Ok, i know this is a very motor specific question, and all builds cr's are not only affected by head, deck and head gaskets. . .but if i were using a 1999 Civic Si Head (resurfaced) on a B18B block, stock b18b pistons and an oem honda headgasket. . .What kind of compression ratio do you think I'm looking at? Is this figure just way too difficult to come up with a good educated guess?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CircuitDA9 &raquo;</TD></TR><TR><TD CLASS="quote">Is this figure just way too difficult to come up with a good educated guess? </TD></TR></TABLE>

you said it...

 

Check out this link... It has a compression calculator...

http://www.c-speedracing.com/h...c.php

 

Depending on how much you cut the head (assuming .007") compression should be around 9.65:1

 

I know about the c-speedracing. . .i'm just kinda sceptical of the accuracy. . .

 

9.65:1 that seems alittle low, I figured it would be more than a stock B16

 

with stock b18b pistons i doubt it.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by KilaB18C &raquo;</TD></TR><TR><TD CLASS="quote">9.65:1 that seems alittle low, I figured it would be more than a stock B16</TD></TR></TABLE>

 

Here is the formula if you want to figure it out for yourself.

C-P+G+D+V
CR= ___________
C-P+G+D

All measurements in CC's
C= combustion chamber volume
P= piston dome volume
G= head gasket volume
D= deck height volume
V= cylinder swept volume