cold compression test question

[FORMONTOYA]

ok...doing a turbo swap and after removal of the exhaust mani i found that i need to yank the head for a freshen' up (#2 & 3 exhaust port is coated in oil, bla, bla, bla...). so before i remove the head i want to get an idea of how the bottom end is holding up. ran strong until the turbo took a dive...but hindsight is 20/20...and after a few searches through various forums, the head has probably been going out for about 4+ months before the turbo dumped (used to the old v8...exhaust would have looked worse w/bad seals, does the turbo mask this a little...humm). anyway i want to do a compression check...


1) how important is it to have the car totally warmed up? car is up on 4 jackstands now w/exhaust mani setting on garage floor.

2) are there any cold numbers that i should hit, or a percentage to add since it is cold (cold rings should give a lower number...and get better when warmed up...right?)? i do not want to fire it up w/no exhaust mani. and would have to do a lot of work just to get it drivable again...to just turn around and tear it apart right after.

3) what are my options?

doing a search revealed this site:

http://www.geocities.com/dsmgrrrl/FAQs/compression.htm


thanks,


jim

 

[98GSX_MTX]

You will get no idea of how the bottom end is holding up with a worn out head. The pressure will leak out of the head.

It is very rare to have a fairly good running DSM with crappy rings. Normally the head or head gasket is weakest link. Once you have the head off you will be able to check the condition of the cyl walls and that should tell you all you need to know.

A cold compression test probably wont be much different than a hot test.

 

[FORMONTOYA]

thank you,


jim