compression ratio help
 

I need some help finding my compression ratio of this setup.

b18a1 block with CP Gsr pistons compression 9.0.1 compression height 1.181 cp part number is CP7010.

integra LS eagle rods

block was decked for gasket sealing about .010 over

B16 head, shaved .040 over

head gasket stock thickness.

whats the compression ratio with this setup?

I order a cometic .051mm head gasket to be safe

Re: compression ratio help
 

specs on the piston are 29.525mm compressed height, and -4mm dome. compression w/ that combo come out to 8.60:1 or something like that w/out the block decked .010, w/ block or head shaved .010 it goes to 8.77:1

Re: compression ratio help
 

are you sure? I am under the impression that I am running 10.5.1 compression, I tried using the compression calculator but was not sure about the results. someone at h-t said 9.5.1 which is acceptable, but 8.7.1 does not sound correct. this car is even powerful in N/A form thats not possible at 8.7.1 compression

Re: compression ratio help
 

no i am not sure, all thats according to the compression calculator.

Re: compression ratio help
 

I wish I could get some more input on this I am very paranoid with it. even though I still run 21psi at the track, and 13 psi daily. every now and then 21psi in the streets.

Re: compression ratio help
 

ok well, just believe me then, i dont see how my calculations could be off, unless the compression calculator has a wrong spec somewhere. im not familiar enough w/ B series to see if the deck heights and all are correct on that particular calculator.

Re: compression ratio help
 

if I go with you I would up the boost to 35psi and boom, but it made me feel better about running 21psi without worry. thanks for the help though

Re: compression ratio help
 

comp calculator says 8.7ish
question now is how much do you trust that comp calculator

Re: compression ratio help
 

exactly, i know for sure the D series calculator has the wrong D15 deck height, no telling whats wrong w/ the B calculator. i wouldnt recommend boost level based on compression ratio though.

Re: compression ratio help
 

both D compresssion calcs SHOULD have the correct deck height now......

I know zealautoworks is correct.......

can also do it the correct why, if your good at math :)

Using the 9:1 GSR slugs in your setup, I'm guessing they have a 7cc dish......

I'm coming up 10.48:1 compression with those pistons in your motor.

.5 mm shorter deck + .050" milled are the big factors.