Let me see if I'm right here. I did a compression test and here's what I got. #1 is 121, #2 is 60, #3 is 120, #4 is 90. Can a set of crower 2 cams effect the compression test that much if the timing off? I don't know how off the timing is, but if it is off, are these numbers normal? The head is brand new with everything upgraded down to a port and polish. The bottom end was fine too. Do you guys think my timing is just off?

idk how cams affect compression but those are really bad numbers. ideally you should be around 180-200ish with no more than like 10% variation between cylinders or something. i think.

does it drive? maybe you didn't do the test properly... was the engine cold?

http://forums.2gnt.com/dcboard.php?az=show_topic&forum=5&topic_id=82122&mesg_id=82122&page=#82129

Turns out, the gauge wasn't broken, I took the numbers with a cold engine, would that maks that much of a difference?

I thought it was supposed to be done with the motor warmed up so the rings seal? I doubt you have good compression with cold rings.

Okay, I'm fixing the timing problem tomorrow and then I check it again after the car warms up.

ive tested mine on cold and warm engine to see if there actually was a difference..there wasn't on mine...got 205 across warm and cold.. :shrug

Originally posted by powellds
Okay, I'm fixing the timing problem tomorrow and then I check it again after the car warms up.

make sure it is hot. Drive the car for about 10 miles with engine braking to ensure everything is tight.

just did a compression test last weak. the first day i did it on a cold engine, and i got 185 on #1 cylinder. but i didnt realize that an adapter from the compression gauge was still in the hole, so i screwed my spark plug into that and crushed it. :wallbash so my mom brought a new plug to school and i didnt get to do any other cylinders. next day i did it and remembered it should be warm, and i got 200-200-210-200 so i would say that being warm made a difference.

Okay, I had some crappy OBX cam gears on my crower 2's and my CEL came on for my IAC motor saying it wasn't reaching the max idle air speed or something like that. If the cams weren't tuned right, that would mean I would have some overlapon the valves and cause the compression ro be low correct? Give me some input here, I think that's right. I'm waiting on my Fidanza gears to get it tuned right and take the test again.

Cams affect dynamic compression. Cams with more overlap will show lower numbers. This is normal behavior.

Also the gauge could be out.

My Dad has a nice BlurPoint gauge and it's 20 P.s.i out :shrug ?

I went to the air compressor and saw 125 at that guage, plugged it into the hose and put pressure through the guage.... it came up 105.

go figure.