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GM Quad 4 engine

Quad 4
Overview
Manufacturer Oldsmobile
Also called
  • Twin Cam
  • Quad OHC
Production 1987-2002
Combustion chamber
Configuration Straight-4
Displacement
  • 2,260.5 cc (137.94 cu in)
  • 2,392.3 cc (145.99 cu in)
Cylinder bore
  • 92 mm (3.6 in)
  • 90 mm (3.5 in)
Piston stroke
  • 85 mm (3.3 in)
  • 94 mm (3.7 in)
Cylinder block alloy Cast iron
Cylinder head alloy Aluminum
Valvetrain
Compression ratio
  • 9.5:1
  • 9.7:1
  • 10.0:1
Combustion
Fuel system Sequential multi-point fuel injection
Fuel type Gasoline
Oil system Wet sump
Cooling system Water-cooled
Chronology
Successor Ecotec engine

The engine family known as the Quad 4s was debuted to the public in the spring of 1987. The Quad 4 is a 2,260.5 cc (2.2605 L; 137.94 cu in) DOHC inline four-cylinder produced by General Motors' Oldsmobile division. Early television ads touting the new engine's abilities showed video of a limited edition Oldsmobile Calais (called the "GMO Quad 4") racing around city streets.

The Quad 4 name is derived from the engine's four-valve, four-cylinder layout. The engine was a modern design for its time, using a cast-iron block and an aluminum head. Even though belts were more popular for this purpose on OHC engines at the time, chains were used to time the camshafts to the crankshaft. The water pump is also driven by the timing chain. The Quad 4 was the first wholly domestic regular production DOHC four-cylinder engine designed and built by GM; the only prior DOHC four-cylinder engine offered by GM was the Cosworth Vega, which featured a DOHC head designed by Cosworth in England.

First released to the public as a regular production option for the 1988 Oldsmobile Cutlass Calais and Pontiac Grand Am, the engine's availability expanded to Buick in late 1988 and Chevrolet in 1990, after which it became a mainstay in GM's lineup until its cancellation after the 2002 model year.

Simultaneous to the engine's release in 1988, Oldsmobile attempted to further the Quad 4 name through highly publicized events featuring such cars as the Oldsmobile Aerotech. Another such event was the 1988 Indianapolis 500, when Oldsmobile was chosen to pace the race with a convertible version of their Cutlass Supreme, and a pre-production turbocharged Quad 4 was the engine of choice for their pace car. Although it was publicized in 1988 that the Quad 4 was forthcoming in a 180 bhp (130 kW) "HO", as well as a 250 bhp (190 kW) turbocharged version (the same engine that was in the pace car that year), GM never released this version as an option. Also, the engine in Oldsmobile Aerotech was a purpose-built, turbocharged example; it was solely meant to showcase the capability of the engine's design.


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Wikipedia

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