I have 4x 9:1 JE pistons for SI's. I would like to know what CR would it give me if I put those pistons in a gsr engine?
did a search but no luck
karl

 

c-speedracing.com has a calulator for that. Try plugging in all the correct specs and it will tell you.

 

thanks but I don't know all the specs of the pistons..they are JE 9:1 CR 20 over for SI's and just want to know what CR they will give in the gsr engine?



[Modified by bcause, 9:29 PM 12/14/2002]

 

i think it would be slightly higher....(or im mixing things up ni my brain ) and its lower sorry, that wasnt much help

 

9.2-9.3 in a gsr

 

~9.1 in a b16 w/ b16 head is going to yield around ~9.8/9.9 in a GSR w/GSR head.

 

thanks guys..
if anyone has exact numbers....



[Modified by bcause, 10:56 PM 12/14/2002]

 

a .20 over B16A piston in a B18C1 (using the GSR rods, block and head) yields 11.4:1 C/R. so i would think that a .20 over piston that yields 9.1 in a B16A motor equals 10.3:1 C/R in a B18C1 motor, a difference of 1.1:1 C/R.

but of course there may be something i'm missing. having the piston displacement specs makes it easier to calculate.

 

http://www.c-speedracing.com/howto/c...c/compcalc.php

 

I asked JE about this when i bought mine, they said my 9:1 B17 pistons would yield 8.5:1 on a B16 head.

So I imagine it you be 9.5:1 going the other way.

 

realy appreciate guys..
spoolinLS: I know but I didn't have all the info needed to calculate..

 

9:2 100% sure

 

sorry 9.2:1

 

I think you're thinking of just the difference in a b16 and a gsr head which is roughly .2 points different compression. Using the calculator on c-speed racing's site, you need a -1.0cc dished piston dome volume to yield a 9.0:1 c/r in a b16 w/ stock 3 layer headgasket and b16 head and a .020" overbore. Use those same specs, but with a GSR block and head and you get 10.0:1 c/r.


[Modified by boostaholic, 5:15 AM 12/15/2002]