August 7, 2002
GM announces two new inline 4 and 5 cylinder engines
Pontiac, Michigan – GM has created two additional inline engines for mid-size pickup trucks: the Vortec 3500 inline five-cylinder and Vortec 2800 inline four-cylinder engines. Both engines are based on the current Vortec 4200 inline six-cylinder engine. They will be available in the 2004 Chevrolet Colorado and GMC Canyon. GM says they will provide the power of a V6 with the efficiency of an inline four cylinder engine.
With their common design, the new inline I-5 and I-4 engines feature the same all-aluminum construction, dual overhead camshafts and four-valves-per-cylinder technology as the Vortec 4200. The new engines also share the I-6’s high 10:1 compression ratio, electronic throttle control, exhaust cam phasing, coil-on-plug ignition, direct-mount accessories and easy maintenance features.
The cast aluminum four- and five-cylinder engine blocks and aluminum cylinder heads are produced using the same “lost foam” casting process as the Vortec 4200. This process allows more exact dimensional control while reducing machining efforts in oil galleries, coolant and other internal passages.
Overall, the new engines share 75 percent of their components with the Vortec 4200 and 89 percent of their components with each other. This provides customers with highly proven design features and enables GM to develop and introduce them more quickly and at a lower cost. Commonality also allows the engines to be manufactured more cost effectively and gives GM a unique ability to adjust production in response to changing market trends.
The Vortec 3500 I-5 is targeted to produce 215 horsepower and 225 lb-ft of torque. The Vortec 2800 I-4 is targeted to deliver 170 horsepower and 175 lb-ft of torque.
A major differentiating feature between the Vortec 3500 and 2800 engines is their dual balance-shaft system. The balance shafts offset secondary forces inherent to inline engines and help to provide smooth, quiet operation throughout the entire operating range.
Incorporated into housings on each side of the engine block, the balance shafts rotate in opposite directions of one another at twice engine speed, countering secondary forces generated by piston movement. They help eliminate vibrations that drivers and passengers might otherwise feel transmitted through the engine mounts to the steering wheel, seats, floor pan or instrument panel.
A rigid block structure and well-balanced crankshaft are also key to low noise, vibration and harshness. The Vortec 3500 crankshaft is optimally counterweighted for its five-cylinder design. Many of the same features used to control noise and vibration on the I-6 engine are found in the I-4 and I-5, such as isolated cam covers and acoustic foam treated induction manifolds, as well as attention to detail in the design process.
A unique manifold-mounted converter, a three-way catalyst constructed as part of the exhaust manifold, also sets the I-5 and I-4 engines apart from the I-6, and enables them to meet foreseeable future emissions requirements with no change in basic configuration. The new engines are designed to meet Federal Tier II / California Low Emission Vehicle (LEV II).
The new engines use a more powerful, next-generation powertrain control module (PCM), with a new GM common design. The PCM manages all engine and transmission functions and communicates with other electronic vehicle controls. The new PCM provides quicker response time and has flash programmable memory, allowing quick and easy reprogramming to accommodate new features and updates. GM is pursuing commonality in its PCMs to reduce engineering time and cost and to help bring new vehicles to market more quickly.