Duramax Monotherm Pistons

Yellow Jacket

WannaBe Sled Puller
Feb 11, 2009
917
0
16
Waterloo, IA
If you pull the piston out, and it is split down the middle, you have a bad one.

Thanks, that is what I figured....

I have a customer truck with a 2004 LLY with a hole or a cracked piston on #1, and he is trying to decide the best route with my help....

But my built motor, that I put together, with cut and coated pistons from SoCal ended up cracking a piston after two seasons at 900+ rwhp and 80+ hooks and 6000ish street miles... But I needed the steel ringlands because it was a daily driver in the off season....
 

McRat

Diesel Hotrodder
Aug 2, 2006
11,249
26
38
64
Norco CA
www.mcratracing.com
Thanks, that is what I figured....

I have a customer truck with a 2004 LLY with a hole or a cracked piston on #1, and he is trying to decide the best route with my help....

But my built motor, that I put together, with cut and coated pistons from SoCal ended up cracking a piston after two seasons at 900+ rwhp and 80+ hooks and 6000ish street miles... But I needed the steel ringlands because it was a daily driver in the off season....

:D

Sorry for the easy shot. ;)

Folk are claiming the Arias pistons aren't having ring failures. I don't know personally. Haven't heard of either cracking or ring land failures.

Steel sounds like the solution for the kind of truck he wants.

If the new piston is 20% heavier, I don't think that's where they will end up at in the long run, nor do I think it's a deal breaker. Lighter pistons = more HP and mileage, plus lower emissions. Mahle claims their passenger car steel pistons are lighter than the alum ones.

It's all about strength at 500°F. Alloy steel can be full strength at these temps, and several times stronger than aluminum. The trick is how to make a light piston easily. Mahle is making 2-piece steel units as well to get the weight down.
 

camomax

pushing the limits
Nov 5, 2008
503
0
0
55
Florida
Yep...or a carillo/crower with a modified small-end.

DTS currently has two lb7's and one lly running lml pistons. Two on carillos and one on crowers. I'm not 100% sure how long they have been in, but both are big hp motors, and testing has gone well. David is now in a joint venture with Manley, making aftermarket rods for all Duramax pistons. Testing is underway. David can provide more info.
 

MACKIN

Smell My Finger...
Aug 14, 2006
3,948
1
0
Connecticut
Anybody figure out who got the other four sets yet?

1) TTS?
2) Braydon or is it Brandon? Who did the TV show there awhile back?
3) Who else is got a fast truck out there or a builder?

Who's getting Socal's set?

If we can't figure it out we could always start some rumors. :D
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,701
756
113
Texas!!!
Anybody figure out who got the other four sets yet?

1) TTS?
2) Braydon or is it Brandon? Who did the TV show there awhile back?
3) Who else is got a fast truck out there or a builder?

Who's getting Socal's set?

If we can't figure it out we could always start some rumors. :D
Curtis (Halverson?) from DPR, Tony Burkhard, Eric Merchant, Randy's Machine. Just a few possibilities off the top of my head.
 

TrentNell

Finally underway !!!!!
Jul 7, 2008
7,543
0
0
44
slc tuah
Anybody figure out who got the other four sets yet?

1) TTS?
2) Braydon or is it Brandon? Who did the TV show there awhile back?
3) Who else is got a fast truck out there or a builder?

Who's getting Socal's set?

If we can't figure it out we could always start some rumors. :D

If i had to guess I would think Steve would test his set in Bucks truck , the other sets , I would like to see Rob try a set , he puts out plenty of HP and also gets a lot of passes in per year , I would still try a set pending cost and if a set was even available .
 

MACKIN

Smell My Finger...
Aug 14, 2006
3,948
1
0
Connecticut
Forgot about Banks Tripp you mentioned 3 I thought you said 5 sets were known off? 2 sets for replacements not out in the field?
 

duramax3388

Member
May 22, 2008
447
0
16
44
Zanesville Ohio
First off I think treads like this make this forum the best Thanks Pat and Crew. One thing to add is that these (test) pistons are billet not forge like the productions will be what effect will this have on weight with the finished product?
 

McRat

Diesel Hotrodder
Aug 2, 2006
11,249
26
38
64
Norco CA
www.mcratracing.com
First off I think treads like this make this forum the best Thanks Pat and Crew. One thing to add is that these (test) pistons are billet not forge like the productions will be what effect will this have on weight with the finished product?

Forged is stronger, so they can make the walls thinner. Whether that's what happens? Guess we will see.

I would guess Banks would get 2 sets, as they have both a truck and a dragster that could test them.
 

Trippin

SoCal Diesel
Aug 10, 2006
663
2
0
These were actually cut from the Cummins forging.
The amount of machine work it took to get to the finished product, they might as well be billet.

Not practical to produce them this way in production. I would expect the weights to remain consistent unless there are design chnages based on testing.
 

duramax3388

Member
May 22, 2008
447
0
16
44
Zanesville Ohio
Forged is stronger, so they can make the walls thinner. Whether that's what happens? Guess we will see.

I would guess Banks would get 2 sets, as they have both a truck and a dragster that could test them.
That's kinda what I was thinking as the end product might be lighter or stronger. The question is which.