Rb25 Failure..

[aphid]

hey guys,

cut a long story short i was cruising along the highway late at night last week by myself, decided to feed the old girl a little boost, suddenly a loud grinding sound, at first i thought it was my drivers side front shock gone to hell as it's been on it's way out for the last month, and was causing the wheel to rub, then i realised it was having an effect on actual engine performance so instantly i jumped on the brakes and pulled off to the side of the road and when i reached a safe speed immidiatly shut of the engine starting to think that i may have shattered the turbo..

at the time i would've been doing around 5000rpm in 4th gear and been at full boost which would've been around 10 - 11psi for me.. i finally finished pulling off the head thisevening and low and behold cylinder #6 has disintegrated in a big way, about 2/3 of the top of the piston was sort of wedged in the cylinder on an angle at the top, not very hard, the other 1/3 of it i fished out from the sump by hand through the cylinder bore, the conrod is nowhere to be seen and there are a few holes chewed out of the bottom of the bore and it is dented deeply all around..

i'm thinking that it would cause a little more than leening out and a big ping for a breakage such as this to happen.. the engine hasn't had a particuly hard life, never raced on the track or anything and the oil is always changed with top of the line motul oil every 5000 k's.. curious as to what peoples oppinions on this failure are?

cheers guys

oh i'll endevour to get photo's tomorrow and the car has 102,xxx km's on it.. who knows what it actually might it was purchised directly from a dealer who imports them by the dozen and we all know how they enjoy winding back the km's..

[FATGTS-R]

I would say the bearing has grabbed and as a result spat the rod.

Possibly due to a dead/dying oil pump.

[tridentt150v]

You've thrown a rod, now whether it was the piston grabbing in the bore and the conrod tearing the little end out of it and then flogging around in the bore, or the big end seizing on the crank and making the conrod revolve around the crank instead of stroking in the bore - you will never know until you pull it apart and check.

If its the first option, it happens sometimes, lean tune maybe, faulty piston who knows. Sometimes the piston will separate at the crown.

If its the second, you have blocked oil galleries to the positive feed or the oil pump is shagged.

Beaten by fatgtsr!

[MBS206]

Either way, most likely the block is destroyed beyond reuse.

[aphid]

yeah, unless i get it bored then sleaved, but i'm more looking at going down the 3 litre bottom end route, the head valves are all in good condition thank god

[sinistaGTR]

what sorta mods you have, and yes its time for the fun lol forgies and big power welcome lol

[aphid]

haha yeah that's the plan mate, as for mods that could contribute, i'm running a power FC (it was only on it's stock map, as it mysteriously dropped it's other one :@), HKS EVC @ .74 bar, a sub zero 600x300x90mm intercooler with just jap style piping and a turbosmart bov.. thinking the stock map on the power fc could've contributed to a lean out as the air was pretty cool that night.. my coilpacks did give off the occasional misfire too when the temperature really dropped..

ahh well, all a chance to upgrade i'm not too fussed, i do think i'll check out the oil pump though and pull the block right down this weekend when i get it out

what sorta mods you have, and yes its time for the fun lol forgies and big power welcome lol

[Cubes]

Grab a cheap rb30 wrecker motor thats running for $150 odd and throw it under the head.

Then grab another and build it up or sort your rb25 out with some nice internals.

Cheap way to get it back on the road and see if the rb30 is really what you want.