What is the stock replacement piston size?
04-01-2004, 03:35 PM
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What is the stock replacement piston size? I tried doing a search and didn't find an answer. I'm replacing the stock pistons with forged ones. What is the factory compression ratio.
Are these numbers right for a STOCK replacement? This is what I'm getting from a dealer on his Ross pistons that he sells.
Bore 3.905
Stroke 3.622
Rod length 6.098
CR 9.0 I don't think this is right
CH 1.326
Net CC -4.000 What does this mean
Pin diameter .945
Are these numbers right for a STOCK replacement? This is what I'm getting from a dealer on his Ross pistons that he sells.
Bore 3.905
Stroke 3.622
Rod length 6.098
CR 9.0 I don't think this is right
CH 1.326
Net CC -4.000 What does this mean
Pin diameter .945
04-01-2004, 03:39 PM
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Originally Posted by ss1le02
I tried doing a search and didn't find an answer. I'm replacing the stock pistons with forged ones. What is the factory compression ratio.
Are these numbers right for a STOCK replacement? This is what I'm getting from a dealer on his Ross pistons that he sells.
Bore 3.905
Stroke 3.622
Rod length 6.098
CR 9.0 I don't think this is right
CH 1.326
Net CC -4.000 What does this mean
Pin diameter .945
Are these numbers right for a STOCK replacement? This is what I'm getting from a dealer on his Ross pistons that he sells.
Bore 3.905
Stroke 3.622
Rod length 6.098
CR 9.0 I don't think this is right
CH 1.326
Net CC -4.000 What does this mean
Pin diameter .945
04-01-2004, 03:54 PM
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Originally Posted by DenzSS
The bore you have listed is for a block that has been align honed. Stock bore is 3.898"
04-01-2004, 10:41 PM
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I suppose net CC should mean difference compared to stock in piston volume above piston pin center line. Negative cc results in less compression. Most 'stock replacement' pistons have -2cc due to valve reliefs and cause some ~.3 point or so loss in compression. 3.905 pistons require a trip to machine shop. Don't let the dealer hone the block using the ghetto procedure described in factory service manual.
04-02-2004, 06:24 AM
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3.898" is the stock bore size from the factory. 3.905" is the standard over-bore that most folks go with, any bigger and you get into a re-sleeve situation.
Align honing the block, while always a good idea has nothing to do with honing the cylinder bores.
Also take into account what cylinder head you are running and what CC your chamber is. That will factor into compression obviously, and it sounds like there was some key info that wasn't translated here.
I'd get more info before making my purchase. Diamond, Ross, JE, all offer a couple of different pistons for each head in the 3.905 bore size. The CR ranges from 9:1-13:0 depending on what cylinder head you are using and chamber size.
Good Luck!!
Align honing the block, while always a good idea has nothing to do with honing the cylinder bores.
Also take into account what cylinder head you are running and what CC your chamber is. That will factor into compression obviously, and it sounds like there was some key info that wasn't translated here.
I'd get more info before making my purchase. Diamond, Ross, JE, all offer a couple of different pistons for each head in the 3.905 bore size. The CR ranges from 9:1-13:0 depending on what cylinder head you are using and chamber size.
Good Luck!!
