Compression Test Results

[wrxhoon]

And yes the 6th cylinder was 150 too (sorry guys).

And yes we did try a "wet test" with a t-spoon of oil and the compression improved. Rings it is. Rebuild away! I am considering a swap with a R33 RB26.

Depending on how much oil you put in, it will always give you more compression ( the chamber will be smaller with a tablespoon of oil). If you put oil in the good cylinders you will get a better ( higher) reding as well.

My guess is you have a busted ringland on number 3 , a leakdown test will confirm though.

[Italiazr1]

well mines screwed i dont know the figures on all cylinders but mechanic said 100 psi on the test

ive got the rb20

Lucky the stupid car yard that sold me the dud has warenty got to rip out my parts though

i would have never know if i didnt start modifiing it i found out cause its not making the right power figures with what i have

[SS8_Gohan]

^ yet ANOTHER reason not to buy an import from a car yard. There are NO good import car yards, everyone is dodgy

[Ph@t-G]

Hey all,

Just want to ask if the following compression rate is normal? I'm just getting in skylines and am looking to get one but don't know too much about the mechanical side of things.

1. 120 2.122

3. 120 4.125

5. 125 6.120

The car is a '90 R32 gtst, RB20, with the only mods being pod and exhaust. Btw what is the normal range for the compression rates or does it depend on variables?

Cheers!

[Rekin]

Hey all,

Just want to ask if the following compression rate is normal? I'm just getting in skylines and am looking to get one but don't know too much about the mechanical side of things.

1. 120 2.122

3. 120 4.125

5. 125 6.120

The car is a '90 R32 gtst, RB20, with the only mods being pod and exhaust. Btw what is the normal range for the compression rates or does it depend on variables?

Cheers!

My R32 had (6months ago):

140, 135, 145, 140, 135, 145

Your numbers are quite low....

[Ph@t-G]

Hey rekin thanks for that.

Now another question that I have - what is the normal range for compression? Is it safe to say it's between 140 to 160?

[EVL15H]

Got mine tested on saturday, every cylinder got 105psi.

i have a 33 gts-t with minor mods and those figures seem VERY low

things is though, its not running rough, doesnt use excess oil, no smoke, cold start is fine.

can anyone help me?

[SS8_Gohan]

seems low, but i'm by no means an expert...

how much did it cost you?

[khunjeng]

nissan manual tells your the values and variances. From memory the variance should be no more than about 12psi.

The lowest number is about 120.

On and RB25..cant rem. exactly though.

[Yme33]

ok so i guess that 130,130,125,130,130,130 is at the limit for a rebuild on a rb25det.

wet test was fine

edit

further inspection shows that comes standard with 9.1psi, think this test sits around 8.9psi so cant complain

Edited May 2, 2007 by Yme33

[lach 32]

hey, got my comp. tested about a month ago.

r32 GTS-T:

1.165

2.160

3.160

4.155

5.160

6.160

[lach 32]

ok so i guess that 130,130,125,130,130,130 is at the limit for a rebuild on a rb25det.

wet test was fine

edit

further inspection shows that comes standard with 9.1psi, think this test sits around 8.9psi so cant complain

from what i know, those results aren't to bad, because there quite even the whole way across.

[Nizmoid]

Tested my comp yesterday

1 135

2 125

3 125

4 125

5 130

6 130

motor rb20det test done at 71degree water temp, 520rpm, fuel pump off, cam timing should be standard but not sure

No. 1 is the one im worried about because the spark plug and piston had oil residue on them

time for a rebuild

[RipNGrip]

165 - 175 rb20det

220XXX kms...... very suprized!

done by the mechanic...........

I performed my own compression test even across!

[Cubes]

Gauges differ.

Cams also differ which influences the 'dynamic' compression ratio. Dynamic compression ratio is what you are seeing with the comp test gauge.

[Hotwire]

Had mine tested when I bought my R33 about a month ago. 140 accross all 6 (+/- 2), so although down a little was very happy there were all even

[SiR_RB]

results will vary depending how you do the test: eg the engine is at opperating temp, and throttle body wide open, or if the engine is cold etc etc

140 across each pot is good, at least there all even results

[BNR32t]

No problem in this engine, RB26 138,140,15,140,138,140 Thinking rebuild.

[RBwhatever]

The skyline engine manual specify 170psi + or - 5psi for the RB25

[Guilt-Toy]

my cold fully forged rb30det runs 95psi in each cyl when cold and 120 each cyl when warm.

engine has done 15000km's and showed these readings from the start. (Low compression for big boost)