compression numbers

And why did you do a compression test?
What were you looking to determine?
A BHG? Checking for ring/piston wear? Valve wear?

What are you trying to find with your test?

If you were looking to see if you have a BHG (which you did not state), you picked the wrong test/way of diagnosing. You did mention however, that you think the results mean that you don't have one.

Everyone on SF thinks that a compression test is your best answer in seeing if you have a BHG -- it only is if the HG is long gone.

BTW, I know that a CPS is for turbo motors, some may not have picked up on that (that it is a turbo, because you did not mention it).
In that case you are supposed to have about 142lb/in according to the TSRM.

EDIT:

And here is the TSRM on that:
http://www.cygnusx1.net/supra/library/TSRM/em/EM_21.html

EDIT AGAIN: you got a PM from me on additional info.

i bought a car with a high mileage motor and i wanted to see how good the compression was in each cylinder, that was the purpose. i wasn't trying to determine if i have a blown head gasket. i was really checking to determine if i should rebuild, or if i can push this motor a little bit with tuning off course. and i have considered redoing the hg because i can't trust the work done by the previous owner. but if i do the hg again it's already got 140k and at that point i thought that i would just get a low mileage motor or build a motor with forged, p&p etc. i was simply checking to see if i could abuse this motor a little bit in it's current state.

Gotcha, see the thing is, many people as I keep reading, think that a compression test is the way to see if you have a BHG. My car had a BGH and the numbers came out fine. Compression tests don't show BHG's in their beginning stages -- when you should know about them, not later on.

Also, the thing I don't like about compression tests is that you get numbers, but not necessarily know what they mean sometimes. You could have a small leak/wear (not necessarily only a BHG type leak, but also another type) that will decrease your pressure; but then have some carbon build-up that will increase your pressure. So you can have two problems making you think you have a healthy engine, when you really don't. I had such an experience.

A leak down test is a better test many times for assessing an engine, and you will see/hear/feel where you are leaking.

BHG testing (coolant to water jacket type): get a block tester -- if you have already checked for the other possible problems that can cause overheating/coolant loss.

If you wanted further analysis with a compression test, do a wet/dry compression test. You already have the dry numbers, get the wet ones (with oil put in the cylinders).

Btw, my car was high mileage, if you consider it that at 143kmis, and everything was great in the motor (very little wear on anything as I measured the clearances), just the BHG was the problem. So if taken care of, 140kmis is not that much.

thanks for the feedback. the only reason i origionally mentioned about a bhg is i figured some might seee the difference in compression #'s and get some ideas. i wanted to let them know that this test was not for diagnosing a bhg beacause it's not there, but merely to see the condition of the engine. i want this to be a reliable car that i can drag and autocross, i'll probably end up building a motor anyways.

you have good suggestions; i will do a wet test and a leakdown test as well as all preventive maintenance possible on this motor/drivetrain before attempting to turn of the boost and go.

Looks like you have some good ideas then as far as wanting to make sure it is healthy before turning up the boost and so on.

As far as the variations you got so far, there can be a lot of reasons.
Maybe you have carbon build-up on the high cylinders; the power of the battery can also have an effect (if it is weak) and give an overall low reading for all, I'm sure there are other reasons that can also give an off reading. If you wanted to do a leak down test, it is linked within my write-up.

Thanks for the compliments and good luck.

As far as the second half of your first post, I haven't a clue. Maybe someone else can help on that part.