NROD315

i recently compression tested my b18c in my eg and the results i was was getting were
1 Wet: 210psi
2 Wet: 210psi
3 Wet: 240psi
4 Wet: 240psi
I was wondering why the difference in cylinders. Thank you.

ezone

What results indicated a need for doing a wet compression test?

How about posting the results of a normal DRY compression test, on a hot engine.
Crank it until the gauge quits climbing, plus a few more hits just to make sure it reached its max.

NROD315

my results were around 190-200 psi dry. I had it full throttle and cranked over an even amount of times 4-6 times cranked over

ezone

That would not give me cause to try a wet test.

Are you chasing a running problem or something?


Personally, I crank until I'm positive the gauge is maxxed out and will not go any higher.

I also note cranking RPM and may put a battery charger on so cranking speed stays consistent for all cylinders.

NROD315

im just having all types of issues with my motor so I just want to run tests to start knocking out what could or couldn't be wrong and these are the result I got. Should i not run the test again?

ezone

If you had good compression numbers with a normal test, there is no reason to do a wet test.

emich

You could have slightly bent valves on cylinders 1 and 2

Mad Dog Tannen

That looks like good compression to me. Leave it alone. Valves are not bent!

A little difference between cylinders is fine, the rings and valves do not all wear exactly the same. The valves may not be sealing like new or may be worn a little causing the slight difference. Nothing to worry about.

That is a good test, within service limits!

ezone

My first thought:
Unequal oil distribution for the wet test, more oil went in the last two than the first two.

Excessive oil takes up space in the cylinder, falsely alters the effective compression ratio, and therefore falsely increases the compression test reading.

Tons of carbon buildup in a cylinder or on top of a piston can have the same effect.