compression on pi

realitygt

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so an npi is around like 9:1 compression and a pi is about 10.5:1 compression from what i've read right?

a stock headgasket on a pi is 0.039 compressed so If you used a .060 copper headgasket (since they don't compress) about how much of a decrease in compression would you see?
 

reivaxtorres

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realitygt said:
AaRoN said:
A pi swapped car is 10.5:1 and a pi motor is 9.5:1.
i didn't know that. good to know tho :thumb:


TTT

i thought NPI was like 9.2:1, and the PI motors (not the NPI bottom end and PI heads motor) were supposed to be the same, 9.2:1, but in the later years it gradually went up to like 9.4:1
 

AaRoN

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reivaxtorres said:
realitygt said:
AaRoN said:
A pi swapped car is 10.5:1 and a pi motor is 9.5:1.
i didn't know that. good to know tho :thumb:


TTT

i thought NPI was like 9.2:1, and the PI motors (not the NPI bottom end and PI heads motor) were supposed to be the same, 9.2:1, but in the later years it gradually went up to like 9.4:1

Maybe it changed (PI motor I mean) sometime around the time they went back to Romeo, MI. I know my compression is 9.5:1
 

Jrgunn5150

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Technically, a PI head on a NPI block, is 10.3:1. All PI heads have a 44cc chamber, so any difference is in the piston dish. NPIs are 10.5cc and PI's are 18.5
 
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