Stock LBZ Rebuild

[Power Shift]

I have a 2007 Duramax LBZ with about 360,000 on the truck when the motor decided that it wanted to spin rod bearing on the crank, which resulted in the piston to touch some of the valves.

The valves nor the pushrods look bent. However, the piston does show where the valves hit. The crank also does have some wear on it where the connecting rod attaches.

I am looking to get the truck up and going as soon as I can, but I am not sure on what my rebuild options are. I would replace the push rods & the valves b/c if they touched I am going to assume they are bad (don’t want problems down the road). This truck is staying completely stock as it is a DD :baby: (no need/want for performance build).

I have heard from some people that I have called around that the crank can be turned, and others say it is a bad idea.
1. Can the crank be turned and still be reliable?

2. Is there a 'stock' rebuild kit, out there for a reasonable price?

3. Or would it be better/cheaper to bag it all and throw in a used motor w/about 169k miles on it?

 

[Huffy67]

Take it apart, take the block, crank, rods, and heads to a machine shop, have them check the block out to make sure it is all good(I'd say it will be, but better to make sure) have the crank turned if need be, they will know if it's in or out of spec. Check the rods or atleast that one rod for straightness, have the heads checked and worked on as necessary, find a used piston, then all you need is some bearings, rings, and a complete gasket kit. Hopefully she'll go another 360k!!!


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[Power Shift]

Take it apart, take the block, crank, rods, and heads to a machine shop, have them check the block out to make sure it is all good(I'd say it will be, but better to make sure) have the crank turned if need be, they will know if it's in or out of spec. Check the rods or atleast that one rod for straightness, have the heads checked and worked on as necessary, find a used piston, then all you need is some bearings, rings, and a complete gasket kit. Hopefully she'll go another 360k!!!

Perfect! I called a machine shop this morning who works on diesel motors and he said that they would be able to turn the crank. I think this will be the best route to go and the most cost effective.

I don't want to run LBZ pistons b/c of the cracking issue, BUT I'm not concerned enough about them to swap them all out for LB7 pistons.

Thanks for the direction!

 

[ty_LBZ]

Toss a alternate firing cam in there too!

 

[Huffy67]

Awesome!! Post up some pics throughout the process


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[malibu795]

I spent ~1000.00 in consumable parts, ie bearings non reusable gaskets(a lot are resusable) on my short block rebuild while back.
Stock head bolts
Fly wheel bolts
Head gaskets
Injector cooper washers and o rings
F/R main seals
Main and rod bearings.
Did a bore n balance on my old lbz block.. Told the machinist check everything if its in spec don't touch it. Had ~4300.00 in parts and machine cost including new .020 over pistons.. Be a little more since you might have valve train damage.. Could upgrade to SoCal valve springs while your there

 

[Power Shift]

Finally I have been able to get some pictures. After tearing the motor completely down, I don't think they will be able to turn the crank on this puppy .

When we first tore it down, we took out the bad rod/piston (piston #2) to see what the damage was and it didn't look too bad. But when we pulled #1 we could see the extent of the damage to the crank. The block is still good though (no visible damage).

#8 piston was starting to crack at the lip too-

 

[Huffy67]

I just swapped out a piston in my lb7 that was cracked just like that! One of the skirts was plum gone on mine too though!


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