GM Engineers Design NEW 4.5L Duramax Turbo Diesel V8

[Streamer1]

Just finished reading an article in Automotive News about GM's new 4.5L Duramax turbo-diesel V8. It has a double overhead cam design with four valves per cylinder. It will develop at least 310hp and 520lb-ft of torque. It will be sold in all 50 states and will be the first GM engine that will use urea injection to control emissions of oxides of nitrogen (NOx).

According to the article, the engine's design reverses the flow of air and exhaust gases going in and out of the cylinder heads. On standard V8 engines, fuel and air enter on the side of the cylinder heads facing the inner part of the "V." The exhaust gases exit on the V's outside. In the new design, air enters the engine through ports in the outer portion of each cylinder head. The exhaust gases then exit inward between the cylinder heads and directly into a turbocharger.

They say this eliminates numerous parts, saves space and lets the engine make more efficient use of heat. All of that improves fuel economy and performance, reduces noise and lowers emissions. The new engine eliminates the bulky intake manifold, two heavy cast-iron exhaust manifolds and related parts such as gaskets, bolts, nuts, studs and most heat shields.

The new design could shave $350-600 off the cost of producing the engine by some estimates.

The new compact design also solved a space problem. GM wanted a V* diesel that could fit in the same space as the small block V* gasoline engine in the Chevrolet Silverado-GMC Sierra pickups, and in the Chevrolet Tahoe/GMC Yukon SUVs. Since it is narrower than a regular diesel of the same displacement, the new engine fit.

The engine performance is apparently also impressive. Some GM bigshots (aka decison makers) took it for a test drive on the GM Milford Proving Grounds. They were amazed at how smooth, quiet and powerful the new diesel ran.

The top brass approved the new diesel engine for GM's light-duty trucks. It is scheduled for production in 2009 at a revamped plant in Tonawanda, N.Y.

For all its worth, I'm an engineer (Industrial) but I need to see things visually more or less, so when "gear-heads" start talking (or writing) its somewhat difficult to follow exactly what they are talking about. All in all, sounds like the new Duramax will be evolutionary.

[SteveH]

I've read about it also. Sounds very interesting, and I wish it were available now, as I'm in the market for a new truck, but can't aford nor do I need a big 3/4 ton diesel.

The things about the new diesel that concerns me is the reliability, and cost to repair. The cylinder heads as I remember are aluminum, and they are built in such a way that they now are one piece, and perform the funcions that used to be done by the cyclinder head, intake manifold, and exhaust manifold. What do you suppose that puppy costs if you have to replace one of them? Also, how is an aluminum cylinder head going to hold up on a 22:1 compression diesel?

[byamcaravanner]

Originally Posted by Streamer1

...For all its worth, I'm an engineer (Industrial) but I need to see things visually...

Here ya go!

I can't wait to see this baby in action!

[silverback]

I've been following this too and like what I'm seeing. Then again I've only got 57K on my current DMAX so it will be a while. I'll let you guys test it out first.
-KL

[moosetags]

I'm pleased and impressed. I'm about 2-3 years out on a new TV and want to stay with the 2500 Suburban. Hopefully, this new Duramax will be available in the '09 or '10 Sub.