Crankshaft Whip

[T04GTR]

interesting.

lets see. dammaged main bearings. lets see the photos.

also lets see the crankshaft in question. has it been grub screwed? or just linnished prior to assembly.

did you have arp studs in the mains? if so was it linebored?

did you use arp head studs? if so was it torque plate honed?

what was the end float of the crank once installed?

what was the bearing clearances of the mains?

having blocked pick up? had it done 300000kms or had no oil changes?

what was your oil pressure like. on cold start, hot idle, hot >5000rpm. (with a non standard acurate guage)

i would like to see the oil pump. if its dammaged, youve overreved it.

the ONLY things the ware out mains and they are not auidable are: bent crank,to tight oil clearance,incorrect thrust. ie to tight. and 99.9% of the time its shit in the oil.

sounds to me the only thing that killed your engine is shit in the oil. if all the other bearings are ok. like the bigends have no scratches on them, then its definatly shit in the engine.

oil starvation starts at both ends of the crank. ie: 1 and 6 are the worst. 3 and 4 are the best. its the opposite for oil contamination.

check all the bearings all laid out in order. for an engineer to say "bore wash" is an absolut load of shit and will be thrown out. besides its a non standard engine and reqires more oil changes. ive had my oil so wet with fuel it was like water and no bearings were scuffed after it was pulled down 50,000k later....

dirty engine rooms and not cleaning out crank and block galleries is what kills engine beaings early.

[T04GTR]

just my 2c on failures i have seen.

[SECURITY]

the motor had around 12,000km's since the rebuild with all 3 oil changes from run in completed at the right intervals. i.e. mineral oil @ 0km (i was told), 500km and 1000km, then motul turbolight 8100 at 1500km then @ every 3000km interval thereafter.

it wasnt my job to check if the oil pump was shagged before it was installed so i dont know if it was good to go, if it wasnt im sure i would've been notified.

i didnt have an aftermarket oil pressure gauge so i dont know what it was like, and i cant go off the standard one because it stopped being reliable around a year ago. when i picked up the car i was told by the owner of the business that "oil pressure was off the charts".

i dont have any other info for you.

Edited January 2, 2009 by SECURITY

[Adriano]

Or overly tight thrust clearances, which is common when assembling rb's

[Risking]

I just read your first post and you say that the thrust bearing has worn??

Is this meaning the actual thrust faces are worn or the slipper surface is worn??

If its the slipper surface then Dave is correct and the oil was probably contaminated. How it got contaminated could be due to oil surge and the far end bearings leaving deposits in the oil perhaps.

However if its the thrust faces that are worn, I have seen a few other engines recently at my machinists that have done similar things, over adjusting of the clutch seems to put constant load onto the thrust bearing faces which causes them to rapidly wear away. Especially if your using a very heavy clutch.

[SECURITY]

not too sure which surface has worn and my car is auto.

[Kinks]

I'm far from an expert but to try and answer your earlier question on how "incomplete combustion" can occur if your AFRs are correct, the only thing I can think of is that with insufficient ring tension you may have been getting oil into the cylinders which wouldn't burn completely. What was your oil consumption like at each service?

[2rismo]

I'm far from an expert but to try and answer your earlier question on how "incomplete combustion" can occur if your AFRs are correct, the only thing I can think of is that with insufficient ring tension you may have been getting oil into the cylinders which wouldn't burn completely. What was your oil consumption like at each service?

Completeness of combustion and stoich AFR's can be wildly dissimilar. Checking AFR's against plugs is more accurate but unless you have a 4 or 5 gas analyser and the know-how to interpret the readings, you're pissing into the wind as far as determining combustion efficiency is concerned.

I can post some really heavy reading on the subject if you like (not my own work) but it's not really for this thread. The super-short version is that the opposite to the way you imagine combstion being completed can and does happen and it throws the mixtures out accordingly.

[SLAPS]

It pays to get the lot line bored for peace of mind too, i usually line bore the whole lot and grind the crank to get my clearances spot on, so far not one issue with any of them (touch wood). It makes the bill longer and bigger though

Excellent advice.

I had my RB30DET line bored when it was built up back in 2004.

4 years later and 100,000km's often hitting its 7300rpm limiter its still holding together.

Std rods, forged pistons and King Bi-metal bearings + all the little bits you do the bottom end set me back a shade under 4k.

I found some of the 'performance' workshops the be the slackest of all.

I ended up having the motor built by the enthusiastic blokes down at City Dismantlers.

They had heaps of time for me asking questions and what not.

They knew what had to be done to the bottom ends of the rb30 to make them hold together at high rev's.

Importantly they stuck to the quote (once the motor had been inspected) and time frame.

Just under 3 weeks from drop off to pickup with the motor all strapped to a crate and wrapped in plastic.

All the spare/left over parts were bubble wrapped and placed in to a box.

Extremely organised.

Edited January 3, 2009 by TheRogue

[Kinks]

I can post some really heavy reading on the subject if you like (not my own work) but it's not really for this thread. The super-short version is that the opposite to the way you imagine combstion being completed can and does happen and it throws the mixtures out accordingly.

I'd be interested in reading it if you can PM it to me

BTW Joe it was interesting to read that written report, since you gave him a good rap. I noticed in his header he's in Forestville, I grew up not far from there. Might be handy to know one day!!