I used to not worry about my crank breaking even after reading threads like this but I know 2 guys personally who had cranks break on tune only trucks in the last 6 months , one LLY one Lb7.....
Broken Crankshaft Count?
- Thread starter EDP
- Start date
I heard it talking with Joe at HSP. I figured he is credible enough
After digging into this more, the customer was NOT running an alt fire cam. It was a miscommunication of what he thought he was running. :thumb:
When it comes to balancing the crank what would be the right way? Say your going to run it 4000 rpm's at most or does that even matter? Like what would you tell the machine shop how you want it done i know you need to give them all the pistons/rods/pins/rings/ flex plate and balancer so it can all be balanced as a set right?
Mark from Danville "We have a built lly customer that has broken two cranks back to back that were internally balance with a stock firing order and both broke in the less than 3,000miles range and he was not beating on the truck at all cause he was scared of the truck.On the third time of rebuilding it we did an external no frills balance and changed the cam to an AF cam of the same profile grind and he has already doubled the mileage without issue "
You will want an External balance done.
Couldn't agree more, it's just in the lime light here with the built trucks so it has more attention given. It is a very small percentage that is actually failing in the real world but when it's yours it feels like it everyone of them failing. I'm just worried about the best possible parts combinations for my customers without worrying about failures like this.
I was thinking about how much of an effect clearances have on them breaking. Would a tighter tolerance motor be more prone to crank breakage than a "looser" motor, or am I way off base?
Better hope it doesn't bust damian there's a dmax coming to your town in a year and a half
Sent from a truck somewhere in the US
If only it were that simple
I had this discussion with Dustin (chevyburnout1) last night. It's helpful to know the stats and situations under which cranks broke. Equally interesting to me is just how many builds over 650HP HAVE NOT had issues with cranks. It would put things into perspective to get data like this. We could gauge what percentage of built/stock had crank issues and what percent of built motors will loose a crank. The data needs to be all inclusive IMO and perhaps we could start a thread where just non broken cranks on built motor trucks or higher HP stock motor trucks can report in. Just a thought
I agree, not sure who does the poll thing at the top of the trend.maybe they could add a couple more selections.
I don't believe the breaking is related to HP. I'm sure it increases the risk, but when you have stock or mostly stock trucks breaking cranks, it makes it difficult to point the finger at HP or Tq.
I agree, I see far more completely stock trucks come into the shop with broken cranks(lbz/lmm mainly) than higher powered trucks. 99.5% of the built motor guys or higher hp guys all broke just cruising down the road not while making a lot of hp.
Was this why your engine was out again Brian? And NJ?!?! When did you leave Cali?
Depends on which time, it was out a while ago for the broke crank and recently when I cracked the cylinder wall.
Ya, NJ. I could live in van down by the river in CA or a house in NJ, so I live in NJ since July.