450 to 500 hp 4 speed crank choice

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K.O. SWINGER

K.O. SWINGER

Meeting in the alley since 1976
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I would like seasoned opinions on crankshaft material choice for a 450-500 hp 4 speed. Big clutch and 275 drag radials am considering a 3.58 stroke 340 . My question is would you feel good with a high-end cast crank like a 900 series scat or would you just bite the bullet for forged and never look back.
 
pittsburghracer said:
If it wasn’t a factory cast crank I wouldn’t buy anything cast.
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The stock 360 crank takes almost anything you can throw @ it! Aftermarket not so much. Maybe with the exception of scat cranks. But never used one so not sure. Eagle cast cranks are basically trash.
 
The prices of those must have gone way up since I got mine if that's a true current price. I agree, if $3000 is what you have to spend on one, I'd use a stock forged crank instead for that HP range. IIRC, mine was about $600, but that was several years ago.
 
Forged for sure, don't look back. Cheaper to do it right the first time.
 
Light rods, pistons and my steel 273 crank. The pistons would look like Swiss cheese though.
 
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toolmanmike said:
Light rods, pistons and my steel 273 crank. The pistons would look like Swiss cheese though.
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A guy here just got his 340 back from someone in SC, Mopar Specialist built it and he went to put it in and found it had a small register for the converter ? 273 crank ? what years were they smaller
 
brian6pac said:
A guy here just got his 340 back from someone in SC, Mopar Specialist built it and he went to put it in and found it had a small register for the converter ? 273 crank ? what years were they smaller
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Probably so. I don't know the year breakdown on the registers without searching. He should ask about balance. They either used a lot of mallory or they found 340 pistons that weigh around 570 grams instead of the 735g that the stockers do.
 
toolmanmike said:
Probably so. I don't know the year breakdown on the registers without searching. He should ask about balance. They either used a lot of mallory or they found 340 pistons that weigh around 570 grams instead of the 735g that the stockers do.
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That's a big difference, yeah he called the guy and he is building him another motor to exchange it. I don't think I would trust him at this point. If he is a specialist that this guy claims he should have known this wouldn't work, then he told the guy that it was a 4 speed crank and he thought that what he was using, that's why it wont work.
 
Yeah, on a manual trans it doesn't matter as long as the center hole is machined for a bushing.
 
cudamark said:
The prices of those must have gone way up since I got mine if that's a true current price. I agree, if $3000 is what you have to spend on one, I'd use a stock forged crank instead for that HP range. IIRC, mine was about $600, but that was several years ago.
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Are you sure you aren’t thinking that you bought a “forged” crank. Billet cranks like Crower, Calius, Oliver, etc have always been big dollar items. I lucked out and found a used Calias 4.5 stroke big block crank two years ago for 500.00 for a spare and grabbed it. The one in my 572 cost me 2300.00 plus shipping back in 2008.
 
I sold off a .030 over 340, Scat rods, scat cast crank, Wiseco pistons, rings, bearings, damper, flexplate, etc all new because I was afraid of runnings 9’s with it. Some guy from the east coast made an over 1000 mile road trip for it.
 
K.O. SWINGER said:
I would like seasoned opinions on crankshaft material choice for a 450-500 hp 4 speed. Big clutch and 275 drag radials am considering a 3.58 stroke 340 . My question is would you feel good with a high-end cast crank like a 900 series scat or would you just bite the bullet for forged and never look back.
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What is a Big clutch? Never heard of that brand before. I’d never use a cast crank. Spend a few extra dollars and get a forged crank.
 
i know Ramm built a 697 hp stroker with a scat 9000 that has stood the test of time i run one at 530 hp and spray with a 100 shot over 10 years now pick your poison . both will work fine . there are thousands of 500 plus hp small blocks running the scat 9000 .
 
Breaking a crank is catastrophic. The difference in price is max $400-$500 maybe less. I run a Scat cast crank and shift at 6300-6400 rpm. It is fine where I’m at, but would be uncomfortable taking the next step I need to go quicker with it. That being going roller cam. Don’t paint yourself into a box.
 
448Scamp said:
What is a Big clutch? Never heard of that brand before. I’d never use a cast crank. Spend a few extra dollars and get a forged crank.
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Big clutch is an old school term for heavy plate pressure. There's a reason factory used forged cranks in there 4 speed cars. Combine a serious clutch and drag radials it can really stress a crankshaft.
 
My Mopar billet crank was $1800.00 in 1993.

When we didnt know junkyard cast cranks wouldnt work we got at least two seasons of racing in our dirt cars with a SBC 550 hp and those junk cranks.

. Now that we are smarter we get one or two years out of our $1500.00 Callies, Scat, Lunati or similar cranks with 100 more oomph.

Thank God we know better today...
 
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K.O. SWINGER said:
Big clutch is an old school term for heavy plate pressure. There's a reason factory used forged cranks in there 4 speed cars. Combine a serious clutch and drag radials it can really stress a crankshaft.
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Got it. So what is the benefit of a big clutch?
 
448Scamp said:
Got it. So what is the benefit of a big clutch?
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Lack of slippage, I've always ran 340s and on Max output leave around 45,00 to 5000 RPMs that combined with the drag radials will go through a lighter clutch causing it to wear out quickly(slip) a few hard slips and the clutches toast.
 
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