Mahle s2k pistons
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Originally Posted by wadzii,Jul 15 2010, 06:40 AM
Yes, 87 and 87.25
If you are big turbo and need ~0.005" pw clearance then std size will probably work fine, if you want anything less than 0.004" then go with 0.25mm oversize. Both my blocks (one pretty beat up, one really good) came out a little to big for the NA pistons. Mine came out to 0.0035" which Mahle says is too much, however i dont notice any piston slap.
The low compression pistons are 2618 alloy, which will work good with more p-w clearance, the high compression pistons are 4032 which dont expand nearly as much.
If you are big turbo and need ~0.005" pw clearance then std size will probably work fine, if you want anything less than 0.004" then go with 0.25mm oversize. Both my blocks (one pretty beat up, one really good) came out a little to big for the NA pistons. Mine came out to 0.0035" which Mahle says is too much, however i dont notice any piston slap.
The low compression pistons are 2618 alloy, which will work good with more p-w clearance, the high compression pistons are 4032 which dont expand nearly as much.
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From: Around
Originally Posted by wadzii,Jul 15 2010, 09:19 AM
0.0008" to 0.0011"... which is why you see so many with scuffed up pistons/cylinder walls.
thats way too tight for a motor like this
thats way too tight for a motor like this
So if I understand what you are saying, if I used this piston "S2K181425P11: 8.9:1, F20C1, Ø87.00 " for my F22c, it will equate to a 9.5.1 compression ratio with a PW clearance of ~.005 ?
Apologize for the questions, just trying to understand the math here.
Thanks
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From: Raleigh, NC
I would expect a "GOOD" stock bore motor to be ~0.004" after its honed round/straight
I would expect a "worn out" stock bore motor to be in the 0.005-0.006 range after its honed round and straight.
So for a turbo motor i'd roll with the stock bore and hone it till the bores are round and straight. vertical scratches dont hurt much at all and if there are a couple here and there I wouldnt worry about it.
For an NA motor, go over size, get the clearance in the 0.002-0.003 range
I would expect a "worn out" stock bore motor to be in the 0.005-0.006 range after its honed round and straight.
So for a turbo motor i'd roll with the stock bore and hone it till the bores are round and straight. vertical scratches dont hurt much at all and if there are a couple here and there I wouldnt worry about it.
For an NA motor, go over size, get the clearance in the 0.002-0.003 range
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From: Phillips Ranch 909!
Originally Posted by wadzii,Jul 15 2010, 11:36 AM
I would expect a "GOOD" stock bore motor to be ~0.004" after its honed round/straight
I would expect a "worn out" stock bore motor to be in the 0.005-0.006 range after its honed round and straight.
So for a turbo motor i'd roll with the stock bore and hone it till the bores are round and straight. vertical scratches dont hurt much at all and if there are a couple here and there I wouldnt worry about it.
For an NA motor, go over size, get the clearance in the 0.002-0.003 range
I would expect a "worn out" stock bore motor to be in the 0.005-0.006 range after its honed round and straight.
So for a turbo motor i'd roll with the stock bore and hone it till the bores are round and straight. vertical scratches dont hurt much at all and if there are a couple here and there I wouldnt worry about it.
For an NA motor, go over size, get the clearance in the 0.002-0.003 range
I was planning on buying a new complete shortblock from Honda and just pulling the pistons and swaping in a set of these..
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From: Phillips Ranch 909!
Originally Posted by wadzii,Jul 15 2010, 05:20 PM
i'd say measure the stock piston, then measure the Mahle piston, figure the stock stuff has 0.001" clearance, you'll know from there.
I'd hate to spend the 2K on the block to find out I still need to bore/hone the cylinder bores...
The whole idea with going with a fresh block from Honda was so that I wouldn't have to have anyone touch the cylinders and it would be "perfect"..
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From: Around
Originally Posted by TRBOKEV,Jul 16 2010, 05:39 AM
I'd hate to spend the 2K on the block to find out I still need to bore/hone the cylinder bores...
The whole idea with going with a fresh block from Honda was so that I wouldn't have to have anyone touch the cylinders and it would be "perfect"..
When I've had blocks honed/bored in the past, I've given them the pistons, and told them what p/w clearance I want, and they do that for you.
Your taking a gamble if you buy a new block, and want to drop those in.
Would it work, probably, but certainly not the right way to do it.