91' CRX Si D16a6 SOHC nonvtec
145, 140, 145, 150

decent numbers? or not... I also have a stage3 cam w/ 270 duration and im not sure if taht would effect the numbers.

 

numbers are low- should be at or around 180.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blackeg &raquo;</TD></TR><TR><TD CLASS="quote">numbers are low- should be at or around 180. </TD></TR></TABLE>

Couldn't my cam be the cause of the lower compression #'s?

Stock cams cause valves open and close quicker, so during the stroke the cylinder has more time to compress while the valves are closed

This is a Stage3 w/ 270 duration race camshaft, Would it be why?

Aftermarker cam w/ longer duration keeps the valves open longer so while during the stroke the valves are still open releasing air, thus giving a lower compression number because less air was compacted.


This is an untuned cam w/ stock camgear.

 

If you really want to know, do a leakdown test...

 

compression #'s vary with different compression testers. if the numbers are within 5% of each other you should be fine...

 

Just did a compression test on my car:
1 - 155
2 - 175
3 - 175
4 - 170
I'm a little worried about the #1 cylinder being so low, even though it's within 10% of the others. Should I be worried? I'm doing a leak down test tomorrow.

Oh, the car was fully warm, cranked until needle stopped moving, but I didn't pull the fuel fuse. 92,700 miles on car, mostly stock.

 

Drop a couple of squirts of oil into the spark plug well and test it again. If your reading jumps up, it's the rings, if not it is probably the valves.