How Much Crank to Buy

[Dennis Jarrell]

I have been looking at new cranks for my 8BA and I was wondering since I'm buying all new stuff would I be wrong in buying a 4.25 stroker?

Thanks,
Dennis

[Straightpipes]

Dennis, really need some more information. Are you going racing? Are you familiar with the Ford flathead engine? Putting a stroker crank in there changes everything........

[Dennis Jarrell]

The plan is for a very hot street motor for my 35. 3 5/16 bore by 4.25 stroke. Edlebrock heads, three 97's, either a Isky 404 or the biggest comp. thumper cam.

[trainguy]

I have a 4.25 stroker in my 46 Merc.[59] block.It becomes a torque monster.It does not seem to rev as quickly as a stock stroke engine,and is not quite as smooth
.It has a Scat crank with "H" beam rods.It was a bear to ballance.

[19Fordy]

If you want a monster flatty and have the dough check with www.shadowrods.com
Mark Kirby has a huge flatmotor "in the works."
He used to be in Dundee, MI.

[Lawson Cox]

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<LI class=sa_wr>Depends on how high you want to get. lol




<LI class=sa_wr>Urban Dictionary: crank


www.urbandictionary.com/define.php?term=crank
Slang, noun. “Crank” is slang for a low purity, crystallized Methamphetamine that is administered in a powder form. Crank, like all other Methamphe...

[Dennis Jarrell]

Is this supposed to be funny?

[Lawson Cox]

Not necessarily, but I couldn't resist.

[Pete]

Originally Posted by Dennis Jarrell

The plan is for a very hot street motor for my 35. 3 5/16 bore by 4.25 stroke. Edlebrock heads, three 97's, either a Isky 404 or the biggest comp. thumper cam.

Don't stop at 3 5/16 bore as long as you are going to a 1/2 inch stroke.
Go 3/8. That will still leave you at least 2 cleanups for later rebuilds but the chances are the first bore job will outlast you.

You don't want a 404 cam. It is not economically feasable for a street engine. Granted the 404 is probably the best street cam for a "big" flathead but there are other issues such as cost of lifters and machine work to install the valve train properly. I'm saying this as the last one in the world making lifters for the 404.
A Potvin Eliminator would be my choice. Uses stock lifters and easy to install.

[Dennis Jarrell]

The reason I wanted the 404 cam is because a good friend of mine has one in his and runs so good and has had no trouble with it. It has been running for many years. The reason I was going to stay at 5/16 was also because of my friends first flattie that was 3 3/8 had worn the cross hatch at the studs in the bores after a just a few miles so we thought the bore was too much.

[Pete]

Originally Posted by Dennis Jarrell

The reason I wanted the 404 cam is because a good friend of mine has one in his and runs so good and has had no trouble with it. It has been running for many years. The reason I was going to stay at 5/16 was also because of my friends first flattie that was 3 3/8 had worn the cross hatch at the studs in the bores after a just a few miles so we thought the bore was too much.

As I said, the 404 is a great street cam but it was primarily designed as an all out race cam. I have run them on the street many times in several different size engines and they always perform great. They are also a big maintainence item that needs to be looked at periodicly.
I have reground many of them and never seen one that ran on the street that wasn't worn badly at 5000-7000 miles. They have a lift rate of .010 per degree² and that equates to WEAR at low rpm's.

The reason your friend's bores wore at the studs is the block was not honed with a torque plate so the bores were not round.
I have been running flatheads with 3 7/16 bores since 1952 and never had any indications of distorted bores. We ran some of these with 100% nitro. Even ran picric acid and hydrazine in one of them.

[JWL]

I agree the 404 cam is a uninformed decision for any engine which will be street driven. In fact, the wear issues are very significant for even a competition engine. And, the list of cams better suited for street applications is long.

With regard to bore size the 3-5/16 is appropriate for a street build.

Regarding the crank there is no suboptimal points to the 4.250 stroke if purchased as a balanced assembly, except, the pistons will be forged and provide some minor noise until warmed up and careful clearancing examinations are necessary where the rods pass by the block and cam.

[Fibber Mcgee]

Originally Posted by Lawson Cox

Not necessarily, but I couldn't resist.

I laughed so I guess it was funny.

[Dennis Jarrell]

Actually the block was honed with a torque plate. Thanks to every one for the info. Has anyone tried the comp cams thumper series?

[Tim Ayers]

The reason your friend's bores wore at the studs is the block was not honed with a torque plate so the bores were not round.
I have been running flatheads with 3 7/16 bores since 1952 and never had any indications of distorted bores. We ran some of these with 100% nitro. Even ran picric acid and hydrazine in one of them.[/QUOTE]


Pete or JWL:

Do you have an actual torque plate made from a steel plate or do you do it another way; meaning cutting holes in stock heads and using them as the plate?

I'm getting ready to finish bore and hone and want to use a torque plate, but currently don't have one. I had planned to use an old head and cut holes in it with a hole saw. Never cut cast iron before but I'm assuming it is going to be a messy job.

I know Red's use to rent one when Red H. ran the business. I guess I can always call them to find out if they still do.

Thanks.

Tim

[Kube]

Originally Posted by Lawson Cox

<LI class=sa_wr>Depends on how high you want to get. lol




<LI class=sa_wr>Urban Dictionary: crank


www.urbandictionary.com/define.php?term=crank
Slang, noun. “Crank” is slang for a low purity, crystallized Methamphetamine that is administered in a powder form. Crank, like all other Methamphe...

I have to admit, this was the first thing that came to my mind...

[JWL]

Tim, I use heads which have been modified. As I wrote in my book, I use the same bolts/studs, washers, gaskets, and torque values and sequencing that will be used in the final assembly. After both head plates are on I also torque the main caps in place.

I will lend you my modified heads if you pay shipping both ways. Probably more cost than we would ever guess.

JWL

[jerry grayson]

Originally Posted by Dennis Jarrell

Is this supposed to be funny?

If you have no sense of humor, I suppose it is not funny.

[Pete]

Originally Posted by Tim Ayers

The reason your friend's bores wore at the studs is the block was not honed with a torque plate so the bores were not round.
I have been running flatheads with 3 7/16 bores since 1952 and never had any indications of distorted bores. We ran some of these with 100% nitro. Even ran picric acid and hydrazine in one of them.

Pete or JWL:

Do you have an actual torque plate made from a steel plate or do you do it another way; meaning cutting holes in stock heads and using them as the plate?

I'm getting ready to finish bore and hone and want to use a torque plate, but currently don't have one. I had planned to use an old head and cut holes in it with a hole saw. Never cut cast iron before but I'm assuming it is going to be a messy job.

I know Red's use to rent one when Red H. ran the business. I guess I can always call them to find out if they still do.

Thanks.

Tim[/QUOTE]

I had a solid steel one but sold it about 5 years ago.

[Dennis Jarrell]

It just touched a nerv is all and actually it is funny. Left myself wide open!

[Tim Ayers]

Originally Posted by JWL

Tim, I use heads which have been modified. As I wrote in my book, I use the same bolts/studs, washers, gaskets, and torque values and sequencing that will be used in the final assembly. After both head plates are on I also torque the main caps in place.

I will lend you my modified heads if you pay shipping both ways. Probably more cost than we would ever guess.

JWL

Hey John:

Yep, got your book out as reference. Forgot about bolting up the caps until I re-read that section.

I really appreciate the offer and will let you know. I may still give hole cutting the heads a go just for the experience.

Thanks again.

Tim

[Kahuna]

I have the Potvin 425 Eliminator cam in my engine of 290 cubes. The cam was ground by Pete. It is an excellent cam and I couldn't be happier.
I recommend one for whatever you're planning to do.
JMO
Jim

[Bassman/NZ]

Dennis.... listen to Pete and JWL, no-one on the planet knows more than those two.

There are two ways of approaching a hot engine, one is the standard bored/stroked torque monster, the other is the stock bore/stroke high and fast revver. You have to decide which is your best option, but I'll just say I know of two 35s running more or less stock displacement engines that rev to kingdom come and will scare the pants off many an SBC.

[Ol' Ron]

I'm putting together a 294 stroker that I bought from Gary from NY(He's on the barn here) he does the balancing The rods he furneshed cleared the cylinder bore and the L-100 cam. I have a modified stock head as well for a torque plate and I follow JWs method, works well. I use the 74cc Edelbrock heads and founf pd the piston to head clearance to be about .070" on the edge of the cylinders and .090" at the dome, CR checked out at 7.7. I'm having the heads milled 025" to tighten things up alittle.

One interesting note is the clearance over the spark plugs is enoug to run a powertip plug. I've checked 2 different styles of 3/4" reach plugs and both left 2 exposed threads, which will have to be removed. I'll have some pics soon.

[flatjack9]

Originally Posted by Dennis Jarrell

Actually the block was honed with a torque plate. Thanks to every one for the info. Has anyone tried the comp cams thumper series?

I'm building an engine for a fellow who bought the Thumper cam from Speedway. The cam was ground straight up while the timing card called for it to be ground 6 deg advanced. I've ordered a cam gear that will put it where it belongs.

[Tim Ayers]

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Originally Posted by Ol' Ron

I'm putting together a 294 stroker that I bought from Gary from NY(He's on the barn here) he does the balancing The rods he furneshed cleared the cylinder bore and the L-100 cam. I have a modified stock head as well for a torque plate and I follow JWs method, works well. I use the 74cc Edelbrock heads and founf pd the piston to head clearance to be about .070" on the edge of the cylinders and .090" at the dome, CR checked out at 7.7. I'm having the heads milled 025" to tighten things up alittle.

One interesting note is the clearance over the spark plugs is enoug to run a powertip plug. I've checked 2 different styles of 3/4" reach plugs and both left 2 exposed threads, which will have to be removed. I'll have some pics soon.

Ron:

I know I'd appreciate a picture of what the plug looks like in the head after the threads are removed.

I don't doubt that the threads need to be done, but I'm I guess I'm intrigued about how those exposed threads can cause havoc during ignition.

[Dennis Jarrell]

My thought on the 4.25 crank was if the the engine doesn't rev much more than 4700-4800 then why not try to make as much torque as possible on the way and not wind the snot out of it. But I do recall when I was a pup, I new a guy that ran 1/8 over bore with stock stroke on the oval track that ran real good. He sold it and that guy put in a 33 sedan that would wear out most 55 Chevy's. It had edelbrock heads, fenton 3 deuce and 97's, and isky super something cam. So, I guess your guys are right there are many ways to go.