Diesel Power (Wishlist#5): ISB Aluminum Head

Dmax's seem to be holding up quite well with an iron block/aluminum head.
 
When I was young, my parents had a 2.5L Plymouth Acclaim. Iron block and aluminum head. It would lose a headgasket every 60k miles like clockwork. The 3rd time we lost the head gasket, we had to get a used head cause the first one had been machined flat too many times. On the last head, we overtorqued the headbolts and it made it 80K before it started to leak.

When we talked to the machine shop, they said it was common for that motor to loose headgaskets. Something about iron and aluminum having different expansion rates causing the head gasket to wear prematurely.

I also think the torque to yield head bolts were problematic. I think 60 ft lbs plus 90 degrees didn't really yield consistent clamp load on the head.
 
Big Blue24 said:
When I was young, my parents had a 2.5L Plymouth Acclaim. Iron block and aluminum head. It would lose a headgasket every 60k miles like clockwork. The 3rd time we lost the head gasket, we had to get a used head cause the first one had been machined flat too many times. On the last head, we overtorqued the headbolts and it made it 80K before it started to leak.

When we talked to the machine shop, they said it was common for that motor to loose headgaskets. Something about iron and aluminum having different expansion rates causing the head gasket to wear prematurely.

I also think the torque to yield head bolts were problematic. I think 60 ft lbs plus 90 degrees didn't really yield consistent clamp load on the head.
Click to expand...


Maybe for that motor but just because you have an iron block/aluminum head combo doesn't mean you're going to go through head gaskets like it's your job. I shouldn't have to mention countless high HP engines that run the same type of combo.

It would be cool for a weight savings off the front of the truck but aluminum heads also make less power than a comparable iron head. So there's a trade off, the repairability of aluminum would be a nice bonus though. Just my $.02
 
Turbo Performance said:
It would be cool for a weight savings off the front of the truck but aluminum heads also make less power than a comparable iron head. So there's a trade off, the repairability of aluminum would be a nice bonus though. Just my $.02
Click to expand...

:umno:

head material isnt going to make a that big of an effect on performance. there is a slight amount of heat loss from the combustion chamber compared to iron, i would be surprised if it made a 1-2% difference.

Factor in the fact that you're not buying a "stock" aluminum head. head will have bigger ports, possibly bigger valves already in it. You would defiantly be seeing improvements.
 
Rollin Coal said:
Factor in the fact that you're not buying a "stock" aluminum head. head will have bigger ports, possibly bigger valves already in it. You would defiantly be seeing improvements.
Click to expand...


True. My image of an aluminum head is far different than the out of the box Cummins. Lots of meat, tall risers, very little coolant.
 
I see an aluminum 12v head before one for an ISB...

But I hear a lot more talk than I actually see metal parts.

Hamilton is working one one as well...
 
displacedtexan said:
I see an aluminum 12v head before one for an ISB...

But I hear a lot more talk than I actually see metal parts.

Hamilton is working one one as well...
Click to expand...

Just for information : Cummins have made few aluminium 12V head ,also blocks ......

We have pictures even in CompD:woohoo:
 
Big Blue24 said:
When I was young, my parents had a 2.5L Plymouth Acclaim. Iron block and aluminum head. It would lose a headgasket every 60k miles like clockwork. The 3rd time we lost the head gasket, we had to get a used head cause the first one had been machined flat too many times. On the last head, we overtorqued the headbolts and it made it 80K before it started to leak.

When we talked to the machine shop, they said it was common for that motor to loose headgaskets. Something about iron and aluminum having different expansion rates causing the head gasket to wear prematurely.

I also think the torque to yield head bolts were problematic. I think 60 ft lbs plus 90 degrees didn't really yield consistent clamp load on the head.
Click to expand...


Maybe this was before the MLS gasket was available? That's what's making it work today.

TTY head bolts are actually the whole point of consistent clamp load because once they start to yield, the stress (load) stays constant in the material as the strain (displacement) continues. The stress-strain curve is flat there.....so it's an idiot-proofing measure.


I think the old stuff was just poorly designed and is not indicative of what can be done with modern tech. There is a real reason for TTY bolts and that's why they're so common today.
 
I can see it benefiting drag racers, but for sled pulling, you need all the weight out front you can get anyway, no sense trying to save with the head material.
 
Rollin Coal said:
1000's of motors use an iron block with aluminum head(s)
Click to expand...

that is very true 1000's of motors do use aluminum heads but not very many diesels because of the compression ratio and thats why gm with military grade hummers with the dirty maxes put all cast iron heads on them becaus they where having such a high failure rate!! maybe for a all out pulling truck with a filled block they would work okay with plenty of cool down time cycles but if aluminum was so great on diesel how come cat and IH and JD an cummins have not used them there the top 4 so I say they have lots of testing and reasonings behind them thats just my thoughts on the subject
 
I know for a fact that the aluminum head wouldn't stand up unless you were able to add studs between the oem head bolts. I know a lot Jetta TDIs that are hopped up can't keep that aluminum head from lifting between the studs and blowing hd gaskets. Now that's with 40psi tops, imagine 70+.
 
CanadianCarGuy said:
I know for a fact that the aluminum head wouldn't stand up unless you were able to add studs between the oem head bolts. I know a lot Jetta TDIs that are hopped up can't keep that aluminum head from lifting between the studs and blowing hd gaskets. Now that's with 40psi tops, imagine 70+.
Click to expand...

That problem is now fixed; people were using the wrong stud. This problem was a that people were using a Chromemolly material, back cut stud that only torqued to 88 ft lbs. It was designed, for a cosworth gas engine. With the New ARP 2000 material, the problem is now solved. The Duramax has a aluminum head and has no problems that traced back to the material of the head.
Top Fuel engines are aluminum heads, and they make 1000 hp per cylinder.
If you had a cylinder head that flowed 400 cfm of air, the need to make ridiculous boost to get air in the engine would no longer be necessary
 
Yeah that is fine, but even with ARP studs, they are too far apart on the cummins head and inbetween studs will lift with an aluminum head. Just look how far apart the studs are. Now look at a top fuel head, look how close they are together and how many of them are there. It is like all those guys who went out and bought cometic multilayer steel head gaskets for their trucks and were machining just the head and were wondering why the gasket was failing, because it was lifting between the studs and also maybe decking the block along with the head would have helped.
 
You must log in or register to reply here.
Top