Rb26 Comp Test Are These Results Still Ok

[falky929]

are theses resualts allright???? its a r33 rb26

135psi cyl 1

145psi cyl 2

135psi cyl 3

135psi cyl 4

140psi cyl 5

145psi cyl 6

[GTSBoy]

The spread between them is a little larger than you'd like - normally not wanting more than 5 psi between them. That would indicate that perhaps 3 of the cylinders have started to suffer either more ring wear or maybe some changes around the valve seats that the others haven't so much. But really, please elaborate on how the test was done. Was the engine all warmed up? All plugs out? etc etc.

[SECURITY]

It's 5% rather than 5psi. You've got a difference of 10psi where it should be 7-8psi. Nothing major for the moment, just keep in mind for future tunes to tell them to make it safe. Also make sure you religiously change your oil and filter every 4-5000 and buy the good stuff!.

[R32 Driver]

Seems alright to me with only 10 psi difference between them

[gtr fan]

aren't these generally low results anyway. I recall mine were in high 150-low 160psi range when I bought my car.

[GTSBoy]

They are a little low, but plenty of otherwise healthy engines test that low or lower. Which is why I asked how the test was done. Not having it fully warm for example can lead to both low readings and more difference between cylinders.

[ido09s]

If its warm Its is a bit low, and i would expect to see 160psi in each cylinder. I cant say i ever tested one cold so not sure what you would expect to see,

Its already been said but treat it nicely, limit boost pressure and she will be right. I wouldnt go winding 20psi into it and expecting it run 11's as its just not going to happen.

[SiR_RB]

Yeh sounds like a tired engine

Mine got comp tested few months back @ 160psi even across each cylinder

[SECURITY]

Yeh sounds like a tired engine

Mine got comp tested few months back @ 160psi even across each cylinder

160psi across all cylinders? really? is this on a brand new motor?

i rarely see compression tests show over 155psi on all cylinders. the best ive seen has at least a 3psi variance between cylinders.

[SiR_RB]

160-162psi, bought it like that from japan. but alot of the gaskets/and bolts etc are very very new so who knows whats in there

[blue_vl_t]

my rb26 has a 15 psi difference, well it did before i reconditioned the head and put cams in, haven't checked since.

still runs well

Edited July 18, 2011 by blue_vl_t

[RJ06]

My R32 GTR has an R33 RB26 in it, all cylinders were between 165-170 psi engine was warm, full throttle position and all plugs were out.

It is a stock standard engine, bought it from a wrecker with 88000 kms on it.

[GTRsean]

I used to get 150-155psi with stock engine.

260 poncams and a rebuild, it went to 125-130psi.

R32GTR

warm engine, plugs out, throttle open.

No more that 14psi between cylinders is fine, and stock engine compression limit is 128psi, and standard value is 177psi @300RPM.

From service manual.

[ido09s]

260 poncams and a rebuild, it went to 125-130psi.

And cam gears which were not set to 0. Set the cams back to factory and see what happens.... my guess is that your comp will suddenly change for the better

[GTRsean]

I guess the new owner will have to do that . You are right though, they weren't at zero!

[SiR_RB]

yeh very important to have the engine at operating temp and to remove all spark plugs and crank the car while throttle is all the way Open...i even removed my fuel pump fuse too

[DVS JEZ]

disconnecting the CAS is much easier, its stops all spark and injector pulse.

mine was 170psi across all when i bought it.