Rb25Det Compression Results

[jSbr0]

Got a 32 with a rb25det series 2 with unknown k's on the motor i so decided to check the compression I first tried the screw in type connection which was hard to do up tight and gave me 90 So i tried the push in type and got 120-122-121-120-123-120 Then engine was hot These seems to be low results but how low is to low? The car runs fine and pulls hard

[Ad's]

Should really search:

http://www.skylinesaustralia.com/forums/topic/407717-compression-test-results/

Pretty sure providing the cylinders are with in a % of each other no matter how low to an extent it's fine. From memory its something like 5% but i could be wrong.

[jSbr0]

Thanks after looking at that thread I didn't have the throttle body open whoops suppose it does matter

[jSbr0]

Ok tried it again with throttle open got 120 120 120 120 110 110 battery going in the end maybe ? Very odd results this time

[boostn0199]

Aslong as there all within the 5percent its generally alright as other variables an effect the actual number of the readout just mainly looking for really low numbers when theres a problem.

[jSbr0]

So if I had like 80 on 1 or something like that I would be in trouble I just find it strange how the second test gave even numbers might try a different tester

Edited March 17, 2013 by jSbr0

[daineisdabomb]

Thats very low. Im pretty sure the manual says the usable range is 180-130psi. So u may need a rebuild or at least new rings

[daineisdabomb]

The manual says the usable range is 180-130psi. So looks like shes a bit low and may need a rebuild in the near future

[AngryRB]

Got a 32 with a rb25det series 2 with unknown k's on the motor i so decided to check the compression I first tried the screw in type connection which was hard to do up tight and gave me 90 So i tried the push in type and got 120-122-121-120-123-120 Then engine was hot These seems to be low results but how low is to low? The car runs fine and pulls hard

Don't forget if you've got a set of cams in there it could give you a low result too, id check the timing isn't out too.

[boostn0199]

did u do the test cold or hot engine?

[jSbr0]

The engine was hot did it straight after a 45 min drive I did read somewhere you take out all the spark plugs when doing the test hmm.. A friend mentioned to use a battery pack to help with cranking incase the battery is not %100 Ill check out the cams I also have a consult cable so I'd say I can check out the timing with this?

[KiwiRS4T]

Those compressions are fine - not ideal but you could get another 200,000 out of it so don't go pulling it down unnecessarily.

[Simonmac]

as long it is within a 5% average it is ok. like said before as long as they are all within 5% of each other it will be ok

[Guilt-Toy]

even 10% is ok