I am real close to buying an 05 Dmax and just wanted to hear from the ones in the know about aluminum heads on these motors. I am no diesel expert and need help getting up to speed on the fuss over aluminum heads on a diesel motor. I was close to going with the Dodge/Cummins set up but the small cab on the Dodge and my Chevy/GMC loyalty is keeping me here. Help educate me, please!!!! Thanks for the help. Joe

don't think I have heard of any issues about them since I have been a member and owner.

Hey,

Have a look at VW and their history with aluminum heads on diesels. Never an issue with them!! Their longevity record is second to none including Cummins, infact Cummins could learn more than a few things from VW!!

Take care,

Will

don't think I have heard of any issues about them since I have been a member and owner.


Precisely............because there is NO ISSUE. There was a big fuss over this when the dmax first came out. There has yet to be any problems even when the motor is pushed to the extremes at the track.

The only issue with aluminum heads have been the rumours started by others who believe cast iron is superior on a diesel.

This engine is designed for Aluminum heads. This is no bandaid retrofit.

I have personally only seen 1 Duramax with a head failure and IIRC it was a crack/porosity defect at the injector sleeve area

I wouldnt worry about it.

I'll throw in my 0.02 worth. First, my source of info is my Son-in-Law. He was a shift supervisor in an aluminum foundry. The aluminum is not pure, no such thing. There are other alloys added for strength and heat disapation.(sp?)

The foundry he was at in Michigan makes aluminum water pumps and housings, aluminum blocks and 'heads'. All put together, they're call a Viper V10. I would think there are more D/A on the road than Vipers, but either way, haven't really seen a whole lot of either one setting along side the road with a puddle of aluminum under 'em. :lol: :lol:

The GM gassers have had aluminum heads for some time now. Very few comments about heads on the board.

Jim

Ford 6.0's are having coolant issues.

They are iron head.

The Dodges need help when they run big boost.

It appears the Duramax is at least as good at holding head gaskets as either of those 2.

The aluminum heads are actually an asset. They pull heat away at a faster rate and transfer it to the coolant more efficiantly than cast iron.

After spending a year on a couple of Ford forums, my understanding is the PSD 6.0 isn't having cooling problems, but rather head bolt problems. This is occurring on 6.0s that are pumped up (like 100hp + tune programs) where the bolts stretch and then the head gasket and mating area are compromised, which over pressures the cooling system and blows coolant out because of that...

My $.02 worth... Being new to the Dmax side myself, I thought about asking the same question on aluminum heads (remembering all the hand wringing going on without data when Dmax came out). I did some searches and it certainly seems the Dmax configuration is at least as reliable if not more so in this dept...

If there was an abundance of problems with AL heads they would have been done away with a long time back.

Lets look at the Coefficient of Linear Expansion (per degree C) of the two metals, aluminum and iron.

Coefficient of Expansion= (coefficient)(length)(rise in temp)
Aluminum: 0.000024
Iron: 0.000011

This tells us that aluminum expanses twice as far as iron when the temp. change and length is the same. But keep in mind this is LINEAR expansion not expansion of complex shapes(clyinder head/block). But it should be close enough for this argument.

When the aluminum head expandes it will expand in all directions including upwards. So if the aluminum expandes twice as far as the steel head bolts, which will limit the upward expansion of the head, the aluminum will expand downward, closer to the block, which will make a tighter gasket seal.

Also, aluminum transfers heat, or gives up heat, much better than iron. Some will argue that the aluminum is running at a cooler temp than the iron, therefore not expanding as much and may be expanding at an equal amount as the iron.
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2003 Chevy ExtCab, Long Box, 2500HD, 4x4, D/A, High Idle, Overloads, Bone Stock

Make sure you use that orange 5-year coolant. The 2-year green stuff corrodes aluminum components like there is no tomorrow.

Lets look at the Coefficient of Linear Expansion (per degree C) of the two metals, aluminum and iron.

Coefficient of Expansion= (coefficient)(length)(rise in temp)
Aluminum: 0.000024
Iron: 0.000011

This tells us that aluminum expanses twice as far as iron when the temp. change and length is the same. But keep in mind this is LINEAR expansion not expansion of complex shapes(clyinder head/block). But it should be close enough for this argument.

When the aluminum head expandes it will expand in all directions including upwards. So if the aluminum expandes twice as far as the steel head bolts, which will limit the upward expansion of the head, the aluminum will expand downward, closer to the block, which will make a tighter gasket seal.

Also, aluminum transfers heat, or gives up heat, much better than iron. Some will argue that the aluminum is running at a cooler temp than the iron, therefore not expanding as much and may be expanding at an equal amount as the iron.
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2003 Chevy ExtCab, Long Box, 2500HD, 4x4, D/A, High Idle, Overloads, Bone Stock

when they first came out with Al heads on gassers did they not have trouble with warped heads , i believe the general started using reverse flow cooling, and it made a significant differance, in head life and such, does the dmax do this?

The only diesel aluminum head problems I have ever heard of is with the early (1986-87) 603 series Mercedes engines. The early castings were very prone to cracking, although most attribute this to overheating the jury is still out as far as I am concerned. It seems more like a design flaw. At any rate, the later castings corrected the problem and are pretty much bullet proof.

Go to a machine shop, take a look around at warped/cracked heads. 6 billion irons, and I have never seen an aluminum head in the mix for the same problem. I personally have owned a bunch both, and while I have killed off many iron heads I have yet to have a problem with an aluminum one.