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post #2 of (permalink) Old 04-18-2019, 11:06 AM
cocobolo95
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Join Date: Sep 2008
Location: Fruitland Park,Florida
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When you buy a set of pistons, they list the static compression ratio that pistons give. Hoever, it's the dynamic compression ratio that is the important factor in building a high performance engine.

The dynamic compression ratio, takes into account the duration,lift & lobe timing of cam. The size of the combustion chamber and valve size also are taken into consideration for figuring the DCR. Many other factors also are looked at.

Having said this, I suggest you google static & dynamic compression info. Just out of thin air with 15 pounds of boost, I'm thinking around 8.0 to 1 or 7.5 to 1 static compression ratio. The DCR can't be figured until you know all of the components & machine work that is being done.

As an example stock bore engine will have a lower DCR than say a 30 or 60 over bore. Even though pistons for stock & over bore would have the same static compression ratio SCR.

I'm not an expert on boost, but with 15 pounds of it, if it were my engine, it would have all forged rotating system.

Last edited by cocobolo95; 04-18-2019 at 11:09 AM.
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