What is the Ecotec's final frontier? So far, unknown; but we'll be looking to the track in 2002 for the answers to that question.
Ecotec Building Blocks
The Ecotec's outstanding feature to performance enthusiasts will undoubtedly be its impressive strength. GM Racing dyno tests confirm an otherwise bone-stock Ecotec is capable of a reliable 350 hp with forged rods and pistons (and a bunch of nitrous or boost). Add a billet crank, minor head reinforcing, and cylinder O-rings, and breathed-on turbo Ecotecs will live to race many times at 650 hp. Re-sleeve the block and 800-1,000 usable horsepower appears feasible with the right fuel.
The lightweight, low-friction Ecotec powerplant is built around a strong and compact 86mm-bore block manufactured with the lost-foam casting technique (they pack sulfur casting sand around Styrofoam molds shellacked with ceramic, then inject molten aluminum into the foam, which is vaporized into recoverable gas as the metal replaces it.) Flanged, thin-wall iron cylinder sleeves press-fit into a semi-floating aluminum support structure/core. The Ecotec block is supported by a massive die-cast aluminum girdle/main cap assembly and structural oil pan designed to impart rigidity for improved longevity and low noise, vibration, and harshness (NVH). The main-cap structures are each supported with six fasteners. Extra-thick main bearings resist the differential thermal expansion of the nodular-iron aerodynamic crank and aluminum block.
GM casts all Ecotec blocks with passages for piston-cooling jets and an oil cooler usable for potential high-output turbocharged applications. The fully-boxed block requires no windage tray, even on GM Racing 650+hp drag motors. An auxiliary chain drives the water pump and optional balance shafts from the crank.
To avoid potential hot spots, pressure-cast non-squish dished 9.5:1 pistons negate the need for any valve pockets; for high compression applications, flat-topping the pistons produces a 10:1 compression ratio. The top ring is a symmetrical, barrel-faced moly-coated design that fits in an anodized groove below a super-thin 3mm top ring land for low crevasse volume and reduced emissions. The pistons deliver power through full-floating pins and powder-metal or forged connecting rods.
GM designed the twin-cam head for low-friction hydraulic roller finger-followers, proven effective and reliable to 9,500 rpm in GM Racing's Ecotec drag engine program. Head fastener placement permits cylinder head R&R without cam removal. The cams are driven directly off the crank by a chain, with the design protected for possible future variable cam phasing. The finger-follower design permits a lightweight narrow profile and reduced valve angles of 18 and 16 degrees. GM engineers used the port tumble ratio to balance full and part-load combustion without need for variable-length intake runners. Port injectors mount in the head itself for optimal spray geometry, and the design is also protected for possible future direct injection-gasoline.
Ecotec engine management uses a speed-density port-EFI design with direct coil-on plug ignition. An integral compression-sense ignition module eliminates the need for a cam-position sensor.
The current 2.2-liter version of the Ecotec is available in the Saturn L-Series and VUE Sport Utility, the Olds Alero and Pontiac Grand Am, the Pontiac Sunfire and Chevy Cavalier, and in Opel/Vauxhall's Astra, Zafira, Speedster, and Vectra. GM's SAE paper on the Ecotec's development makes it clear GM designed the engine with plans to introduce it in additional applications, configurations, and displacements.