Cracked LML pistons

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,517
501
113
Central OH
Not sure how much it has to do with it but none of the piston squirters were centered in the piston holes, a few were what id call only getting half the spray into the hole at BDC.

That sir, is a problem. Are the cooling nozzles twisted, or is it the piston dimensions that are off?
 

jkholder09

New member
Jan 8, 2012
1,188
0
0
Maryland
The only cracked lml pistons I have heard of were on trucks with H & S tuners.
I have never heard of an lml piston crack efilive.

I have abused some lml pistons badly. They were delipped.
Get the owner some tunes from Kory this time.
 

DIESELMAFIAPER.LB7

<----new hotness
Jan 17, 2010
5,163
12
38
idaho
shop.dieselmafiaperformance.com
I have tuned quite a few 650+ hp LMLs and around 1500+ LMLs i have tuned overall... I have not heard of anyone cracking pistons on them yet. My personal LML is running around 750+hp with 2600uS and 28* (its on borrowed time i know) and is still playing nice. Obviously, it is all a time bomb when we increase power.

H&S tunes are around 1400uS on hot with 18.9* of timing.... I would be willing to say either the following:

A.) Defective from factory

B.) Major abuse while running hot tuning

I am excited to see more and more LMLs modded and everyone TRULY push the limits. All i can speak from is my personal experience with them and my thoughts. Hope this adds a little!

Kory

Exactly I am in the same boat I've loaded your tunes and mine no cracked pistons... people need a brain when using these trucks and not tow on max effort tuning
 

bluessmax

Tabasco Injected!
Nov 4, 2010
1,143
6
38
Lake Charles, la
My truck never comes off kill mode, but when I tow I don't use more than like 450hp. It's so crazy how your foot can control fueling... Just nuts huh? Lol
 

FC5452

Member
Mar 17, 2013
301
0
16
Eastern PA
I saw that post On FB last night, phone does not do it justice, but looking at that scar pattern, the majority of the burn took place right at the crack, were all 5 holes similar?
Though it seems you hear more and more about a cracked piston or two on the LML are they year specific? i only ask, because I have to agree with Kory on this one, I had just the H&S tune prior to MCC and it never left HOT. towed with it so the right foot will play a lot into it, but what confuses me is the heat was only concentrated to the one side, which leads me to believe either to early with injection or misaligned injectors?
Off base here? I open to criticism can only learn better by asking :D
 

ikeG

Oughta Know Better
Apr 19, 2011
2,472
152
63
Western PA
www.facebook.com
Stock trans, just h&s and dpf delete. This truck towed for a living, but we're talking 30k+ gcw, not just a skid steer or something. In fact, the co. That had this truck hauled a case 580k backhoe out for us with there new pickup that replaced this lml. Driver said he used to drive a dmax but it always used antifreeze and they could never figure it out, so they traded it.
 

DIESELMAFIAPER.LB7

<----new hotness
Jan 17, 2010
5,163
12
38
idaho
shop.dieselmafiaperformance.com
Stock trans, just h&s and dpf delete. This truck towed for a living, but we're talking 30k+ gcw, not just a skid steer or something. In fact, the co. That had this truck hauled a case 580k backhoe out for us with there new pickup that replaced this lml. Driver said he used to drive a dmax but it always used antifreeze and they could never figure it out, so they traded it.

:roflmao: nice
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,517
501
113
Central OH
yes, pins get them close but are never perfect on any engine. yes all are burnt on the underside.

High oil temps most likely. Anything over 250F post oil cooler usually doesn't do much good for the pistons. Cut one open and see if they're clogged internally.

I work on mainly Cummins med/hd and the cooling nozzles are never off as far as you make it seem this engine was. :confused:
 

05_LLY

Out-A-Time
Aug 7, 2006
1,756
1
36
43
Norvelt, PA
High oil temps most likely. Anything over 250F post oil cooler usually doesn't do much good for the pistons. Cut one open and see if they're clogged internally.

I work on mainly Cummins med/hd and the cooling nozzles are never off as far as you make it seem this engine was. :confused:

im prob makin it up then, have you ever been in a dmax? the nozzle is easily movable 1/4" maybe more, i never measured, i just make sure they are aligned when i put engines together.
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,517
501
113
Central OH
im prob makin it up then, have you ever been in a dmax? the nozzle is easily movable 1/4" maybe more, i never measured, i just make sure they are aligned when i put engines together.

I'm not saying you're wrong. Never cracked open the bottom end on a Dmax, sorry. Locating tabs/pins on Cummins engines fit tighter than that!
 

juddski88

Freedom Diesel
Jul 1, 2008
4,657
120
63
Chesterfield, Mass.
im prob makin it up then, have you ever been in a dmax? the nozzle is easily movable 1/4" maybe more, i never measured, i just make sure they are aligned when i put engines together.

I agree with you Caleb, but I have a question: have you seen significant damage caused by prolonged run time of a cast piston which was starved of oil supply due to a broken squirter?
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,677
1,947
113
Mid Michigan
im prob makin it up then, have you ever been in a dmax? the nozzle is easily movable 1/4" maybe more, i never measured, i just make sure they are aligned when i put engines together.

You arent kidding. Really have to watch that as you install the pistons/rods.
 

05_LLY

Out-A-Time
Aug 7, 2006
1,756
1
36
43
Norvelt, PA
I agree with you Caleb, but I have a question: have you seen significant damage caused by prolonged run time of a cast piston which was starved of oil supply due to a broken squirter?
i have never seen one with a broken squirter other than an engine with major failure so i cant say for sure on that. i can say the wrist pins and bushings were all ok in this engine so even though they were not aligned as good as id wanna see them, im not sure there was a shortage of oil in the area. just me thinkin out loud there though.