New GM V8 Diesel with intake manifolds integrated in cam cover
General Motors Corp. will introduce a new 4.5L V8 Duramax turbodiesel for North American light duty trucks and the HUMMER H2 built after 2009. The new dual-overhead cam, four-valve V8 diesel engine will fit within the same space of a small-block V8 gasoline engine. This compact size is made possible by using integral cylinder head exhaust manifolds, intake manifolds integrated in cam cover and a narrow block.
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 after-treatment 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 aluminium 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.
