FOR RELEASE: February 18, 2000

CONTACT(S): GM Powertrain Communications
(248) 857-0165

NEW VORTEC 8100 BUILDS ON GM'S HERITAGE OF V8 LEADERSHIP; PROVIDES POWERFUL PEROFRMANCE - ON LAND OR WATER

MIAMI - General Motors' new Vortec 8100 V8 gasoline engine builds on a rich history of V8 industry leadership, powering both trucks and boats in 2001. On land, the Vortec 8100 will be the new industry standard for gasoline engines in the heavy-duty pickup truck market. In water, two versions of this powerful engine will be available to several marine original equipment manufacturers (OEMs). "GM has a proud history of V8 engine leadership, dating to 1915 with the first U.S. mass-produced V8," said Arv Mueller, group vice president of GM Powertrain. "By developing a flexible V8 engine architecture such as the Vortec 8100, we are able to meet a broad spectrum of customer requirements including performance, fuel efficiency and overall comfort, whether for trucks or boats. Few companies can claim the ability of having versions of the same engine powering a boat, and the pickup truck towing the boat."

The 8.1-liter V8 engine will make its debut in the 2001 Chevrolet Silverado and GMC Sierra 2500HD/3500 series heavy-duty pickup trucks (available this fall). It offers 340 horsepower and 455 lb-ft of torque and will provide excellent tow/haul capabilities.

The engine can be mated to an all-new Series 1000 Allison 5-speed automatic transmission or to a new standard ZF 6-speed manual transmission. For marine application, the Vortec 8100 will be available in two versions - a standard 375-horsepower offering and an impressive 415-horsepower high-performance offering.

Vortec 8100 Development
GM Powertrain engineers used the proven Vortec 7400 as a basis for creating the Vortec 8100 and focused on only those improvements that would provide real customer benefits. As an example, while the Vortec 7400's same general envelope size was maintained, the engineers were still able to increase power and performance.

The larger displacement comes from the longer stroke (total length - 4.37 inches) used in the 8.1-liter. The same bore size was maintained. A 50 percent increase in ignition energy, a reduction of emissions and an improved idle quality are advantages obtained from the coil-near-plug ignition system.

Internally balancing the crankshaft led to a reduction in its stress by removing the counterweight from the flywheel. There's a new firing order that provides an additional seven percent decrease in crankshaft stress.

The cylinder heads have been redesigned to create replicated ports for the combustion chamber. This common-style porting and porting length minimizes the variation in torque from one cylinder to the next, producing a much smoother operating and cleaner engine.

Even-length runners in the intake manifold are used for each cylinder to create more even combustion and greater efficiency in the combustion process. The fuel rail system is part of the manifold itself, creating an integrated air/fuel module. The throttle body now sits front and center on the intake manifold, where it can distribute the air more efficiently and can also enhance engine package ergonomics.

The technological envelope of piston and ring design was expanded in order to allow the Vortec 8100 to provide its many best-in-class power, performance, reliability and durability benefits, as well as package-efficient size. The new pistons have a much shorter combustion height and a tighter ring pack than those in many other engines.

The engine uses cast stainless-steel exhaust manifolds, a first for GM 3/4-ton and 1-ton truck engines. This material withstands higher temperatures better than cast iron exhaust manifolds and is more durable and longer lasting. Cooling system enhancements include quick connections that replace compression fittings throughout the engine/transmission oil cooling system, for enhanced durability and easier assembly. Radiator hose ends are specially formed and provide tighter, more reliable and durable fits. Special beads on the hose inlets and outlets also ensure tight fits.

Marine Application
GM engines that are sold to the marine industry are designed from the beginning to meet both the vehicle and marine customer's requirements. Some of the specially designed marine features for the Vortec 8100 include the water pump, camshaft, cast-aluminum oil pan with baffle, marine external water crossover (no water in intake manifold), and a coating of the cast-aluminum oil pan to accept marine paint.

Because about 25 percent of GM's larger displacement engines are typically sold for marine use, much of the validation on the Vortec 8100 was done using the marine market's more severe-duty test parameters.

In one particular test, called the 'Marine Dock,' an engine is run at virtually wide-open throttle for 300 hours straight (60-minute cycle -- 55 minutes wide-open-throttle/5 minutes idle), further proving the considerable attention to quality built into every GM engine. This testing is more severe than the standard durability testing used for truck applications.

"Whether you are in a truck or boat, this powerful, efficient, low-maintenance Vortec 8100 engine will perform for years under the most demanding conditions," said Mueller.

GM Powertrain
GM Powertrain manufactures products for GM cars and trucks, but also has a strong outside sales activity to more than 25 customers. GM Powertrain sells engines, transmissions, castings, and components to non-GM OEMs such as AM General, Volvo, BMW, Daewoo and Isuzu. In addition, GM supplies engines to many industrial and marine OEMs. Marine OEMs include - Mercruiser, Volvo Penta, Indmar Products, Marine Power, Pleasurecraft Crusader, Flagship Marine, Panther Airboat, Panther Marine, and Kodiak.