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* I thought I would be clever and save some cash by putting in Unleaded fuel with a bottle of octain boost that I had left over from when I drove her back to Darwin from QLD in March. I used this method once on the trip back but only cause I had no choice, and nothing went wrong then. I am kicking myself over this, you don't need to say anything... but getting paid monthly sucks ass

I think you will find this is what caused your problem. 91RON fuel with octane booster that maybe boosted it by 1RON to a total of 92RON, with some thrashing added in on an ECU that was probably tuned for 98RON. Its a recipee for detonation, which in turn killed your piston(s). Have seen similar detonation damage on a GTR, I think it was 3 cylinders down to 20psi on compression and the car wouldnt start.

Get a compression test done, but its probably rebuild time. A realistic price, with some nice internals (you may as well for that power level), up to $5000 including labour.

if your dipstick was blown out then don't f**k around trying to diagnose it mate. Start pulling the motor out. You've got some serious blowby.

If you need closure, do a compression test.

I bet you have a couple of completely stuffed ring lands..

if your dipstick was blown out then don't f**k around trying to diagnose it mate. Start pulling the motor out. You've got some serious blowby.

If you need closure, do a compression test.

I bet you have a couple of completely stuffed ring lands..

mate i just finishd pulling down a rb25det with reasonably low compression, nothing a 150k km motor wouldnt expect. i got the pistons out, and numbers 2,3,4 and 5 were obliterated. the ring lands literally fell on the ground. do a compression test, as ive seen this sort of thing before, and it was actually the head gasket blown between the oil line to the head and cyl 3.... its not ALLWAYS rings........

  • 2 weeks later...

I'll dig up of an old thread..

What did you end up doing with the motor?

My bet is on the usual ring lands due to detonation.

Without labour my bottom end with forgy's cost me $3.7k, it was a little on the cheaper side for what I got as we had 2 motors done at the same time so worked out a nicer price.

  • 1 month later...

She is still getting done at the moment. I am taking my time. 2 months off the road and counting. Still haven't ordered parts yet but I expect themt o come to around 4k. I am getting the head and bottom end done so the motor is good for around 600hp at the fly.

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