Broken Crankshaft Count?

Please pick the one that you had break


  • Total voters
    185

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
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Curse you for having such impure thoughts....
But I heard Banks say he's got a big pin ready for one. :giggle:
I have a customer wanting to do big things with one. I'm trying to decide if it's worth spending $5k+ on a billet narrow journal crank or not.
 

ikeG

Oughta Know Better
Apr 19, 2011
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Local shop near me had their shop truck break one, apparently.
bc498def50e450bd5e12967d64c502df.jpg


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OleBlackyLBZ

Active member
May 22, 2020
353
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A friend of mine broke his crank a few days ago, it's a stock motor lbz around 700hp. He isn't a member on here if someone wants to add him to the list they can.
 

Leadfoot

Needs Bigger Tires!
Dec 27, 2006
904
31
28
48
Western MA
www.matpa.org
Local shop near me had their shop truck break one, apparently.
bc498def50e450bd5e12967d64c502df.jpg


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It would be interesting to know if it was a broke crank as we think about it (snapped), or if it was something like a spun main or rod bearing from lack of oil or "other" failure...

If it snapped like previous generations...damn!

Edit: I went to their FB page and asked if they knew the answer, it will be interesting to see if they respond.
 
Last edited:

JoshH

Daggum farm truck
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Vendor/Sponsor
Feb 14, 2007
13,716
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Texas!!!
It would be interesting to know if it was a broke crank as we think about it (snapped), or if it was something like a spun main or rod bearing from lack of oil or "other" failure...

If it snapped like previous generations...damn!

Edit: I went to their FB page and asked if they knew the answer, it will be interesting to see if they respond.
I've seen and heard of some bearing failures before. I would be curious to hear the nature of the failure as well.
 

ikeG

Oughta Know Better
Apr 19, 2011
2,466
150
63
Western PA
www.facebook.com
It would be interesting to know if it was a broke crank as we think about it (snapped), or if it was something like a spun main or rod bearing from lack of oil or "other" failure...

If it snapped like previous generations...damn!

Edit: I went to their FB page and asked if they knew the answer, it will be interesting to see if they respond.
They have replied, it was spun bearings.

Sent from my SM-G960U1 using Tapatalk
 

Leadfoot

Needs Bigger Tires!
Dec 27, 2006
904
31
28
48
Western MA
www.matpa.org
I've seen and heard of some bearing failures before. I would be curious to hear the nature of the failure as well.
Just in the L5P or across multiple generations? Just wondering if they beefed up the crank but changed something else (like oil delivery) for the worse, and if so can it be corrected.

I've been thinking about being a guinea pig for an L5P shortblock/longblock swap in my 06, so trying to get as much information on any potential L5P bottom end weaknesses to see if it's worth the effort and accompanying headaches/roadblocks for being one of the first to try publicly.

Obviously if I can make a longblock work with minimal headache that's the route to go, but an L5P bottom end with an LBZ upper end should be doable with some aftermarket help (such as longer pushrods, y bridge spacers (or custom y bridge), reluctor extension harness, CP3 to fuel rail plumbing, etc).
 

Nate’s Dmax

Active member
Dec 11, 2020
203
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Just in the L5P or across multiple generations? Just wondering if they beefed up the crank but changed something else (like oil delivery) for the worse, and if so can it be corrected.

I've been thinking about being a guinea pig for an L5P shortblock/longblock swap in my 06, so trying to get as much information on any potential L5P bottom end weaknesses to see if it's worth the effort and accompanying headaches/roadblocks for being one of the first to try publicly.

Obviously if I can make a longblock work with minimal headache that's the route to go, but an L5P bottom end with an LBZ upper end should be doable with some aftermarket help (such as longer pushrods, y bridge spacers (or custom y bridge), reluctor extension harness, CP3 to fuel rail plumbing, etc).
Your idea sounds interesting. What I’m wondering tho is will the LBZ heads fit on the L5P block? They changed them quit a bit for L5P.
 

gmduramax

Shits broke
Jun 12, 2008
4,078
251
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Nor cal
Just in the L5P or across multiple generations? Just wondering if they beefed up the crank but changed something else (like oil delivery) for the worse, and if so can it be corrected.

I've been thinking about being a guinea pig for an L5P shortblock/longblock swap in my 06, so trying to get as much information on any potential L5P bottom end weaknesses to see if it's worth the effort and accompanying headaches/roadblocks for being one of the first to try publicly.

Obviously if I can make a longblock work with minimal headache that's the route to go, but an L5P bottom end with an LBZ upper end should be doable with some aftermarket help (such as longer pushrods, y bridge spacers (or custom y bridge), reluctor extension harness, CP3 to fuel rail plumbing, etc).

That might work. I tried to get L5P heads on an LLY short block but you would need longer studs and all kinds of custom. But if you were to put all LBZ top end I don’t think it would be much trouble.

I think doing an entire L5P swap would be better that way you benefit from better flowing heads. Run the L5P injectors with the LBZ ecm just run an external reluctor wheel for the crank sensor if the tooth count on the L5P wheel is different
 
Last edited:

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
^^this. Crank sensor count is different for sure so a reluctor on the front would be needed

About the only internal I’d change is pistons, beyond that, I can’t see why that engine wouldn’t hold 800-1000 on good tuning.

I will hopefully get to play with something like this sooner than later. Once my shop is up (waiting on county permit currently), my buddy has an old apache we are going to body drop on a Dmax chassis. If he can find me a gmt800 chassis and we get a decent l5p motor to put in, we will be talking options on power and what to do internal and external of the engine.

Definitely want lbz ecm in there. If all goes through, I’ll document it on here. Could get very interesting
 
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Leadfoot

Needs Bigger Tires!
Dec 27, 2006
904
31
28
48
Western MA
www.matpa.org
Your idea sounds interesting. What I’m wondering tho is will the LBZ heads fit on the L5P block? They changed them quit a bit for L5P.


From my understanding they added bolt holes (but kept the previous ones in the same location). I'm not sure about thickness. I know the deck is higher on the block, necessitating longer pushrods and Y bridge spacers (or aftermarket Y bridge), but if the head is thicker (or bolt bosses higher), then longer studs would be needed as well. My only concern would be piston to valve clearance. I was not thinking that was an issue, but a previous comment about changing pistons has me wondering...

Changing pistons would probably be the "breaking point" of deciding to do an L5P bottom and LBZ top. I would either just build an LBZ or drop an entire L5P at that point.

As for external reluctor, does any one make a kit or can that be changed with EFI Live? Since EFI Live works with multiple generations (which different reluctor counts), I would ASSume it could be changed....(but I've been wrong before).
 

Bdsankey

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Feb 1, 2018
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From my understanding they added bolt holes (but kept the previous ones in the same location). I'm not sure about thickness. I know the deck is higher on the block, necessitating longer pushrods and Y bridge spacers (or aftermarket Y bridge), but if the head is thicker (or bolt bosses higher), then longer studs would be needed as well. My only concern would be piston to valve clearance. I was not thinking that was an issue, but a previous comment about changing pistons has me wondering...

Changing pistons would probably be the "breaking point" of deciding to do an L5P bottom and LBZ top. I would either just build an LBZ or drop an entire L5P at that point.

As for external reluctor, does any one make a kit or can that be changed with EFI Live? Since EFI Live works with multiple generations (which different reluctor counts), I would ASSume it could be changed....(but I've been wrong before).

An external reluctor is how Banks runs their "big pin" cranks in L5P blocks, they have it as part of the damper kind of like a Cummins.

If it were me I would be dropping in a complete L5P and making the wiring work as the head flow gains are HUGE compared to anything 01-16. The only sensor that would take some (not much) work would be the reluctor. I would, myself, go to an external with the same tooth count as the LBZ/LMM reluctor to limit anything crazy inside the ECM that had to be done simply because I don't have the tuning/patching "know how" to do it. I do know Ken has gotten it to work on either an LBZ or LMM ECM unless I was hallucinating.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,694
5,851
113
Phoenix Az
^^this. Crank sensor count is different for sure so a reluctor on the front would be needed

About the only internal I’d change is pistons, beyond that, I can’t see why that engine wouldn’t hold 800-1000 on good tuning.

I will hopefully get to play with something like this sooner than later. Once my shop is up (waiting on county permit currently), my buddy has an old apache we are going to body drop on a Dmax chassis. If he can find me a gmt800 chassis and we get a decent l5p motor to put in, we will be talking options on power and what to do internal and external of the engine.

Definitely want lbz ecm in there. If all goes through, I’ll document it on here. Could get very interesting

To clarify, I’m talking about a L5P long block using lbz electronics. I want those heads!!!
 

Yngdmax92

Active member
Sep 26, 2013
962
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There has already been someone who put a long block l5p in a lbz platform and ran it off the factory ecm. I am almost certain he just spliced in the l5p pig tails onto his lbz harness, and some other small things and ran it. Didnt he put a post on here as well?