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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: Brian Hafliger]
#1304047
09/16/12 11:48 PM
09/16/12 11:48 PM
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Joined: Jan 2005
Posts: 3,699
Newport, Mi
Evil Spirit
master
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master
Joined: Jan 2005
Posts: 3,699
Newport, Mi
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Quote:
Quote:
I'm sure this will rattle a few cages - oh well. Setting the block deck height to set your quench/combustion chamber/piston clearance is important, as eliminating mechanical interference and checking compression is again, important. Decking a block solely to square it up? More important to help make the intake seal than anything else - don't waste your time or money if you think there's "magic" power there. There probably isn't 5 HP gained by decking the block just to square it up, since most blocks aren't that far off, usually in the .010 range, and cutting only .010 off a block won't change compression enough for a big power gain. You will get the same power increase by a thinner head gasket. So if you are cutting the block to set piston to deck height - whack away. Otherwise there isn't the gain there by trueing the deck to the mains that lot of people seem to believe. I've heard of a lot of people decking blocks, but not equalizing combustion chamber volumes - HUH - whats the difference? Ones just promoted better I guess. 
Piston to cylinder head quench is main reason to zero deck... .010 tolerance is unacceptable.
Yeah, I covered THAT. But spending $100 to deck a block just because it is .010 off "square" is probably the worst $100 you will spend in a short block, because it does nothing to improve reliability, nothing to improve repeatibility (bracket racing) and is marginal at best on power increase. You would be better off putting that money towards coated bearings, piston coatings, better springs or pushrods, etc., than decking a block just to square it .010.
Free advice and worth every penny...
Factory trained Slinky rewinder.........
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: YYZ]
#1304048
09/17/12 10:59 AM
09/17/12 10:59 AM
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Joined: Jan 2003
Posts: 74,947
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,947
U.S.S.A.
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Quote:
But what?...
(and yes it is one of those cranks)
Have you actually tried fitting it in the block ? The best I could tell the crank was a 1053 material, Hemi 3.75 stroke replacement crank with the mains cut to fit a low deck block, the counterweights are HUGE, close to 7.5 if I remember right. I had my crank cut down to 7.200, balanced nicely after that with no metal added, 3.75 stroke in a 383 using Diamond 1.320 and I can't remember what rod, but it wasn't stock.
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Re: 383/400 stroker - 3.90, 3.91 or 3.92 crank?
[Re: YYZ]
#1304051
09/17/12 11:47 AM
09/17/12 11:47 AM
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Joined: Jan 2003
Posts: 74,947
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,947
U.S.S.A.
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Quote:
John, on that build did you stay with the stock BB journal size or did you have the crank turned down to use a 2.200 journal?
I ended up selling the crank before that project got finished, but it did stay with the stock rod journal size while I owned it.
It may be a wash by the time you are done if the CCJ crank needs to have the rods and mains cut undersize to fix it . the plus is it's 4340 instead of 1053 .
But also make sure the CCJ crank fits the block properly also , watch out for the crank hitting the block before the thrust bearing .
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