Broken Crankshaft Count?
- Thread starter EDP
- Start date
Yeah but its pretty involved. Pulling motor is Easier IMO so you can flip it upside down so lifters drop down (up technically)
Just broke the crank in my built LBZ. 35k miles on build. Socal 6460 standard firing order cam, stock crank that was magnafluxed, polished, balanced, and keyed. Socal balancer. 664hp.
Man I hate to hear that. Really makes me second guess some of my upgrades in the near future
I just did it in the truck, just buy 16 magnets! Lol! Sucks that they arnt like every other chevy on the plannet, spin and pray!!
It does suck pretty bad, but atleast I was only a few miles from home. Stock lmm engine going in tomorrow, and rebuilding my original engine again.
Sorry to hear
Curious as to why you didn't go with an af cam?
Was it available at the time of your build?
Good luck with your new engine!
It was available, but I had to get it done quick and there was a decent wait time on af cams at the time. Also kind of limited on funds at the time. Just got a stock short block in it last night and got it running, but have a coolant leak to figure out. Going to take my time rebuilding the broken one this time.
It was the original crank that was in the engine. Had it mag'd, polished, balanced, and keyed.
Found this awhile back regarding the what to do with the Duramax crank when doing the above, see the link in post #2
http://www.duramaxdiesels.com/forum/showthread.php?t=60967
Page 8
http://www.sbintl.com/tech_library/articles/rebuilding_the_6.6L_duramax_diesel.pdf
https://www.google.com/search?num=1...21.0....0...1c.1.64.hp..0.25.2065.dvE4MLm055Q
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Well, that is very interesting. I did not have that done to mine. I still think it's mostly the firing order that breaks them, but this is something new to me. Didn't even think about nitride or cryo treating it. Maybe thats why it only lasted 35k miles after the build.
A small shop in Dansville, NY. The guy does a great job building engines. I don't think it's his fault at all that it broke.
Nitriding and Cryo are surface treatments for wear, not strength... My personal conclusion to this broken crank epidemic is to small of a Fillet on the crank journals or the journals are just to small IMOP. The factures are bending fatigue, meaning lots of flex. I think the firing order change is helping but they are still breaking with an Alt. fire as Shane P. demonstrated. I would like to know if the new Wagler crank have a larger fillet radius?
I still wonder about shot peening the fillet radius as to break up areas for the cracks to originate... Has anyone really tired this and had a failure?
I still wonder about shot peening the fillet radius as to break up areas for the cracks to originate... Has anyone really tired this and had a failure?
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It's definitely related to the filet to my understanding, that is where the Winberg crank comes in that Wade and Wagler use...the Aluminum Hemi rods have a smaller diameter rod journal to my understanding, but the rods are narrower and use a narrower bearing, the have a much better filet and stronger rod journal... I do not know of any broken Winberg cranks with that rod combo.
Any broken billet crank I've heard of was built as a replica to OEM crank specs out of what I would expect to be best materials and processes on the market, leading me to believe it is a filet and journal problem...
All just my opinion
Any broken billet crank I've heard of was built as a replica to OEM crank specs out of what I would expect to be best materials and processes on the market, leading me to believe it is a filet and journal problem...
All just my opinion
Not correct. Nitriding toughens the surface reducing the origination of a crack on the surface.
Cryo is a parts treatment that stress relieves the whole part without impacting it's heat treated properties. Especially good for heavily machined parts or parts with odd mass properties that would develop internal stresses from heat treatment.
Both address specific failure modes and are not exclusive to each other.
what good would that number do? There are millions of these trucks out there. This thread is to break down who has actually broken a crank and specify what year it is to see a pattern.