420A 420a DOHC Compression test results

[91-talon-tsi]

I have performed a compression test on the 420a DOHC engine in my 1996 Mitsubishi Eclipse RS and the results are as follows :

DRY TEST :

CYL 1- 150 PSI
CYL 2- 145 PSI
CYL 3- 150 PSI
CYL 4- 150 PSI

WET TEST :

CYL 1- 175 PSI
CYL 2- 160 PSI
CYL 3- 160 PSI
CYL 4- 175 PSI

The engine runs good and does not seem to use any oil since I have acquired the car. The previous owners said that the engine burned a small amount of oil. But, I changed the oil and have put about 1000 miles on it since I changed it and the oil level is still full. The engine does not smoke and does not appear to have any leaks.

It appears that the engine does in fact have the revised MLS headgasket as I can see a metal tab sticking between the cylinder head and the block. The tab has 2 small holes in it's center between cylinder 2 and cylinder 3, and 1 small hole on the outer edges near cylinder 1 and cylinder 4. I assume this is the correct MLS head gasket.

My question is are these compression test results acceptable ?

 

[PotatoFlakeSTi]

Generally variance between the cylinders at less than 10% is acceptable.

 

[19Eclipse90]

Slightly low, but acceptable.

http://www.dsmtuners.com/forums/newbie-forum/388128-what-compression-numbers.html#post152409668

 

[91-talon-tsi]

Ok, cool. Thanks ! I was worried because somebody told me that the service limit was 170 psi, but according to the info on other posts here and info that google brings up, the service limit for the 420a is 100 psi.

 

[nated420]

Umm if you have a n/t then those are not good numbers those are bad! They would be ok if it was a turbo but still not great. You want atleast 180+