67HEAVEN
01-31-08, 11:46 AM
GM's manifold-free V-8 diesel
by RICHARD RUSSELL
From Thursday's Globe and Mail
January 31, 2008 at 12:00 AM EST
And now for something completely different — an internal combustion engine with no manifolds.
The fertile minds at GM engineering have set automotive tongues wagging with news of a new V-8 diesel engine with no intake or exhaust manifolds.
The 4.5-litre Duramax diesel, slated for production at GM's Tonawanda, N.Y., engine plant next year, will be used in light-duty pickups and the Hummer H2. GM says it will be one of the most powerful, low-emitting and package-efficient light-duty V-8 diesel engines in the world.
By incorporating intake and exhaust functions within the valley of the turbocharged engine, engineers were able to eliminate the bulky exterior exhaust manifolds, allowing the twin-cam, four-valve diesel to fit within the same envelope as the compact, small-block V-8 gasoline engine. This opens up a wide range of applications previously unavailable with a diesel.
http://images.theglobeandmail.com/archives/RTGAM/images/20080131/wh-howDuramax-0131/how_duramax31wh.jpg (http://images.theglobeandmail.com/archives/RTGAM/images/20080131/wh-howDuramax-0131/how_duramax31whbig.jpg)
Enlarge Image (http://images.theglobeandmail.com/archives/RTGAM/images/20080131/wh-howDuramax-0131/how_duramax31whbig.jpg)
One of the most powerful, low-emitting and package-efficient light-duty V-8 diesel engines in the world, the 4.5-litre Duramax diesel will be used in light-duty pickups and the Hummer H2 (General Motors)
The exhaust ports of the aluminum cylinder heads face inward, meaning the turbocharger, exhaust gas recirculation cooler and catalyst can all be mounted between the heads.
The new Duramax also does away with conventional intake manifolds as well. Intake ports are internal and, instead of being arrayed along the length of the head, they get their pressurized air/fuel mix directly through the top of the covers for the dual overhead camshafts.
GM says no compromises were necessary in arriving at the ultracompact design. At 310 horsepower and 520 lb-ft of torque, it has class-leading power. That compares with 365 hp and 660 lb-ft from the 46-per-cent-larger, current Duramax V-8.
The new 4.5-lire engine boasts 25 per cent greater fuel efficiency while reducing CO2 emissions by 13 per cent and particulate and NO2 emissions by at least 90 per cent, allowing it to meet the ultrastringent 2010 emission standards in all states and provinces. This is made possible by a new type of catalyst, an after-treatment system and a particulate filter.
Compared with conventional 90-degrees of separation, the cylinder banks of the new Duramax are splayed at 72 degrees to reduce overall width. Because of the inherent imbalance of the narrow angle, a balance shaft is employed. The engine will also boast a new E86 engine controller and a closed-loop cylinder-pressure monitoring system to be introduced in Europe next year on a new 2.9-litre V-6 turbo-diesel.
The aluminum cylinder heads are two-tiered internally with the intake and exhaust routes separated not only from each other, but also the water jacket and chain-driven valve-gear.
The innovation doesn't end with the heads. They sit atop a compacted graphite iron (CGI) block with a variable geometry turbo and intercooler between them. An electronic ultra-high-pressure (29,000 psi) common-rail injection system is utilized.
To cut down on the noise associated with the powerful combustion of a diesel engine, the injection system will introduce fuel five times during each combustion event. GM says the new Duramax is significantly quieter than other diesels as a result and the system also contributes to the reduced exhaust emissions.
The new Duramax will be available in light-duty Chevrolet and GMC trucks and the Hummer H2 built after 2009. The company says more details will be available once it has completed filing a number of patents.
SOURCE - The Globe and Mail (http://www.globeauto.com/servlet/story/RTGAM.20080131.wh-howDuramax-0131/GAStory/specialGlobeAuto/home)
by RICHARD RUSSELL
From Thursday's Globe and Mail
January 31, 2008 at 12:00 AM EST
And now for something completely different — an internal combustion engine with no manifolds.
The fertile minds at GM engineering have set automotive tongues wagging with news of a new V-8 diesel engine with no intake or exhaust manifolds.
The 4.5-litre Duramax diesel, slated for production at GM's Tonawanda, N.Y., engine plant next year, will be used in light-duty pickups and the Hummer H2. GM says it will be one of the most powerful, low-emitting and package-efficient light-duty V-8 diesel engines in the world.
By incorporating intake and exhaust functions within the valley of the turbocharged engine, engineers were able to eliminate the bulky exterior exhaust manifolds, allowing the twin-cam, four-valve diesel to fit within the same envelope as the compact, small-block V-8 gasoline engine. This opens up a wide range of applications previously unavailable with a diesel.
http://images.theglobeandmail.com/archives/RTGAM/images/20080131/wh-howDuramax-0131/how_duramax31wh.jpg (http://images.theglobeandmail.com/archives/RTGAM/images/20080131/wh-howDuramax-0131/how_duramax31whbig.jpg)
Enlarge Image (http://images.theglobeandmail.com/archives/RTGAM/images/20080131/wh-howDuramax-0131/how_duramax31whbig.jpg)
One of the most powerful, low-emitting and package-efficient light-duty V-8 diesel engines in the world, the 4.5-litre Duramax diesel will be used in light-duty pickups and the Hummer H2 (General Motors)
The exhaust ports of the aluminum cylinder heads face inward, meaning the turbocharger, exhaust gas recirculation cooler and catalyst can all be mounted between the heads.
The new Duramax also does away with conventional intake manifolds as well. Intake ports are internal and, instead of being arrayed along the length of the head, they get their pressurized air/fuel mix directly through the top of the covers for the dual overhead camshafts.
GM says no compromises were necessary in arriving at the ultracompact design. At 310 horsepower and 520 lb-ft of torque, it has class-leading power. That compares with 365 hp and 660 lb-ft from the 46-per-cent-larger, current Duramax V-8.
The new 4.5-lire engine boasts 25 per cent greater fuel efficiency while reducing CO2 emissions by 13 per cent and particulate and NO2 emissions by at least 90 per cent, allowing it to meet the ultrastringent 2010 emission standards in all states and provinces. This is made possible by a new type of catalyst, an after-treatment system and a particulate filter.
Compared with conventional 90-degrees of separation, the cylinder banks of the new Duramax are splayed at 72 degrees to reduce overall width. Because of the inherent imbalance of the narrow angle, a balance shaft is employed. The engine will also boast a new E86 engine controller and a closed-loop cylinder-pressure monitoring system to be introduced in Europe next year on a new 2.9-litre V-6 turbo-diesel.
The aluminum cylinder heads are two-tiered internally with the intake and exhaust routes separated not only from each other, but also the water jacket and chain-driven valve-gear.
The innovation doesn't end with the heads. They sit atop a compacted graphite iron (CGI) block with a variable geometry turbo and intercooler between them. An electronic ultra-high-pressure (29,000 psi) common-rail injection system is utilized.
To cut down on the noise associated with the powerful combustion of a diesel engine, the injection system will introduce fuel five times during each combustion event. GM says the new Duramax is significantly quieter than other diesels as a result and the system also contributes to the reduced exhaust emissions.
The new Duramax will be available in light-duty Chevrolet and GMC trucks and the Hummer H2 built after 2009. The company says more details will be available once it has completed filing a number of patents.
SOURCE - The Globe and Mail (http://www.globeauto.com/servlet/story/RTGAM.20080131.wh-howDuramax-0131/GAStory/specialGlobeAuto/home)