Originally Posted by Autoblog

Mark your calendars, because we're calling today a watershed moment for the advancement of diesel's acceptance in the U.S. General Motors has just announced a new 4.5L V8 Duramax turbo-diesel powerplant it plans to use in the Chevy Silverado and GMC Sierra half-ton pickups, as well as the HUMMER H2. The new oil burner is expected to produce at least 310 horsepower and 520 ft-lbs. of torque. It features dual-overhead cams, four valves per cylinder, a variable-vane turbocharger and aluminum cylinder heads with integrated manifolding that helps keep the overall package small enough to fit in the same space as the automaker's small-block gas V8s.

That's right, just imagine the possibilities. Wherever GM uses a small-block V8 gas engine, it could potentially use the 4.5L V8 Duramax diesel. In a few years we could be driving diesel Impalas, diesel Camaros, maybe even a diesel Corvette! To quote GM's press release, the engine's small size gives it "the flexibility to introduce this engine in a wide variety of vehicle applications should there be future market demand." Indeed.

GM estimates that the engine will improve fuel efficiency by 25%, reduce CO2 emissions by 13% and decrease particulate and NOx emissions by at least 90% in its GMT900 pickups and the HUMMER H2. Whoever said the HUMMER H2 was on its way out will likely be proven incorrect after this engine debuts. Scheduled to be built at the GM Tonawanda engine plant outside Buffalo, NY, the 4.5L V8 Duramax diesel will be 50-state emissions compliant and meet 2010 diesel emissions standards, as well. GM claims its new diesel will also have NVH (Noise, Vibration and Harshness) levels approaching those of today's current gas V8s, though we'll have to wait and see if that wish comes true. That wait should end in a couple of years, as the automaker states the engine will be available in Silverado, Sierra and H2 models built after 2009.


GM Press Release
TONAWANDA, N.Y. – General Motors Corp. will introduce a new, state-of-the-art 4.5L V-8 Duramax turbo-diesel that improves engine fuel efficiency by 25 percent, reduces CO2 emissions by 13 percent and cuts particulates and NOx emissions by at least 90 percent for North American light duty trucks and the HUMMER H2 built after 2009.

The premium V-8 diesel is expected to deliver class-leading torque, power and refinement while maintaining a significant fuel efficiency advantage over comparable-output gasoline engines.

The new dual-overhead cam, four-valve V-8 diesel engine will fit within the same space of a small-block V-8 gasoline engine. This compact size is made possible by using integral cylinder head exhaust manifolds, integral cam cover intake manifolds and a narrow block.

"This new GM light duty diesel is expected to become a favorite among customers who require excellent towing ability and fuel efficiency," said Tom Stephens, group vice president, GM Global Powertrain and Quality. "It will meet the stringent 2010 emissions standards, and it will be compliant in all 50 states, making it one of the cleanest diesel vehicles ever produced."

Environmental benefits of the new engine include a 13-percent reduction in CO2 versus gasoline engines, and at least a 90-percent reduction in particulates and NOx compared to diesel vehicles today. This will be GM's first engine to use a selective catalytic reduction NOx aftertreatment system with a diesel particulate filter to help achieve the Tier 2 Bin 5 and LEV 2 emissions standards.

Technical highlights of the engine include aluminum cylinder heads with integrated manifolding; a variable-vane turbocharger with intercooling; a Compacted Graphite Iron (CGI) block for a stronger and lighter engine base (compared to lower-strength aluminum or heavier grey cast iron); and fracture-split main bearing caps and connecting rods for a precise fit. An electronically controlled, ultra-high-pressure, common-rail fuel system is used, which has the ability to inject fuel five times per combustion event to control noise and emissions.

"This new V-8 is not only a clean diesel meeting the toughest emissions requirements in North America, it also delivers an effortless performance feel because of its high torque across the speed range," said Charlie Freese, executive director of GM Powertrain Diesel Engineering. "It is also significantly quieter than other diesels on the road today, with noise and vibration performance approaching gasoline V-8 levels."

Freese said the new V-8's compact size enables it to fit in the envelope of a gasoline small-block engine, which provides GM the flexibility to introduce this engine in a wide variety of vehicle applications should there be future market demand.

The premium V-8 diesel engine is expected to deliver class-leading refinement, horsepower and torque and fulfill multiple vehicle applications with ratings in excess of 310 horsepower and 520 lb-ft of torque.

GM (Opel, Saab, Vauxhall and GMDAT ) currently offers 17 diesel engine variants in 45 vehicle lines around the world. GM sells more than one million diesel engines annually, with products that offer a range of choices from the 1.3L four-cylinder diesel engine sold in the Opel Agila and Corsa, up to the 6.6L V-8 Duramax diesel sold in full-size vans, heavy duty pickups and medium duty trucks in the U.S.

GM first introduced the Duramax diesel 6.6L V-8 in the U.S. in the 2001 model year and since then, customer enthusiasm for this heavy duty diesel has been outstanding. In fact, GM's heavy duty pickup truck market share has jumped nearly tenfold in the six years that Duramax engines have been offered.

General Motors Corp. (NYSE: GM), the world's largest automaker, has been the annual global industry sales leader for 76 years. Founded in 1908, GM today employs about 280,000 people around the world. With global headquarters in Detroit, GM manufactures its cars and trucks in 33 countries. In 2006, nearly 9.1 million GM cars and trucks were sold globally under the following brands: Buick, Cadillac, Chevrolet, GMC, GM Daewoo, Holden, HUMMER, Opel, Pontiac, Saab, Saturn and Vauxhall. GM's OnStar subsidiary is the industry leader in vehicle safety, security and information services. More information on GM can be found at www.gm.com.

Link

Originally Posted by WECIV

One thing urks me though...no aluminium block. Why is that? Is it harder to do a aluminium block in a turbo diesel? Educate my ignorance. Thanks!!!

W

Originally Posted by WECIV

Why exactly do diesel blocks need to be stronger? Is it because they use pressure instead of spark to ignite the fuel? Thanks!

W

Originally Posted by WECIV

Why exactly do diesel blocks need to be stronger? Is it because they use pressure instead of spark to ignite the fuel? Thanks!

W

Originally Posted by WECIV

Gimme that mated to a M6 in a camaro!!!

W

Originally Posted by DrkPhynx

Diesels generally need to be stronger, and so far aluminum just is too soft. Same reason guys who run big boost use iron blocks. Diesels are all about boost, and super high pressure direct injected fuel, leading to much higher chamber pressures, so they need the iron block.

Plus iron blocks are always smaller. Notice how much they stressed packaging there. OHC is always much larger too - heads are bigger, and have to be stronger to support the cam(s), which again means bigger. This means the block has to be stronger, which also again means bigger, so that would be another reason for iron.

Gale Banks is working on an aluminum block turbo diesel, which he plans to spin to 7 grand. Can't wait to see that.

Originally Posted by camarolvr69

If they put it in a Colorado I would buy it....

Originally Posted by sb427f-car

Dunno why it can't be alum, other than a shitload of cost involved...



This has an alum. block, runs somewhere around 50#s and spins to about 5500 rpm.

Originally Posted by DrkPhynx

Cost and packaging. It's been said like a dozen times already.

Sure you can make it strong enough with aluminum, but to do it for a price low enough for the mass market is the key. And they are cramming a turbo OHC into the same space requirements as an NA OHV, that means they basically have to go iron. As said several times before......