R34 Gt-t Compression Results... Opinions Please

[Tours]

hey sau.

had a compression test done an 1998 r34 gts-t today with the following results.

Test was done at running temp with throtle fully engaged.

DRY

1. 187.44

2. 187.44

3. 186.02

4. 173.24

5. 184.60

6. 176.08

Then a few of the varying cylinders were done with a wet test.

WET

1. 214

4. 199

6. 213

These results seem very high ?

I have had mixed opinions about the results of this test.

If anyone from SAU please give me their opinion that would be greatly appreciated. ie Engine Health.

Thanks.

Tours

Edited June 13, 2007 by Tours

[monga]

consistant results over all cylinders would be more accurate to define a healthy engine, ie all 170-175 or 180-185, cylinder 4 might be of concern. But having a varience from the highest to lowest of less than 10% is acceptable I think

[limpus]

Seems pretty decent to me...10% variation is acceptable when it comes to comp tests...so looking at those results the variation is within acceptable limits...who did the comp test? Did you test 4 & 6 again to make sure those readings were consistant? Sometimes you might not get a proper seal when you screw the gauge in and that gives lower readings...

Why do you say the results are high? Rb25s have slightly higher comp ratios so that seems fine as well...

Edited June 13, 2007 by limpus

[Tours]

thanks for the replies.

SHould i be concerned abnout the 36 psi increase with the wet test ?

Any more opinions.

Tours.

[limpus]

A wet test usually will give higher results...it seems that all the cylinders have given a higher comp reading in this case...cylinder 4 seems to have a slightly higher result which might indicate alittle more ring wear than the other cylinders...but defninitely not enough to be of concern in my opinion...i was always told that anything around 30-40psi increase (depending on the test gauge) is normal for a wet test on a relatively healthy engine...i could be wrong though...i guess you have to remember that it is a used car after all...and since you said its a 98 model means that its about 9 years old...rings will wear eventually...good luck...

[Tours]

A wet test usually will give higher results...it seems that all the cylinders have given a higher comp reading in this case...cylinder 4 seems to have a slightly higher result which might indicate alittle more ring wear than the other cylinders...but defninitely not enough to be of concern in my opinion...i was always told that anything around 30-40psi increase (depending on the test gauge) is normal for a wet test on a relatively healthy engine...i could be wrong though...i guess you have to remember that it is a used car after all...and since you said its a 98 model means that its about 9 years old...rings will wear eventually...good luck...

thanks for the info.

Hoping to find something a bit healthier i think.

I mean my car i just sold has 120,000km and when tested had 160 + 1 or 2 right across.

And the wet test jumped evenly up to 170 - 180 Across from memory.

And that was 14 Years Old.

Anymore opinions would be good.

regards,

Tours.

[limpus]

Wow...are you serious? thats pretty damn decent for a older motor...