Were to get custom crank?

[moneypit94]

Lately my drive for more power has been getting to me... Im thinking of a new setup with a dart block... Thinking of using the iron eagle 302 block that comes with a 4.125 bore and will allow up to 3.75 stroke or up to a 4.00 stroke with some machine work.

I can't seem to find a crank though.. What is the difference between a 351 crank and 302 crank besides stroke size and weight? Can a 351 crank be turned down to fit a 302?

Im thinking of a 3.75 stroke crank. That would yeild me 401 CI's. Now if i did a 4.00 stroke that would yeild me 427 CI's out of a 302 based block.

I am wanting to do something different.. Maybe even like a 383 or something... But I need to find out some more info and options on cranks...

Right now my thoughts are on a 401 with a cam designed to peak around 6500-7000 rpms, or just a blown 401, or both
Ideally i want to hit over 800 rear wheel horse.. but would settle for anything above 600 and maybe im stretching this but i want it to still be streetable.

Also as far as pistons and stuff goes it looks like i can find chevy stuff that would work.. Just have to have rods that would fit chevy wristpin size and ford crank journal size.

 

[Joes95GT]

You cannot use a 351 crank in a 302 or vise versa. The main bearing journal diameter and rod journal diameters are different. I'm sure bearings are different sizes as well, but could probably be made to fit. I would call a place like SCAT and ask them. They have to offer a custom crankshaft size, but how much you are willing to pay is going to come into affect. The best, most efficient way to make more cubic inches and more power is to put a bigger rod in it. A longer stroke will not have the same affect as the longer rod will.

You know what would be cool? To try to get a 351 out of a 302. You would probably have to get a custom piston that has the ring lands way down at the bottom of the piston, with big valve reliefs. After my current motor goes (which won't be anytime soon), that's what I'm going to try and make.

It's just money. You gotta pay to play....

Joe

 

[moneypit94]

I guess i could make it easy on myself and go with a normal 3.400 (347) crank.. It would end up being a 363.. That would be different... Crank and rods wouldn't be hard to come by... just the pistons now...

 

[331 cobra]

If you want the most stroke possible, buy a 347 crank with stock 302 sized journals, then get a set of chevy 400 pistons (8 of a kind, right or left, I'm not sure) with the shortest compression height possible. Now you just offset grind the crank to make it work with 2" small journal 5.4" rods and an 8.2" deck height. Then just pray that it can be ballenced.

But even if it works out, your rod ratio will be marginal and you want to spin it pretty high. I think you need to take a step back and go with something a bit less radical. You want to do a big bore with a stroke that is really pushing the limits of the 5.0 block, make 800 rwhp and rev it high. That's four different big departures from the norm.

If it were me, I would either build a turbo 331 with a really built bottom end, or just turn up the boost on the 418.

But, if you have to do it, Eagle makes a 5.4" H beam with the 2" journal size.