Added one more to the list for LBZ/LMM. Had to get a new one, found a crack during my motor build so she was all but snapped. I gues thats prob why my #2main spun 
Broken Crankshaft Count?
- Thread starter EDP
- Start date
My neighbor broke one on a bone stock LMM at 99K. It was a C&C with a 4 or 500 gal tank on it loaded daily. He got a new engine for the $100 deductable, no questions asked. He had just paid me for an EFI Live license, luckily we hadn't tuned it yet.
Had two this year. One cracked LLY between number two rod and number two main then a LBZ broken between number one rod and one main. LBZ was 920hp and LLY was probably around 950hp.
Never had a broken crank, but is the main cause the small pin that holds the dampner in place. To small it shears and causes the dampner to spin freely? Or are there more issues?
Add to the list , pulled a lmm out of a kodiac , Broke crank at same spot
Built motor , duel fuelers , 60's overs , gtx4202r
Built motor , duel fuelers , 60's overs , gtx4202r
Most blocks are trashed after this as far as using the oe cap . It can be reused in some cases by using billet mains to fix the damaged area. I guess there are few exceptions but I would definitely check the register of the caps and the line bore before just slapping a crank back in . IMHO
Built motor , duel fuelers , 60's overs , gtx4202r
Built motor , duel fuelers , 60's overs , gtx4202r
I assumed built motor ment billet caps. The reason I asked is I broke a crank 5 years ago and never asked builder if line boar was out. Now I am playing with a bigger fire and distorting blocks quickly, even bent billet rods but no broken crank. Just curious.
I don't think everyone uses billet caps when building a motor .
Built motor , duel fuelers , 60's overs , gtx4202r
Built motor , duel fuelers , 60's overs , gtx4202r
I ran out of money and didnt line bore or anything. Just "plopped" the donor engine crank in there and its held up. So far..
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Did you even check to see if the cap registered in the block correctly ? If not you might have some cap walk and /or bearing failure before it's over?
Built motor , duel fuelers , 60's overs , gtx4202r
Yeah , plastigage would tell you nothing about what I am talking about . Hey if you got that kinda luck , more power to ya !! Lol
Built motor , duel fuelers , 60's overs , gtx4202r
Didnt check that i guess. Im sure you know a lot more than i do. First engine build. If it f's something up at least i learned something and i make decent money now so i can build one this time lol. lil over 15k since crank swap
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super diesel
<<<< Under Pressure
I was one of the lucky ones to catch it before it broke. It's been 2+ year's since I spun the #2 main and had to replace the crank and block (crank was spinning .005 out of true). The bearing was all but completely chewed out of the main and there was a black residue on either side of the cap and block journal for #2. The journal was toast as was the mating surfaces for the cap and block journal (weird but they actually shrank inward and distorted) which was interesting. This was a fully balanced rotating assembly too. In my case, the bearing had spun (badly) then the crank had nothing to support it which cause the banging sound in the motor.
The next setup has lasted over 2+ years of spirited driving and power product testing. As a few of you know, I'm not that easy on them either (lots of stupid stuff). However, on this motor I went with main bearings from Guy that had .001 extra clearance because I could see where the crank had been scraping the old bearings from before. This was in the previous motors I had put together and from old motor examinations. So far so good and knock on wood.
A word on cryo for the crank. This procedure may allow the crank to warp some and then a regrind maybe in order (my observations and experiences when working with this procedure only). If even that will save it. If the need for stress relieving is in need (personal choice), I would recommend Metalaxing it. In this procedure it wont move even .0002. Some one in most big cities has this capability of doing this if it is researched.
Just my 2 cents.
The next setup has lasted over 2+ years of spirited driving and power product testing. As a few of you know, I'm not that easy on them either (lots of stupid stuff). However, on this motor I went with main bearings from Guy that had .001 extra clearance because I could see where the crank had been scraping the old bearings from before. This was in the previous motors I had put together and from old motor examinations. So far so good and knock on wood.
A word on cryo for the crank. This procedure may allow the crank to warp some and then a regrind maybe in order (my observations and experiences when working with this procedure only). If even that will save it. If the need for stress relieving is in need (personal choice), I would recommend Metalaxing it. In this procedure it wont move even .0002. Some one in most big cities has this capability of doing this if it is researched.
Just my 2 cents.
Welcome back mike, its been a while since i've seen you post. How's it going?
super diesel
<<<< Under Pressure
I love this stuff to much to be away. I'm doing very well sir. I hope I find you and every one doing well also.
Henry. You know me.