GM's 2.8L Duramax - Interview with Chief Engineer

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All I ask of GM is please, please, please be reasonable and don't make us get the highest trim level in order to get the diesel. I still don't get what it is about diesels that requires one order the leather seat package...
 
But you wouldn't want to be able to roll coal and hear the diesel go "knock knock" in your MINI brodozer elite pickup?

I can't take anything that is supposed to be "long life" serious that has a rubber belt driven camshaft.
 
Originally Posted By: Miller88
I can't take anything that is supposed to be "long life" serious that has a rubber belt driven camshaft.


Change the belt on time, and even an interference motor has the ability to go high miles. But on a diesel... it'd be nice to skip the belt, because AFAIK, they cannot be made non-interference.
 
I don't really mind belts on non-interference engine. But running the high compression in a diesel, they have to be interference.

But if I'm paying such a premium for an engine, I don't want a cost saving measure like a timing belt to show up.

Just tried to configure one and you definitely can't get one on the WT package
frown.gif
 
Originally Posted By: racin4ds
Hmmm isn't VM Motori the same company making the new EcoDiesel in the dodge Ram?


Yep, that's them. So the more EcoDiesels that Ram sells, the better GM likes it because that improves the bottom line for VM Motori? And since Fiat owns Iveco, it makes one wonder how soon they will replace the VM Motori engine with one from Iveco.

How much of VM Motori does GM own?
 
Originally Posted By: Miller88
I can't take anything that is supposed to be "long life" serious that has a rubber belt driven camshaft.


In theory, a belt can help you sustain that engine for longer than one with a timing chain. A timing chain has a finite life. If they do it right, that life should be pretty long, sure. But it'll eventually wear down and fail. We've seen chains on some recent GM motors fail prior to 100k miles, so durability with a chain is certainly not a guarantee. On top of that, a timing chain is usually behind an oil seal and structural timing cover, making it a real chore of a job to replace or service if that has to be done.

On the other hand, a belt is designed to be serviced, so access is built-in to the system. Belts take more space in an engine design, both because they're physically wider than a chain and because you have to design-in that access area to service them. If I'm buying something that I expect a long life from, as I DIYer, I appreciate something that I can sustain over that long life, rather than a chain that I have to hope they engineered right (and if they didn't, I'm in it for BIG money down the road).
 
Originally Posted By: Miller88
I don't really mind belts on non-interference engine. But running the high compression in a diesel, they have to be interference.

But if I'm paying such a premium for an engine, I don't want a cost saving measure like a timing belt to show up.


That's fair enough. I mostly agree, although I also agree with Hokiefyd: design the darn thing to be serviced! I was never enamored with how an engine mount had to be removed on my TDi to do the belt. 5-6 hour job in experienced hands. Sure, it was only every 100k or so. But you're right, it was a "premium" engine--with premium service costs!

Quote:
Just tried to configure one and you definitely can't get one on the WT package
frown.gif



Go figure. Just as well, I have to think the fuel cost savings won't be realized any time soon.
 
Originally Posted By: Hokiefyd
Originally Posted By: Miller88
I can't take anything that is supposed to be "long life" serious that has a rubber belt driven camshaft.


In theory, a belt can help you sustain that engine for longer than one with a timing chain. A timing chain has a finite life. If they do it right, that life should be pretty long, sure. But it'll eventually wear down and fail. We've seen chains on some recent GM motors fail prior to 100k miles, so durability with a chain is certainly not a guarantee. On top of that, a timing chain is usually behind an oil seal and structural timing cover, making it a real chore of a job to replace or service if that has to be done.

On the other hand, a belt is designed to be serviced, so access is built-in to the system. Belts take more space in an engine design, both because they're physically wider than a chain and because you have to design-in that access area to service them. If I'm buying something that I expect a long life from, as I DIYer, I appreciate something that I can sustain over that long life, rather than a chain that I have to hope they engineered right (and if they didn't, I'm in it for BIG money down the road).


Belts? Chains? Humbug!
Diesels should only have gear-driven cams.
 
Originally Posted By: opus1
All I ask of GM is please, please, please be reasonable and don't make us get the highest trim level in order to get the diesel. I still don't get what it is about diesels that requires one order the leather seat package...


Just looked, you can check the diesel box in the LT (mid-line) level of the 2016 Colorado. (Crew cab, long box) Cloth seats are standard for the LT.

In the base model WT, the only option is the 3.6 liter gas.
 
If GM is serious about getting the new diesel in the hands of the working man they should offer it in the cheapest baseline model, the kind of model that is a real working truck and not just someone's daily driver.
 
Originally Posted By: racin4ds
Hmmm isn't VM Motori the same company making the new EcoDiesel in the dodge Ram?


Yes, but not so surprising when you know that VM Motori started out as a Joint Venture between the Italian partner and General Motors, and whose original mission was to create a Diesel for GM. Chaos in the Automotive market forced GM to divest it's interest, and to put a hold on developing the Truck Diesel.

In a way, the Fiat-Chrysler Motors (FCM) Truck Diesel was a GM motor.
 
VM Motori made the diesel that was in the XJ Cherokee (after the Renault diesel in the early ones) and the diesel in the Liberty / Grand Cherokees.


Originally Posted By: supton
Originally Posted By: Miller88
I don't really mind belts on non-interference engine. But running the high compression in a diesel, they have to be interference.

But if I'm paying such a premium for an engine, I don't want a cost saving measure like a timing belt to show up.


That's fair enough. I mostly agree, although I also agree with Hokiefyd: design the darn thing to be serviced! I was never enamored with how an engine mount had to be removed on my TDi to do the belt. 5-6 hour job in experienced hands. Sure, it was only every 100k or so. But you're right, it was a "premium" engine--with premium service costs!

Quote:
Just tried to configure one and you definitely can't get one on the WT package
frown.gif



Go figure. Just as well, I have to think the fuel cost savings won't be realized any time soon.


I was helping a friend work on a Neon. What a major pain that is! THREE ENGINE MOUNTS have to come off. Not serviceable at all on a Neon.

I do agree that GM has issues with timing chains on overhead came engines. I would be afraid of getting on with the 3.6L for that reason. Although, I think they have the timing chain thing figured out on the 3.6L after a few years.


Originally Posted By: A_Harman
Originally Posted By: Hokiefyd
Originally Posted By: Miller88
I can't take anything that is supposed to be "long life" serious that has a rubber belt driven camshaft.


In theory, a belt can help you sustain that engine for longer than one with a timing chain. A timing chain has a finite life. If they do it right, that life should be pretty long, sure. But it'll eventually wear down and fail. We've seen chains on some recent GM motors fail prior to 100k miles, so durability with a chain is certainly not a guarantee. On top of that, a timing chain is usually behind an oil seal and structural timing cover, making it a real chore of a job to replace or service if that has to be done.

On the other hand, a belt is designed to be serviced, so access is built-in to the system. Belts take more space in an engine design, both because they're physically wider than a chain and because you have to design-in that access area to service them. If I'm buying something that I expect a long life from, as I DIYer, I appreciate something that I can sustain over that long life, rather than a chain that I have to hope they engineered right (and if they didn't, I'm in it for BIG money down the road).


Belts? Chains? Humbug!
Diesels should only have gear-driven cams.


Yes! The OTR trucks use gears - even on the OHC models! And they run >1,000,000 miles without timing chain/belt issues!
 
Originally Posted By: OneEyeJack
If GM is serious about getting the new diesel in the hands of the working man they should offer it in the cheapest baseline model, the kind of model that is a real working truck and not just someone's daily driver.


Give it two years and they probably will, once the newness wears off and the diesel sales start to fall off.
 
Originally Posted By: opus1
All I ask of GM is please, please, please be reasonable and don't make us get the highest trim level in order to get the diesel. I still don't get what it is about diesels that requires one order the leather seat package...


You know, diesels cost more as engines, so the marketing "geniuses" think it only belongs on upscale optioned-out trucks. I felt the same pain when I looked at Colorado/Canyon prices. (((((I've always bought low-cost work truck level trim and saved tons of money, one in '84, '97, '03, '05, now its much harder to do.))))

I do agree they could just offer the base work truck with diesel as a $1,500 option, but their factory production couldn't keep up right now I'm guessing. So, they only offer diesel as a lure on high-profit optioned trucks. Business economics.

Originally Posted By: mrsilv04
Originally Posted By: OneEyeJack
If GM is serious about getting the new diesel in the hands of the working man they should offer it in the cheapest baseline model, the kind of model that is a real working truck and not just someone's daily driver.


Give it two years and they probably will, once the newness wears off and the diesel sales start to fall off.


Factory ramping up for the additional demand this creates means higher profits are to be found in the tricked-out expensive trucks Americans luv to buy. I do believe it would be about $1,500 extra to order """just the diesel engine""" as a one-option, no leather and Sony Playstation in the dash.....
 
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Originally Posted By: A_Harman
Belts? Chains? Humbug!
Diesels should only have gear-driven cams.


As long as they're not nylon, I think gears would be a fantastic cam drive system. Trouble with non-nylon is noise (especially for a consumer-grade engine like this).

No free lunch...just a bunch of trade-offs!
 
Originally Posted By: opus1
All I ask of GM is please, please, please be reasonable and don't make us get the highest trim level in order to get the diesel. I still don't get what it is about diesels that requires one order the leather seat package...


Marketing 101, upselling. Lots of folks want a diesel for various reasons, not all of them logical. As long as a buyer thinks they needs and must have the more expensive diesel option, might as well sell him leather and all of the other upgrades. These sort of buyers generally want the upgrade anyway. This way the manufacturer makes sure it is sold lest some idiot salesman lets this buyer get out the door with a lower level of trim.
 
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