compression number, what do yo u think

[95talontsi]

I just comp checked my motor, it was cold, and got about 125, 123, 127, 123 bascailly all just around the 125 mark. Is the motor worth adding the bolt ons?

 

[insane147]

its way low.....im sure 145 is the limit. i usually get 185 across.

 

[quest49s]

What altitude are you at? altitude can have an effect on compression readings. Also, when you did the comp. test did you have the throttle open and the mpi fuse pulled out.

 

[candela]

Regardless of any of that your compression souldnt be that low. That is low for a 1g, and shoudl be rebuild time for a 2g.

 

[95talontsi]

#### !!!!!!!

 

[larryd]

he said the car was cold.. you arent supposed to do a compression test on a cold engine, there is a big diff between compression on cold and warm engines.

 

[LaserRST]

Ditto on the cold engine. It needs to be at operating temp... but the difference wont help your numbers enough. The service limit is 122 on a 1g and more on a 2g since it has a higher compression ratio. Warm the engine take out all the spark plugs, and give it a good three or four turns, then try some oil in the cylinders. If you plan on modding a good rebuild might be in order... how many miles on the engine?

 

[95talontsi]

Alright I gave the engine a warm up, and I got around from 127-125-127-130. But I have an early 95, 94 production, I bought it off an ex- auto'xer was really knowledgeable, said something about 1st gen internals or 1st gen block.

Another thing I took the numbers to my boss (mechanic), who builds race cars, chevy's of course and said they look pretty good.
Any other input.

 

[larryd]

wow.. same #s after warmup huh..

 

[candela]

Yes I have heard of the early early 95's still having had the 1G blocks which would mean yu have 7:8 compression. Eitehr way 1G or 2G block, the compression is still pretty dang low dude. Service limit is 122 psi for a 1G, but you wont gain much in performance as you would if you rebuild it. A properly sealingm motor will be improvement enough over what you have now...