R33 GTS-T Compression Test values.

[tenzero]

A small question for the wise and experienced of you out there.

It looks as if I have finally found a tidy Skyline to be my new wheels.

As I am new to turbo engines, I have tried to listen to all of the wise words spoken on here.

I am going to arrange a compression test before parting with my cash. Can anyone tell me what sort of compression numbers a stock R33 GTS-T engine from 94 should produce??

I realise they should all ideally be the same or very close to each other, but as a guide can anyone tell me what values I should see??

Cheers.

D.

[adam 32]

should all be around the 150 mark

[MrMayhem]

higher

[tenzero]

Thanks adam!

How much higher MrMayhem??

[VSPECII]

varies from each guage but 175 -220 is good but the best way to tell is doing a cylinder leakage test. Bit of stuffing around though

[MrMayhem]

will be same as rb30e

[tenzero]

Interesting, thanks for the advice.

[adam 32]

higher?

they are around the 150 mark for RB20DET, SR20DET, and RB30ET engines...

[MrMayhem]

SR and RB20 are 8.5:1 static comp ratio

RB30et is 7.8:1

where as the 25 and 30 na are 9:1

[adam 32]

ah right

so were talking more around the 170-180 mark then?

[Neo]

Units = MPa/rpm

RB25DE

Standard Value - 1.26/300

Limit Value - 0.96/300

RB25DET

Standard Value - 1.20/300

Limit Value- 0.90/300

RB26DETT

Standard Value - 1.18/300

Limit Value - 0.88/300

Varience limit between cylinders - 0.10/300 all above angines.

* Values from the Nissan Service Manual.

[tenzero]

Outstanding Neo, thanks for this.

So doing the numbers I should be aiming for 171 psi with a fluctuation around 14.2 psi at worst between the cylinders.

[Gav]

Whilst I've got the coil packs and assembly out anyway, I may check compression.

Can you hire compression testers in Perth?

[adam 32]

oxford spares used to hire them out

or cromlins i think it is

or if u go into ultra tune they charge basically nothing for a comp test

[gtrken]

Get a cylinder leakage test.

Will give a better indication of engine cond.

Have had an engine recently that had acceptable compression variance but the leakage was up to 70% on 2 cylinders.

cheers

ken

[adam 32]

how does a cylinder leakage test differ from the std compression test?

[red17]

As far as i understand it, it involves pumping compressed air into each cylinder at TDC and measuring the amount of air thats bled off as a result of leakage through either piston rings, valves or head gasket. This provides a true full load compression test and can more accurately guage ring wear in particular.

Red17

[adam 32]

ah right

thanks

[GTS-t VSPEC]

Hmm, think I better get that done to mine:D

[RB20LagWagon]

Nah paul just boost it till it blows