LLY piston hit valves spun bearings recommendations?

Scrap Dog

New member
May 31, 2015
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Warsaw, IN
Hey guys, finally saved some money and found out what happened to my motor. Number 4 piston spun a bearing and the piston hit the valves. So I am going to get a valve job done for sure. Then at minimum replace that piston, should I replace all 8 Pistons. The moto has 190k. I am doing all 8 piston rings as well. I am not sure about the crank yet or condition of the rods. I know Duramax in different years did stronger rods crank etc. I am just seeing what you guys think I should do on it. Since I'm doing all this work I am keeping the truck for a long time. I just tow a camper and do have efi live and other bolt ons, stock transmission. I just want it to last and not have to do this again. Thanks for any suggestions! I am also head studding, and doing a lift pump, and adding a cts monitor instead of gauges. It's only money right?
 

Scrap Dog

New member
May 31, 2015
25
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0
Warsaw, IN
I'm not talking sled pulling or drag racing parts. With new parts and to do the whole motor I'm looking at 7500 that's including honing, valve job, 8 Pistons, piston rings, rods and new crank, head studs. If I do bare minimum it is like 6200. My question I guess is should I not gimp out on this, and just replace all ford 7500
 

Scrap Dog

New member
May 31, 2015
25
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0
Warsaw, IN
Looking for more reliability. I have stock trans, really not looking to rebuild it or strengthen unless it fails. I do have efi live and powermax stage one turbo. Bigger inter cooler up and down pipes. K and n cold air intake and afe mouthpiece. Efi is only a max of 110 hp. Mostl run a 80 tune. So that's what I got going on. Not looking to go crazy cause of trans just reliability.
 

Burn Down

Hotrodder
Sep 14, 2008
7,092
28
48
Boise Idaho
At those power levels LB7/LLY pistons and LBZ/LMM rods will be fine. I would put head studs in at that time just for piece of mind, if you ever need to remove a head then you can reuse the stud, the stock bolts are one time use.
 

Scrap Dog

New member
May 31, 2015
25
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0
Warsaw, IN
Yes doing the head studs for sure. I was told the crank was not the strongest in the LLY motor and another stock Duramax is stronger such as the lbz or lmm. Not sure which. A machinist told me that. Yes I am purchasing all new LLY pistons. I am pretty much going to have a new motor it seems but with better stock parts of ya know what j mean.
 

Scrap Dog

New member
May 31, 2015
25
0
0
Warsaw, IN
Ok will see then. Everything is going to machine shop Monday. Hopefully get her back in a month. It has been a long summer without her. Thanks for all the suggestions. I just want to make sure the motor will last. The 190k just seems premature for big failure to me.
 

ripmf666

Active member
Sep 20, 2006
15,123
14
38
47
Wentzville Mo
I'm not talking sled pulling or drag racing parts. With new parts and to do the whole motor I'm looking at 7500 that's including honing, valve job, 8 Pistons, piston rings, rods and new crank, head studs. If I do bare minimum it is like 6200. My question I guess is should I not gimp out on this, and just replace all ford 7500


If your spending that on stock parts I would upgrade some. The Lbz rods is said to hold 10 to 15% more then lb7/Lly rods that's not a lot. Your already having to balance the setup being your using lb7/Lly pistons with a Lbz crank if you go that way. If crank checks out I would reuse it there all breaking my Lbz crank lost life 80k after the build running on a 580/600 dd tune was at around 800 but not for long. Had a total of 112k on Lbz crank from when truck was new and after build.

The brain crower bundle with Mahle race cast Pistons would work great for you. Comes with bearing set and overhaul gasket kit. 4,275.00 shipped.

http://www.duramaxdiesels.com/forum/showthread.php?t=65092