11-2010, 02:20 PM

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Quote:

Originally Posted by hotcoupe

tim ayers, i hope this is the view your`e looking for.
tom

Much better picture Tom, thanks and will now add it to my pictures.

Vergil

Tim Ayers · 08-11-2010, 04:14 PM

Hot Coupe & Vergil:

Thank you very much. I better step away from the grinder before I hit water. I didn't think it was that thin there.

As 'Ol Ron and cam grinder Pete say, "You got to build a few to learn a lot." (or something like that)

Kahuna · 08-11-2010, 08:06 PM

I fully agree with Bruce, Ol Ron and others that the exhaust ports are not the problem some folks have professed. I was quite suprised at the smoothness of the internal exhaust passages from the factory. Henry did a good job, except at the end port exit; but that area can be filled either with a metal insert, or better, with a high-temp moldable material. Then ground, smoothed, etc. Tim, don't worry about the back pressure. You don't want any and anyone who tells you otherwise is blowing smoke.
Jim

Ol' Ron · 08-12-2010, 09:06 AM

Thanks Virgil and tom for your pictures. I've never seen this much detail of the castings. In my book I moved the end exhaust to eliminate the exit bend, and was disappointed in the results. Some builders have suggested that because the exhaust is expelled under pressure the flow bench isn't the right tool to measure the difference. I will find some pictures of the ports I use in my street engines not sure how well they work either. The older I get the less I know.

Ol' Ron · 08-12-2010, 07:36 PM

I can email a photo of the port to someone that can post it. My email add is ron [email protected]

Vergil · 08-12-2010, 07:47 PM

Quote:

Originally Posted by Ol' Ron

I can email a photo of the port to someone that can post it. My email add is ron [email protected]

Ron sent you an email.

Vergil

Ol' Ron · 08-12-2010, 09:24 PM

Didn't get it.

[email protected]

Try again, I can send you several pics of things we've done. Some work some don't.

Vergil · 08-12-2010, 09:40 PM

Quote:

Originally Posted by Ol' Ron

Didn't get it.

[email protected]

Try again, I can send you several pics of things we've done. Some work some don't.

Email sent.

Vergil

Bassman/NZ · 08-12-2010, 10:28 PM

The older I get the less I know.

Heh heh... join the club....

Vergil · 08-12-2010, 10:37 PM

Ron sent me a picture of the exhaust port after it was modified so will share it, nice work Ron.

Vergil

Craig CT · 11-21-2011, 11:20 PM

I think some of the new folks might enjoy this old thread,Craig.

robert dick · 11-22-2011, 07:31 AM

used to run a 3 7/16 x 4 flatmotor @ Sanford Maine back in the mid 50's, always wondered if i met Walt at one of these meets-- i had purchsed the block from a fellow named Garvin Cooper @ new england speed--he used to run @ Norwood Arena.

Henry Floored · 11-22-2011, 07:44 AM

One of the best threads on the Ford Barn in my opinion. Love to learn from the Masters. In fact I always thought it would be so cool to have a Flathead "Summit" where the best of the best could gather in one place and share knowledge and experience. I could envision cool seminars covering subjects like porting and camshaft design. How about cracked block repair? Flathead trivia games and such. Maybe a little dyno flogging to put theory to the test. I really think this could be a great thing.

Henry Floored · 11-22-2011, 07:50 AM

Quote:

Originally Posted by robert dick

used to run a 3 7/16 x 4 flatmotor @ Sanford Maine back in the mid 50's, always wondered if i met Walt at one of these meets-- i had purchsed the block from a fellow named Garvin Cooper @ new england speed--he used to run @ Norwood Arena.

I have an 8BA block that is bored to 3 7/16". The pistons are cast and they are for the 3 3/4" stroke. That's about 275 cubes the hard way. The block is in tough shape though, gonna take some TLC to bring her back to life.

Ralph Moore · 11-22-2011, 10:14 AM

So I've got an extra 8BA block that's bored to .125 over(3.312) with one cyl sleeved, Can it be safely bored more? I know that every one recommends "sonic testing" but I don't think anyone here can do that.
When you say "sonic" here, the guy says "Bring me back one of those footlong hotdogs while your there".

Flathead · 11-22-2011, 02:29 PM

Interesting to see how many here have sliced up a block for research. I have a sliced up port much like hotcoupe's. Did it with a sawzall and a lot of help taking turns. That was some hard iron.

tiquer · 11-23-2011, 11:57 PM

Wow this is priceless info thanks guys but keep it going

alanwoodieman · 02-17-2012, 02:04 PM

OK tried to read thru to get opions on what limit there is to boring a flatty and got a head ache, Here is my question--have 3 1/16 41 engine with raised intake deck, worn out even further the sleeves. I have a set of 3 3/16 40 over pistons I could use-do you think I will overbore my block to use these pistons. A few years back I had a 40 merc block ( 3 3/16) with large journal crank and it was 40 over and these blocks look the same

richard crow · 02-17-2012, 02:47 PM

you boar a 32 - 36 21 stud to more than 060 you can always rent it out to heat a 6 story building

alanwoodieman · 02-17-2012, 03:45 PM

so that info may be good but not relevant to what I am asking

Ol' Ron · 02-17-2012, 05:24 PM

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No problem boring the 41 block to 3 3/16, after you remove the sleeves that's only another .040" This will however creat a small lip that will prevent the installation of rings I use a special cutter in the boring bar to remove it. OR you can bore to 3 3/15 +.030 ant this will remove the ridge.. OR you can sonic test the block and bore to 3 5/16.

alanwoodieman · 02-17-2012, 06:10 PM

thanks' Ol' Ron that is what I wanted to know.

out plowing · 02-17-2012, 06:42 PM

Not to hijack the thread, but reading all these posts this has left my head spinning. SO! for all you Flathead enthusiasts, I am looking to build a 8BA with 2x2 intake for street use. I plan to clean up the ports from years of carbon build up. My worry is that it is already bored 60 over, I plan to sonic test the walls and bore it out to 80, 100, or 125 over and use a stock Merc crank. I am stumped over what cam to use. I know that everyone has their favorites, but what do you all recommend for a good street use that has a good thump at idle.

robert dick · 02-17-2012, 07:06 PM

had a 3/ 7/16 x 4 in my 48 conv. bought the engine from New England Speed used -- ex Norwood arena engine--used to drive to Sanford last Sun of the mnth from Arlington Ma, race all day then drive home --often wonder if Walt and i crossed paths back then.

Walt Dupont--Me. · 02-17-2012, 08:14 PM

Quote:

Originally Posted by alanwoodieman

OK tried to read thru to get opions on what limit there is to boring a flatty and got a head ache, Here is my question--have 3 1/16 41 engine with raised intake deck, worn out even further the sleeves. I have a set of 3 3/16 40 over pistons I could use-do you think I will overbore my block to use these pistons. A few years back I had a 40 merc block ( 3 3/16) with large journal crank and it was 40 over and these blocks look the same

Alan, I think 3-3/16 + .040 will work fine on that 41 engine. I've built alot of those engine by removeing the sleeves and boreing out .045 to 3-3/16. I wouildn't be afraid to go another .040 You stick your finger down the water hole next cly and feel the thickness of those blocks, There really thick. Walt

joel · 02-17-2012, 08:37 PM

L 100; aggressive idle and most report good performance. Do a search for L100; there are many threads.

denverslim · 02-17-2012, 08:53 PM

Hey Vergil, with the scarcity of good blocks, these days, do ya think a good welder can fix that sawed up one of yours and getter goin again?...slim

Vergil · 02-17-2012, 09:27 PM

Quote:

Originally Posted by denverslim

Hey Vergil, with the scarcity of good blocks, these days, do ya think a good welder can fix that sawed up one of yours and getter goin again?...slim

hahaha maybe a good welder and a bunch of block filler, I have been looking for another block but as you mentioned they are getting pretty hard to find in my area.

Vergil

Lawson Cox · 02-17-2012, 09:52 PM

I have never found anything boring about the flathead. Couldn't resist the pun.

alanwoodieman · 02-17-2012, 11:15 PM

We are going to do a sonic test, even if I have to purchased a tester. I have been reading on the procedures and it is not really very hard to do. Will keep everyone informed as we build this engine. Thanks Ol Ron

elwood · 02-18-2012, 12:00 AM

wow I just spent 2 hours reading this thread, dont know how Iv missed it.
Damn good reading.

Bassman/NZ · 02-18-2012, 01:29 AM

Quote:

Originally Posted by elwood

wow I just spent 2 hours reading this thread, dont know how Iv missed it.
Damn good reading.

Heh heh ..... me too....

steve tansy · 06-23-2014, 12:19 AM

i have purchased a set of 3 3/8 pistons the seller says their fore inch stroke they check out 3 3/8,but not sure if they are for my 4 inch crank can you please help my engine has not been tore down yet, is thear any way to measure the pin location to see if they are correct for 4 inch crank they are silvolite pistons does not any nombers on pistons but they check out to 3/8 what do you thank thanks steve

Snouts out · 06-23-2014, 04:30 AM

If you hot rod e'm,you better know what you're doiing,especially the carbs...!

Ol' Ron · 06-23-2014, 08:17 AM

The quickest way to check stroke of a piston is to compair the wrist pin location to another piston ofknown stroke. The pin is closer to the top of the piston with the longer stroke, by 1/8"

steve tansy · 06-23-2014, 09:28 AM

thanks, i thought that it could be done on engine likes the engine is not tore down, do you have a measurement from a 239 stock piston that you could give me from the center of wrist pin the top edge of piston, by the way the the new 3 3/8 pistons are three ring pistons tell me and tell me if your measurement is to top edge or at the slight dome thanks so much, steve this would help so much

scooder · 06-23-2014, 03:17 PM

Just measured a stock 3 3/4 stroke piston (239) from the top of the wrist pin hole to the edge of the crown, not the top of the dome, but the start of it. I got 1.179".
For a 4" stroke you should have about 0.125" less.
Hope that answers your question.
Martin.

steve tansy · 06-23-2014, 04:19 PM

yes, that is what ron said to do i understand this i my problem right know i have not disassembled my engine i was hoping someone out there could please measure a 239 piston for me from middle of pin to top edge to the top edge of piston or crown thanks. steve

scooder · 06-23-2014, 04:40 PM

You can use the measurement I gave you. You have the 3 3/8 pistons Sat there, measure them from the top of the wrist pin bore to the edge of the crown. If it's the same, they're 3 3/4 stroke, if they measure close to 0.125" less, they are 4" stroke.
Get it?
Martin.

scooder · 06-23-2014, 05:10 PM

Your reply has disappeared! Where did that go?
There must be ghosts.
Martin.

Ol' Ron · 06-23-2014, 05:30 PM

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There are several kinds of pistons, basically street and racing. And among these there several types available. For street they're the 4 ring thermal strut pistons like the stock ones and hypercritic3 ring like the Egge and others. These can have tight piston to cylinder wall clearance for better oil control. For racing they're the inexpensive cast pistons or the more expensive forged pistons. These require much larger piston to cylinder wall clearance due to expansond caused by heat. However there is a very nice forged piston of material that allow them to be fit very tight, but expensive. You must check with the piston manufacture what clearance they recommend.

steve tansy · 06-23-2014, 06:09 PM

THANKS, Martin, sorry for the mix up on my end your right .125 less than from .179 is .1054 4 inch stroke right on.Thanks again you have help me veary much .Steve

Walt Dupont--Me. · 06-23-2014, 07:26 PM

Quote:

Originally Posted by robert dick

used to run a 3 7/16 x 4 flatmotor @ Sanford Maine back in the mid 50's, always wondered if i met Walt at one of these meets-- i had purchsed the block from a fellow named Garvin Cooper @ new england speed--he used to run @ Norwood Arena.

CRS, Robert, what was the name of that guy that ran at Sanford back in the 50's, his name was on the back of 32 4dor? I believe he was in a wheelchair and built that engine. He had a young fellow drive the car. I remember standing behind that car when it took off down the 1/4 mile. It had wicked torque, I remember he usually turned 103-104 mph. I always wondered what he had it that engine. Walt

scooder · 06-24-2014, 01:30 AM

Quote:

Originally Posted by steve tansy

THANKS, Martin, sorry for the mix up on my end your right .125 less than from .179 is .1054 4 inch stroke right on.Thanks again you have help me veary much .Steve

No problem bud, glad to help.
Martin.

chuck stevens · 06-24-2014, 06:15 AM

Hey, as long as we have some of the best minds on flatheads present answer one question for me. What purpose does having the center lines of the valves not the same on each bank? It must of been intentional, because the 85 and 60HP both have a three degree difference. Also the cam CL isn't lined up with the Crank CL. Thanks Chuck S.

Tim Ayers · 06-24-2014, 06:32 AM

Quote:

Originally Posted by chuck stevens

Hey, as long as we have some of the best minds on flatheads present answer one question for me. What purpose does having the center lines of the valves not the same on each bank? It must of been intentional, because the 85 and 60HP both have a three degree difference. Also the cam CL isn't lined up with the Crank CL. Thanks Chuck S.

I am not pretending to be an expert and I'm curious about this as well. If I recall correctly, I thought I read that it has something to do with the crank or cam not being 100% centerline in the block.

I can be way off, but has something to do with the way they cast the block that caused the need for the valve angles to be different from bank to bank.

Experts, please enlighten us.

Ol' Ron · 06-24-2014, 07:01 AM

The definition of EX-Spurt is: An EX, is like an Ex wife or Ex president. A spurt is a drip under pressure. So an expert is just a drop.

JWL · 06-24-2014, 10:43 AM

The cam being slightly shifted on the X axis required adjustments to be made so all the same valve parts could be used for each bank. Ford engineers decided on differing valve angles to be designed so all the components within the valve group can be the same part #--length--height--etc.

Maybe I am just a "drop". But a rather large one.

Ol' Ron · 06-24-2014, 01:35 PM

Atta Boy John. I can just picture you with a coupla Beagles. Did the Alagator ever come back?

Pete · 06-24-2014, 02:00 PM

As a side note, when Ford moved the valves farther away from the cylinders in 1946 to alleviate cracking between the valve seat and cylinder, they elected to go cheap and did not change the indexing on the cam.
The technical explanation for this is long and involved but the basic reason was tooling cost because they knew there were going to be major changes to the engine in 1949.
The cams from 1946 to 1948 were ground on the same index as the 1942 and earlier ones.

Tom Walker · 06-24-2014, 06:19 PM

Quote:

Originally Posted by Pete

As a side note, when Ford moved the valves farther away from the cylinders in 1946 to alleviate cracking between the valve seat and cylinder, they elected to go cheap and did not change the indexing on the cam.
The technical explanation for this is long and involved but the basic reason was tooling cost because they knew there were going to be major changes to the engine in 1949.
The cams from 1946 to 1948 were ground on the same index as the 1942 and earlier ones.

Why does moving the valve head make any difference? if your not moving the stem in relation to the cam, the timing will remain the same wont it?

russcc · 06-24-2014, 06:35 PM

Walt, sent you a PM. That was Carroll Sleeper's Fordor.

Ol' Ron · 06-24-2014, 07:29 PM

I think the lifter bores went with the valves

Pete · 06-24-2014, 07:41 PM

Quote:

Originally Posted by Tom Walker

Why does moving the valve head make any difference? if your not moving the stem in relation to the cam, the timing will remain the same wont it?

The valve timing to the engine will remain the same but the angle of the valves between the 2 banks changes. (bank separation) Therefore, the bank separation has to be changed on the cam.

4tford · 06-24-2014, 08:24 PM

hope this pic works

07-24-2010, 05:17 PM	#1
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Boring a flathead Boring a Flathead depends on your age. 55 and under .060, fore 55 .125, over 7o .182. and if your like Rumble seat, who is older than dirt. .250. And it still runs cool, nice torque motor .

07-24-2010, 05:30 PM	#2
NealinCA Senior Member Join Date: May 2010 Location: Central Coast, Calif. Posts: 839	Re: Boring a flathead I bored mine .040 at 40.

07-24-2010, 08:03 PM	#5
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead Pete, My first flathead was 3 3/8 X 3 3/4. bought the pistons from Von Eslers Speed shop in Chicago. Had the block bored in Ft Athinson Wi in 1950 by the Ford garage in town. When thwy saw the size of the pistons they refused to bore the block unless I paid in advance. 5 bucks a hole. I bought a used cam and lifters at the same time, don't remember which one. That was a while back. Two duces and milled stock heads. I'd like to build another.

07-24-2010, 08:07 PM	#6
Walt Dupont--Me. Senior Member Join Date: May 2010 Location: Gardiner Me. Posts: 4,200	Re: Boring a flathead Sponsored Links (Register now to hide all advertisements) I built a 3-3/8x4-1/8 =296 when I was 17 that was 57yr's ago. 3 duces, almquest cam. In a 39 coupe. Use to drag race in Sanford Me. Walt

07-25-2010, 06:22 AM	#8
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: Boring a flathead Here we see examples of "the older I get the better I was" syndrone. Such BS is ok so long as you make unknowing viewers aware that there are few facts available within.

07-25-2010, 08:49 AM	#9
Al K. Member Join Date: May 2010 Location: Arlington Hts, IL Posts: 81	Re: Boring a flathead It is nice to see the face of the person writing. Gives it that personal feeling. Al K.

07-25-2010, 10:16 AM	#10
ford1 Senior Member Join Date: May 2010 Location: oroville ca. Posts: 1,554	Re: Boring a flathead Hey Pete, been there, a flat head block was meant to be bored as far as you could, .187, no need to bore to anything else if you were going to street rod it, run mine 3/8 with a merc crank, 4:55 gears, 400 jr cam, solid lifters, adjustables were junk even back then, 2 afb jugs, noting could out run me for the first 100 yards, not even the olds rocket 88's, i could buy flatheads at the wrecking yard for $15 apiece, i still have one engine ready to build with all the pieces stored in my garage, maybe my grand son will like it, my sons all use the chevy v/8's, where did i go wrong?

07-25-2010, 10:26 AM	#11
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead This isn't BS, it's embellishment.

07-25-2010, 11:54 AM	#12
PeterC Senior Member Join Date: May 2010 Location: Connecticut Posts: 855	Re: Boring a flathead [QUOTE=experience the back slapping acceleration and the screech of air going down 4 48's at full throttle...They will never experience the rump rump idle of a 280 degree cam as you idle down the street at 30 mph. They will never experience the sound of the engine turning 6000 as you bang the next gear... I always wonder if there are any TRUE enthusiasts left out there like we were in the 50's when almost everyone drove their hot rods to work every day and had at least one stoplight race a day. We drove to the drags every weekend and raced. No trailers or tow bars. I guess I am preaching to an audience of one though.[/QUOTE] I'd like to think I drive my flatheads "enthusiastically" but with extreme horsepower I am respectful of my 39 trans and Columbia as the weak link! - based on your "back in the day" description - just curious how often you blew things up when you pushed like that! Last edited by PeterC; 07-25-2010 at 03:01 PM.

07-25-2010, 11:56 AM	#13
Mick/mo Member Join Date: May 2010 Location: Rock Port Mo. Posts: 65	Re: Boring a flathead 6000 rpm. ?

07-25-2010, 02:55 PM	#16
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead Pete, It would be nice to know Just what you did to a Flathead to get this type performance. I can't get anyway near it. But I've never run fuel.

07-25-2010, 10:15 PM	#18
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead I must say that's an impressive engine. As you know I built my own flow bench before I wrote my book, just for kicks, but it never gave CFM just Percentages. Later I had the opportunity to use a professional unit. In an effort to gain impressive flow numbers I tried every possible modification to the ports to gain more flow. Big engines need more flow than a small one and 10-12:1 CR impedes flow. I and many others have looked for the Holy Grail of Flathead power and I believe your the only one that's found it. Thanks for the summery of your engine, wish I could have seen it run. Take care.] Ol' Ron

07-26-2010, 01:09 AM	#21
HotRodmicky Senior Member Join Date: May 2010 Location: Germany Posts: 249	Re: Boring a flathead So far we built only one real big engine ( 304ci.) BIG Ports and 1.6 valves etc We buildind a second engine right know.Problem is i don`t know what to do better as number one runs sooooo well I talked to Pete a few times and followed his advice and got a cam(big) from him. The 304 only has a 3x2 with 97s but that engine hauls ass BIG time !!! And runs cool! It lives in a street driven `32 roadster Michael

07-26-2010, 08:50 AM	#22
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead I was building a 296 for my self 3 3/8X 41/8, but sold it to a fellow This is in a 35PU and the acceleration is breath taking. Even surprised myself.

07-26-2010, 06:10 PM	#24
Henry Floored Senior Member Join Date: May 2010 Location: Florida Posts: 583	Re: Boring a flathead This thread is fascinating to me. In my opinion the "Holy Grail" of Flathead performance is to get the edge of the cyl as close to the edge of the intake port. Then using a pop- up piston to give the air charge a large chamber to flow into. So far that's my theory but I plan to put it in motion very soon. I would like to get the largest practical cyl bore dia with the largest intake valve I can get in there, and I'm gonna use pop-ups on the street in my coupe. Don't see why not. Would love to know how you fellas are getting such large cubes. What bore and cyl wall thickness are you ending up with? I want to emulate this situation in a Ford Flathead....

07-26-2010, 06:12 PM	#25
Henry Floored Senior Member Join Date: May 2010 Location: Florida Posts: 583	Re: Boring a flathead Now I'm not talking about actually moving the valves. Rather changing the relationship of the intake port to the combustion chamber. The only practical way I can see is by going to a pop- up affair.

07-26-2010, 06:27 PM	#26
Pete Senior Member Join Date: May 2010 Location: Wa. Posts: 5,407	Re: Boring a flathead Sponsored Links (Register now to hide all advertisements) "Would love to know how you fellas are getting such large cubes. What bore and cyl wall thickness are you ending up with?" Bore = 3.405 Stroke = 4.750 Wall thickness = average .090

07-26-2010, 06:37 PM	#27
Henry Floored Senior Member Join Date: May 2010 Location: Florida Posts: 583	Re: Boring a flathead Awsome Pete, Thanks! What cylinder block type do you find is most capable of handling those large bores? I have an 8BA that is bored to 3 7/16 but has 2 sleeves. It's someone else's project so I don't know everything about it yet.

07-26-2010, 07:37 PM	#29
jdl Senior Member Join Date: May 2010 Location: California Central Coast Posts: 931	Re: Boring a flathead Pete, what is the minimum cyl wall thickness for a street engine and still run cool? I know there are variables. your opinion?

07-26-2010, 09:15 PM	#31
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead Rumble seat (Paul Garagan) is running 3 7/16 in his latest rebuild. He drove out for the chili party from Denver to Vermont and while he was here we had a heat wave that set some records . The temp never got over 185 in either bank. He has .100" wall cylinder wall thickness. The thickest blocks are 99A/T (38-41 Merc/truck) Had one put to 3 3/8+ .030" and still had .170" wall. This block also has the intake valve 1/4" closer to the bore. Good luck, keep us informed

07-26-2010, 09:53 PM	#32
Tim Ayers Senior Member Join Date: May 2010 Location: NJ Posts: 6,177	Re: Boring a flathead Pete & Ol' Ron: Much love for you both. You know that and I've song your praises numerous times. Pete: I can't help to think that your walk to school was also uphill both ways... I think one of the biggest differences from back in the day and today is that you could purchase a complete balanced 4.25" stroker kit for $125.00. Today, one custom made piston goes for that. Yes, I understand Smokey said, "Speed costs, how fast you want to go?" But the '50's are long gone. Other issue is, back in the day, you were tripping over 99A blocks. Today, consider yourself blessed by the flathead gods if you find any good block on the first shot. That being said, I do believe in going big or go home. If you are going to bore it .030", what's the point in IMHO. See what I mean. And like Ol' Ron says: Keep 'um runnin'

07-27-2010, 10:14 AM	#33
HotRodmicky Senior Member Join Date: May 2010 Location: Germany Posts: 249	Re: Boring a flathead Has anyone tried to build a "squared" engine? I mean stroke is the same as the bore..... I know the closest you get is 3 3/8 bore and 3 3/4 stroke. But what if you destroke it alittle.... Then special pistons and small CCs ...... Has anyone tried that? Michael

07-27-2010, 10:53 AM	#35
39cent Junior Member Join Date: Jul 2010 Location: socal Posts: 1	Re: Boring a flathead I experienced the acceleration of a 296 inch flathead driving my buddy,s duece roadster. We beat 56 4 bbl chevys, but when the '57 dual quads came out they could get us. With 25 tooth lincolns, and 354 rear gears, we had to do rolling starts. But that baby would go and we could stay with vettes in the mountains. Three 97's, potvin eliminator, H&C mag, Ansen built motor, it was hard to drive downtown. Of course in those days there were few muscle cars around. flatheads still held thier own. It had done 122 at el mirage by a previous owner. believe it or not.

07-27-2010, 11:03 AM	#36
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead I like the 258ci engine because the port valve area can feed this to a higher RPM. WITH POWER. Having run a number of Dyno ests on Flatheads, they all seem to fall off after 45-4800 RPM. Sure they'll turn 55-6000 but the torque is gone. Very long cams with hi lift, and you can push this up abit, But the ports are th limiting factor. That's why Kong Jackson and Dick landy built their 16 port blocks. In Landys case the engines were supercharged and produced over 500 hp. Back in the real world we have to use what Henry gave us. Porting and reliving work well at hi RPM, but offer little in the way of performance in a street engine. I have a 3 3/8X3 5/8 crank assy and if I can find it , I'll sell it Cheep. Tell us how it works.

07-27-2010, 11:08 AM	#37
Tim Ayers Senior Member Join Date: May 2010 Location: NJ Posts: 6,177	Re: Boring a flathead "But that baby would go and we could stay with vettes in the mountains." 39 Cent It was only a matter of time until the infamous beating a Vette story worked its way into this thread

07-27-2010, 08:45 PM	#39
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead Well this is a conundrum, since I moved I haven't seen it. I know where the crank is, but the rods and pistons are a mystery. Give me something to do tomorrow.

07-27-2010, 09:08 PM	#40
Bassman/NZ Senior Member Join Date: May 2010 Location: Napier, New Zealand Posts: 2,001	Re: Boring a flathead Looking at a square motor from the other perspective..... what stops it from being bored and sleeved square? Piston angle? Crankcase clearance?

07-28-2010, 08:51 AM	#43
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead The biggest problem with the long stroke is piston speed. As the valve opens it shouls reach max lift at about 70 degs after TDC. This is when the piston is reaching max speed. the valve begins to close at around 135 degs and the piston begins to slow down. At very high RPM's the piston runs away from the intake charge, effectively de-stroking the engine. I di believe a pop-up piston will breath better. There are a coupla things you can do to do this without spending allote of money. Using a 3 3/4 strole piston on a 4" crank, then recessing the piston .125 into the head. Now remove the lip created by the transfer area. This can give aprox 9:1 in a 276 engine. After you build a few dozen engines, you'll learn allote. Good luck. PS Just remember, ALL the power the engine makes has to come through those ports.

07-28-2010, 09:13 AM	#44
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead I've heard of engines punched out to 3 1/2 - 9/16. The cost and reliability of these along with a 4 1/2" crank?? I have a friend that runs a 342ci flathead at the drags, runs in the 10's. He admits he didn't think it would last as long as it has..

07-28-2010, 02:36 PM	#47
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead This is the size of a stock port, not much to work with.

07-29-2010, 01:29 AM	#51
Pete Senior Member Join Date: May 2010 Location: Wa. Posts: 5,407	Re: Boring a flathead "For example the small diameter camshaft combined with equally small diameter lifters. Makes agressive cam grinds a little tough." You really should gather more reliable information before making such statements...It has been shown in dynamic testing that the flathead Ford cam does NOT deflect enough when running to change the timing enough to record on a dyno..You can see absolutely NO deflection with a strobe while it is turning 7000 rpm on a test stand... It may be deflecting but you cannot see it...If you are familiar with strobe testing, you can easily see a deflection of .002...It is a commonly known fact that everything else in the engine will be worn out before the cam bearings....Deflection of the cam would show very early in worn cam bearings. As far as lifter diameter goes, check the diameter of a Chevrolet V8 lifter and compare it to a flathead Ford lifter..Flat lifter Chevys will turn 8000. Flathead Fords will turn that also on a test stand but guess which one will last longer due to much lighter valve train. Plain old rocker arm engines such as the common V8 are a poor compromise as far as performance....They were built that way to sell many units and build CHEAP AS POSSIBLE. In the past, desmodromic valve train was the hot thing as far as high performance went...F1 engines both in cars and motorcycles have always been on the leading edge of development and they both had that technology...When that became obsolete, electronic valve train was the new technology....No cam, NO ROCKER ARMS, no lifters, no push rods...Only valves. GP engines nowdays turn 19000 rpm....they idle at 7000... Rocker arms are Mickey Mouse as far as efficient technology goes. Your mileage may vary. Last edited by Pete; 07-29-2010 at 01:36 AM.

07-29-2010, 06:47 AM	#53
Henry Floored Senior Member Join Date: May 2010 Location: Florida Posts: 583	Re: Boring a flathead Pete, my statement about cam and lifter diameter is not about a deflection problem. It simply means it would be nice to start with a larger diameter blank with which to cut the more aggressive profiles. It simply would give the cam designer more to work with. As far as lifter diameter goes a little more footprint, while stock works 95% of the time, could be beneficial in not exposing the edge of the lifter to the camshaft lobe lifting ramp in the most radical racing cam designs.

07-29-2010, 09:57 AM	#57
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,857	Re: Boring a flathead Well that's allot of information to follow. I don't have that much knowkedge in cam design, I'll leave that to Pete. I ran a 404 for a while ans switched to a 400jr which ran much better in our application. The last cam I used in a racing engine was an Errson D410, it replaced the 400jr. Over the years I tried many cams in a racing application. I was also more knowledgeable about intakes & exhaust, combustion chambers. Light weight crank assys and rear brake drums and wheels. over a period of 8 years we took a 258ci engine with 2 bl carb from 22 sec lap time to 16sec. HOW?? Well let's say we learned alott from our mistakes.

07-29-2010, 10:29 AM	#58
lucky Member Join Date: May 2010 Location: Central Kentucky Posts: 43	Re: Boring a flathead I was thinking Ron said use regular 3 3/4 stroke pistons with a 4" crank for the pop-up setup, that still leaves the cost of special heads? Guess I won't be building one unless could find some heads within reason. Had a friend in about 1960 with a '32 cpe had a 3 3/8 X 4 1/2 popup engine,. Red Cornett Summerset Ky built that engine and welded Merc crank and he proly made the pistons, can't remember what brand aftermarket heads he used. Sure ran though, faster than my chev powered '34 pickup. This is great stuff, keep it going. Seems like he wanted a block stamped with Z? marvin

07-29-2010, 10:37 AM	#59
Tim Ayers Senior Member Join Date: May 2010 Location: NJ Posts: 6,177	Re: Boring a flathead I believe, the "Z" blocks were one of the military versions with high levels of nickel in the mix.