Note the lack of re-enforcing steel inserts. This piston is not made to take the abuse the stock LB7/LMM is IMO. If/when I get a chance, I'll run it through the FEA and see how it stacks up.
LML Internals
- Thread starter SteveFord
- Start date
Is it just me or does the metal of the lml look grainy?(i think thats the word I want to use) Almost looks like there is "trash" in it?
Is it just me or does the metal of the lml look grainy?(i think thats the word I want to use) Almost looks like there is "trash" in it?
It makes me wonder if it's forged. Note the casting core markers on the the LBZ on the inside skirt that are missing on the LML.
Unlikely though. If it is, that is some wicked technology to get the oiling ring and top ring insert into a forging. They would have to cast first, then not deform the ring or insert during the forge.
But 20 years ago, I would have thought the LB7 piston was impossible to cast.
Is it just me or does the metal of the lml look grainy?(i think thats the word I want to use) Almost looks like there is "trash" in it?
All I see is what looks like metal shavings from cutting the piston in half.
The dars spots dont look like shavings to me:dontknow:All I see is what looks like metal shavings from cutting the piston in half.
looks more like imperfections
hard to tell though without having the piston in hand
The LML is definitely a cast piston. The casting technique is very similar to that of the LBZ/LMM. I don't expect these to be any better than the LBZ/LMM piston, with regard to durability.
The thinner rod allows for more mass in the piston, which should prevent cracking, however the overall density of the material will still burn through, as is so common on the LBZ/LMM pistons.
LML rod is on the right. They certainly reduced the load capacity of the wrist pin bushing/small end of the rod by narrowing it down.
The thinner rod allows for more mass in the piston, which should prevent cracking, however the overall density of the material will still burn through, as is so common on the LBZ/LMM pistons.
LML rod is on the right. They certainly reduced the load capacity of the wrist pin bushing/small end of the rod by narrowing it down.
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Tony Burkhard
Allseason Diesel Per.
I ran the LML block, crank, oil pump, oil pan and front cover for one pulling season. The block is 20 lbs heavier than the LBZ/LMM block and the oil pump has 11% more volume.
When the blade gets dull, it "smears" against the blade and makes it look that way. Notice on the right side, it's "clean", then left = "dirty".
To avoid that, simple way when using a bandsaw/hacksaw/mill/drill is keep a can of WD-40 handy and spray every 10 seconds or so. Clean way is to use water-based coolant in a spray bottle. Dish soap and water works in a bind.
Not a die maker, but many of my customers are:
Note that the LBZ/LLY is a 3 or 4-piece inside core. Normally the center pulls down, the R/L halves push in, to eject the part. Die casting.
This is often necessary because as the aluminum cools, it locks onto the die and can't be ejected.
The LML appears to be a 1 piece core. Forgings are usually 1 piece, or castings that don't have internal (female) surfaces that will stop ejection.
It seems as if the block and oiling system may be better in the LML, but the rods and pistons are no better (and possibly worse).
Seeing as how rods are replaced in a performance build anyways, that doesn't really matter, just leaving the pistons as a possible additional cost (most use different pistons in their builds anyways).
This one died off a while ago I was wondering if anyone had the balls or wipes their ass with $100 and likes to gamble gave these a shot in 600hp or bigger motor
This one died off a while ago I was wondering if anyone had the balls or wipes their ass with $100 and likes to gamble gave these a shot in 600hp or bigger motor
http://www.duramaxdiesels.com/forum/showthread.php?t=32833