how to work out compression ratio - Saxperience

pug106turbo · 3rd December 2002, 21:41

hi there i know you have to lower compression but how do you work out to lower it to correct ratio

Simo^p · 4th December 2002, 07:02

Its something that i've been meaning to work out the calculation for the saxo's for a while now.. (might get around to doing it)

Most people would tell you to titrate a liquid into the cylinders... but I cant see many people bothering to do that... or even knowing how to use a burette. <img src= "smileys/silly.gif">

If you know, or can grab a few values fom a haynes or workshop manual you can calculate it...

Here's a link you may find useful??

Compression ratio calculation

pug106turbo · 4th December 2002, 16:27

cheers

Hows is your compression lowered

Simo^p · 4th December 2002, 17:22

Two 2mm gaskets.

pug106turbo · 4th December 2002, 23:40

Where did you buy them from or are they special ones

Simo^p · 5th December 2002, 03:09

STd from citroen.... not sure what material the gaskets for your engine are made from though?

pug106turbo · 5th December 2002, 03:17

well am putting mk1 rallye head on so what head gaskets would i use then

Simo^p · 15th January 2003, 01:24

I don't suppose you have the relevent formula written down on the back of a fag packet do you John? (Axsaxoman)

axsaxoman · 15th January 2003, 01:31

yep

cr=cv+ccv devided by ccv

cv=cylinder volume

ccv= combustion chamber volume

don,t forget to calculate volume in gasket and add to both

axsaxoman · 15th January 2003, 01:32

Oh and this presumes pistons are level with top of block,

if not you must add or subtract any ups and owns in piston shape