59AB L Block Modify

[dschwartz]

I am having so much fun modifing the flathead. I want to bore the 59AB l block to 3-3/8" with a 4-1/4" stroke a total 304 ci. Speedway has a complete flathead ford rotating assembles, Scat crankshafts, rods, three-ring pistons, and all this is balanced, what do you think.
Dan Schwartz

[harry jackshaft]

it sounds great, but what about flywheel and pressure plate?

[Bassman/NZ]

I have no experience with the Scat assemblies, but have read in different sources that they have a maximum rev limit of just over 5000rpm. That's OK for a street engine, but if you're planning on racing it just be aware of that.

[Krylon32]

Have that block sonic checked before your bore.

[HotRodmicky]

I picked my block from machining up yesterday
Scat 304ci kit
Had it bored to 3 3/8.
Had it Sonic tested
The block really gets thin in some places.....

Wouldn`t do it again....

Go for the 284ci kit.

Or..... get the 4.375 Scat crank and Rods . Ross 3 5/16 pistions for 4.250 stroke
and make it a pop up engine.!!!!
That is what i will do the next time.

Michael

[KiWinUS]

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tell me the advantage of a pop up engine ? Alot of work for very little or no gain I would think , hard to find suitable heads .
Cheers
Tony

[HotRodmicky]

pop up? high flow and high compression.......

in that case it`s a 1/8 stroke difference. 1/8 :2 = 1/16 higher in the head
If really necessary you can redome any head 1/16 ...
Sharp allows a lot more

I used the pop up therm more a joke as 1 /16 is not a real pop up...

Ross has 4.125 pistions in stock, but 4.375 are special order.

A stock head you can shave 1/16 off and still have enough clearence.
Recut the valve pockets and you are fine.

Michael

[Bruce Lancaster]

Flatdog's famous high-12 second 3,000 pound '34 used the 4 1/4 stroke in the blown 307. It had an oil consumption problem on the street.
Flatdog was a relentless engine developer and re-flogged the ring package a couple of times, trying zero gap type and others, and was never able to kill off the oil consumption. He theorized that 4 1/4 was simply too much stroke for the rod length and that piston rocking was defeating the rings, kind of my conclusion too.
His next engine in the development was to be shorter stroke; don't know exact plan, and he died before getting to the results he wanted.
He was as thorough as a builder can get, and perfectly willing to tear his engine apart repeatedly...the package was an intellectual challenge to him, a quest for the maximum street power flathead, and not something he ever regarded as a completed project.

[dschwartz]

Can I offset grind a Merc crank a 1/8" and still use the 8ba rods and bearings?

[KiWinUS]

No you must use 21A or 91A rods with full floating bearings.

[Drunkandgreasy]

Originally Posted by KiWinUS

No you must use 21A or 91A rods with full floating bearings.

Hey KiWinUs,

Can you elaborate for me on why not? I'm interested to know...

Cheers
Hodge

[Bill Steiner]

I agree . I did that many years ago. Bill

[Pete]

Originally Posted by Bruce Lancaster

Flatdog's famous high-12 second 3,000 pound '34 used the 4 1/4 stroke in the blown 307. It had an oil consumption problem on the street.
Flatdog was a relentless engine developer and re-flogged the ring package a couple of times, trying zero gap type and others, and was never able to kill off the oil consumption. He theorized that 4 1/4 was simply too much stroke for the rod length and that piston rocking was defeating the rings, kind of my conclusion too.
His next engine in the development was to be shorter stroke; don't know exact plan, and he died before getting to the results he wanted.
He was as thorough as a builder can get, and perfectly willing to tear his engine apart repeatedly...the package was an intellectual challenge to him, a quest for the maximum street power flathead, and not something he ever regarded as a completed project.

It would have been interesting to find out what caused the oil consumption.
I built 2 engines for customers in the old days with 4 1/2 inch stroke and they were bone dry. (no oil consumption)
My own last engine was 4 7/16 stroke and it was also dry.
I can only theorize that the problem might have been type of rings and wall finish.
The pistons in an engine with a 1 inch stroke are quite short which contributes to much shorter ring life due to rocking and thrust, especially with .010 clearance..Even so, ring life and oil consumption is still tolerable for racing purposes.

[Bruce Lancaster]

This engine was fully streetable, very smooth and docile until you stepped on it.
I would assume oil consumption was only on street when not under boost, but who knows on 1/4 mile use. No fouling or smoking, no leaks...oil just went away.
I got to drive the thing from central PA to Northern NJ when Flatdog became...incapacitated... from Denise's cookies and lots of beer at the Jalopy showdown, and it was quite a trip. At part throttle, it could have been driven to the Mah Jong club by grandma with its automatic trans, felt like a big block when floored.
Would have been even faster without the trunk full of oil...
Seriously considered leaving Flatdog at the rest stop and leaving for Bonneville with his car.
No further history...engine went into an altered after it bent the frame in the '34, and then Flatdog died while still planning his next iteration and breaking in the altered.

[Bruce Lancaster]

And, I would love to know about the oil consumtion and what the streetable stroke limits really are, now that huge strokes are available at the dime store!

[Pete]

Originally Posted by Bruce Lancaster

This engine was fully streetable, very smooth and docile until you stepped on it.
I would assume oil consumption was only on street when not under boost, but who knows on 1/4 mile use. No fouling or smoking, no leaks...oil just went away.
I got to drive the thing from central PA to Northern NJ when Flatdog became...incapacitated... from Denise's cookies and lots of beer at the Jalopy showdown, and it was quite a trip. At part throttle, it could have been driven to the Mah Jong club by grandma with its automatic trans, felt like a big block when floored.
Would have been even faster without the trunk full of oil...
Seriously considered leaving Flatdog at the rest stop and leaving for Bonneville with his car.
No further history...engine went into an altered after it bent the frame in the '34, and then Flatdog died while still planning his next iteration and breaking in the altered.

Great story..I have some pics of Denise and her cookies so I can well imagine what happened....hee hee

[HotRodmicky]

We have a 4 1/4 stroke street engine and no oil consumption other than normal...

[dschwartz]

Hello
Have you had any problems with the Scat cranks, one ford barner said that the Scat cranks have Rev problems.
Thank you
Dan

[joel]

Originally Posted by Bassman/NZ

I have no experience with the Scat assemblies, but have read in different sources that they have a maximum rev limit of just over 5000rpm. That's OK for a street engine, but if you're planning on racing it just be aware of that.

The computer says that this engine would need to flow 106 cfm intake at 4500 rpm. Assuming 240 dur @ .05 and .360 lift and with 1.5 dia. valve. Guesstimate200 hp @crankshaft. This seems reasonable to me,so 5000 rpm limit is ok.

[G.M.]

Dan I'm not into big engines, big problems but if I was going to bore a Ford engine that big I would find a 59-C block that is a Canadian block with thicker cylinder walls and better cast iron. G.M.