Rb25Det Compression Test With Motor Out?

[toy515]

Hey guys

I have a long motor rb25 no intake or turbo side and I'm wanting to do a compression test on it the motor is obviously out of the car

Just wondering what's the best way to get the best reading

Do I put oil down the cylinder?

Will readings be lower out of the car?

Any things I need to do different?

[portaz]

Ok I have done this a few times and it will give u a guide only, best way is leak down test but you can do a comp test turning by hand with all plugs out , u get tired easy and I find the first two jumps are what u should look at And I managed 100 psi by hand , just remember that on the starter ur turns at a few hundred rpm by hand it's like 4 and there really isn't any other way around it but like I said it gives u a guide. Once the engine is in I comp test before starting and so far it has worked out ok.

Scott

[toy515]

So getting 100psi by hand is fine? I done it today and could only get 100 by hand across the board

[dori33]

Ive comp tested heaps of motors out of the car (with no manifolds either) . Bolt a gearbox to it, bolt the starter motor on and connect directly to battery. Even an auto box n starter should work

[portaz]

Well if they are all even in my experience is fine that's how I tested my current 26 and did a test on the starter today and they were all 175 across all 6