How do you add each cyl compression to get the finial compression ratio of the engine.

"sorry if that didnt come out right"

example:
cyl1. 215 cyl2. 215 cyl3. 215 cyl4. 215 = x??

 

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

 

Thats for adding all you elements together, I just want to know how to add each cyl compression

 

wait...you're trying to calculate your compression ratio based upon the results of a compression test?

because it doesn't quite work like that -- two different things.

 

Correct

 

if you want to know if your engine is health following a compression test, all four numbers should be within factory spec (which depends on the motor you're running) and there shouldn't be much more than a 5% variation across the board.

if you want to know the compression ratio of the motor -- you need to go back to the link i originally sent you.

as far as i know, you can't accurately calculate compression ratio based upon the results of a compression test.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Phoenix_ITR &raquo;</TD></TR><TR><TD CLASS="quote">if you want to know if your engine is health following a compression test, all four numbers should be within factory spec (which depends on the motor you're running) and there shouldn't be much more than a 5% variation across the board.

if you want to know the compression ratio of the motor -- you need to go back to the link i originally sent you.

as far as i know, you can't accurately calculate compression ratio based upon the results of a compression test.</TD></TR></TABLE>
x2, these are 2 different things. However if you know your rings and such are good you can try this maybe. Your comp test should usually be 17-20 times that of your static compression ratio. If you are getting 215 as you example then thats deff high, so i would guess your comp ratio around 11 or 12.0:1

 

Lol well if you think 215 is high (upper 11's - low 12's) then I must be screaming high, 225-235 lol. I;m trying to finish my turbo setup an I have come to the comression part of it. Im trying to figure out how thick of a gasket to get. I dont want to guess and get one to thick, I want to be moderate with it.

 

that is super high, lol. I've seen a d-series where the vitara pistons put them at 8.5:1 and it'll be at 160 in a comp test. You better get a amazing tune, lol.

 

Cranking pressure represents dynamic compression. Cam profile, valve timing, etc. affects this.

As long as your results are consistent (and not very low), you're fine.