Mitsubishi 3G8 engine

Mitsubishi 3G8 engine
Overview
Manufacturer	Mitsubishi Motors
Production	1987–present
Layout
Configuration	Straight-3
Displacement	548 cc (33.4 cu in) 657 cc (40.1 cu in) 796 cc (48.6 cu in) 1,061 cc (64.7 cu in)
Cylinder bore	62.3 mm (2.45 in) 65 mm (2.56 in)
Piston stroke	60 mm (2.36 in) 66 mm (2.60 in) 80 mm (3.15 in)
Cylinder block material	Cast iron
Valvetrain	SOHC, DOHC
Compression ratio	8.5:1, 9.8:1, 10.0:1
Combustion
Supercharger	Available 1987–1990
Turbocharger	with air-to-air intercooler (on 1989-1990 models)
Fuel system	Carburetor Electronic fuel injection
Fuel type	Gasoline
Cooling system	Water cooled
Output
Power output	22–47 kW (30–64 PS; 30–63 hp)
Torque output	41–96 N⋅m (30–71 lb⋅ft)

The Mitsubishi 3G8 engine is a range of three-cylinder powerplant from Mitsubishi Motors, introduced in the fifth generation of their Mitsubishi Minica kei car. In common with other contemporary engines in the class, it could be specified with many advanced technologies despite its diminutive size, including multi-valve cylinder heads and double overhead camshafts. The top-of-the-line Dangan ZZ variant was also the first kei car to benefit from turbocharging. In 1987 Mitsubishi was the first manufacturer to supercharge a kei vehicle, and in 1989 became the world's first production car to feature five valves per cylinder, ahead of similar developments by Bugatti, Audi, Ferrari and Toyota.^[1][2]

Its 3G81 three-cylinder engine has a displacement of 548 cc (33.4 cu in) and the 15-valve versions feature three intake valves and two exhaust valves incorporated into each cylinder. The valves are controlled by twin overhead camshafts through roller cam followers on finger rockers with hydraulic automatic lash adjusters. Gasoline is electronically injected through triple-jet nozzles (also a technological first). The water-cooled turbocharger operates through an air-to-air intercooler. The ignition timing advance is also controlled electronically, and a knock-sensing system is included.^[1]

Originally a 548 cc (33.4 cu in) engine, it was enlarged to 657 cc (40.1 cu in) in 1990 following changes in the class regulations. The four-cylinder 4A3 engine is derived from the 3G8, sharing a 72 mm (2.8 in) bore pitch.^[3]