compression test

[saff_cossie]

Hi all

I have a found a skyline that I like but want to get a compression test done it before I get it. Can anyone tell me the readings that it should give back so I know if it is decent please?

The car is a 1995 Series 1.5 R33 GTST which is as far as I can see, standard.

Thanks in advance

[Dragon18]

Hay dude not to sure what the compression ratios on the skyline are but i know that most normal cars. come out of factory at like between 150 to 160 psi depending on engine capacity etc.

I know with SR20 180sx anywhere over 140psi is good

but the important thing to take not on compression is that they are all similar.

e.g

140 139 140 142

its bad to have inconsitancy in cylinders

e.g

135 140 145 129

just as an example some one please correct me if iam wrong.

hope that helps you out

[maverick]

140psi with a variance of less than 15% is considered good. consistency being more important than the compression value as the compression value does vary according to a number of factors (where it's done, altitude, air temp...). try to make sure the values are a close as possible. The closer they are the lower the risk of your engine blowing up or something.

[DivHunter]

what does a higher or lower pressure reading mean in terms of engine wear/possible problems?

[pinoi_boi_r33]

i have heard a leak down test is a better indication.

[4door_Sleeper]

Do both a compressiontest and a Leak down test. (also known as a wet and dry compression test)

The leakdown test will indicate the condition of the head (because the oil should help seal the rings) and the difference between the two will give an indication of the cylinder and rings.

[saff_cossie]

Thanks for the replies guys. Just jumped online today. Currently in the UK and not had Internet access for a few days. I will make a note of those figures back in oz and take them to the test with me.

Many thanks for the replies though.