For the 2001 model year, GM will offer a new heavy-duty, or HD, pickup truck to the consumer. These new trucks will bring medium-duty technology to the light-duty truck user. This means more than the new distinct appearance, brought about mainly through the use of all-new sheetmetal from the doors forward. These trucks sport stronger frames and tougher drivetrains. The 2001 GMC Sierra and Chevrolet Silverado heavy-duty trucks are the results of GM's concerted efforts to build a market-leading heavy hauler, and these trucks have more than hit the mark. GM spared no effort on the design of the new trucks' chassis, suspension, and powertrain. The drivetrains have been vastly improved for the HD truck line. Here's a rundown of what's new in that department.
First off, the venerable Vortec 6000, 6.0L, small-block has been improved and produces 325 hp at 5,000 rpm and 360 lb-ft of torque at 4,000 rpm. This means 70 hp and 40 lb-ft more than the 5.7L (350-cid) engine it replaces. But GM didn't stop there. The new HD trucks will be offered with new-generation big-block and diesel engines too.
The big-block is the Vortec 8100 - an 8.1L or a 494-cid motor, the most technologically advanced big-block ever offered by GM. This motor has a 4-1/4-inch bore and a 4-3/8-inch stroke. This powerful new Rat motor produces 340 hp at 4,200 rpm and 455 lb-ft of torque at 3,200 rpm. The Vortec 8.1L engine incorporates advancements such as Teflon-coated pistons to reduce friction and stainless steel exhaust manifolds. For durability, the new engine has forged steel rods, a four-bolt main block, a nodular iron crankshaft, and hydraulic roller valve lifters that roll atop a steel camshaft. The aluminum intake manifold boasts equal-length runners; a sequential multiport fuel injection system delivers the fuel; and the ignition system is a coil-near-plug setup.
For those who like diesel motors, GM will offer the all-new Duramax 6600 (6.6L or 402-cid) mill. This new engine is compact for a diesel but offers more torque and horsepower than the competition's current diesel line. This beast of an engine produces 300 hp at 3,100 rpm and an astounding 520 lb-ft of torque at a leisurely 1,800 rpm. The Duramax is an all-new design with features that include: high-swirl aluminum cylinder heads with four valves per cylinder; a state-of-the-art Bosch fuel-injection system; a nitrided forged-steel crankshaft; and a single turbo mounted in the engine's V. The oil-burner also boasts a gear-driven camshaft that opens hydraulic roller lifters, an integral oil cooler, a gear-driven water pump, and pistons that are cooled with oil sprayed from small jets located on the lower segment of the cylinder walls. It's a true performance engine that just happens to be a diesel.