Compression Numbers Good???

DSPTurtle · 10-15-2011, 02:22 PM

So I tested the compression of the warm motor today. Cylinders 1-6 came back as 122, 122, 121, 120, 125, 125. Right side (passenger side) of motor had a little higher numbers. I did not charge the battery in-between and I did the right side first so I am thinking that contributed to the higher numbers. Or maybe that cam is just a hair different. Anyway, all were within 12 points (10%) of each other so I think that is good.
Anyone got a different thinking on these numbers?
(BTW, I am not sure I got number 4 totally tight so that may be contributing to the 120 when everything else on that side was 125)

jwasbury · 10-15-2011, 02:33 PM

I think I've heard the rule of thumb for compression test is all cylinders register within 10% of each other...looks like you hit that. Absolute value is of less importance so I have heard. Did you have the throttle open or closed?

DSPTurtle · 10-15-2011, 03:06 PM

Quote:

Originally Posted by jwasbury

I think I've heard the rule of thumb for compression test is all cylinders register within 10% of each other...looks like you hit that. Absolute value is of less importance so I have heard. Did you have the throttle open or closed?

Closed. I thought about that 4 cylinders into it and said, aww fhuk it... and left it closed for the rest.