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Pretty sure if the shell had spun you would see score markings - so sounds like this is not like the failures seen on the 2.7 but something different has happened.Quote:
Originally Posted by martinfrench
What spec oil were you running?
I suspect you won’t land on a definitive reason why it failed, can only speculate now.
No I didn't.Quote:
Originally Posted by 350RRC
I started to try get an estimate on the mains (mainly because the manual doesn't specify a tightening torque) but I gave up after having issues with my torque wrench.
You can see in the photo that there is 'some' score/friction marks there on the adjacent main. I'll take a measurement when I get home tonight and see if there's any wear. I doubt there will be much. But again, symptom or cause?Quote:
Originally Posted by DiscoDB
Penrite 5W30. Although I had it at an indi recently (3-4 months back) for a oil cooler/rear timing belt change and I'm not sure what they put in it.
You will be looking for scoring on the back of the main bearing shell and the housing. This will tell you if it has rotated at any stage and blocked the oil flow to the big ends.Quote:
Originally Posted by martinfrench
Can they rotate and return to the correct position? - possible but unlikely and now speculating. If the main had rotated I would have expected you would have found this during the strip down.
There are so many unknowns - including if you are not the original owner what it’s prior history was. Damage could have been done some time ago and only now worn enough to fail.
Could also be a manufacturing / assembly defect - such as wrong size bearings fitted to the big ends with too much clearance, again shortening life and only now failing.
I guess the real question now is - so what is next? Does this D4 get to run again?
0.5 = .020" which is ok but not "desirable" so to speak.Quote:
Originally Posted by martinfrench
I've seen plenty of engines down to .020" on the mains and big ends, but in a perfect world I guess you'll go with a new crank?
And you can get 0.5mm undersized main and big-end bearings for the TDV6.Quote:
Originally Posted by Discodicky
If re-using, I would get the crankshaft crack tested as well to make sure there is not another pre-existing condition waiting to go snap!
LR Time has detailed data and parts info now after their YouTube rebuild. If you emailed them I’m sure they would share the info.
The cranks are hardened to a certain depth from memory.Quote:
Originally Posted by Discodicky
It's in the LR Time vids...........maybe #3 of the TDV6 rebuild.
He ended up using a different S/H crank anyway.
DL
20 years ago we’d stress relieve, weld up the journal, shotpeen/linish the non-machined areas, re-harden the journal and then nitride the whole thing for good measure. Jobs a good-un.
Edit : maybe 30 years… time slips by.
anther you tube thread from a pom called piston broke, he has some good stuff but the German chap in LR time is very methodical and logical in his approach. His Mrs is a cute one - Vera "Oh my God" she says at everything. Too funny.
