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]

Engine dimensions — 548 cc (33.4 cu in) inline three-cylinder
Bore — 62.3 mm (2.45 in)
Stroke — 60.0 mm (2.36 in)
Fuel type — Unleaded regular gasoline

Versions

Displacement — 796 cc (48.6 cu in)
Bore — 65 mm (2.56 in)
Stroke — 80 mm (3.15 in)
Engine type — Inline three-cylinder SOHC 6 valves
Power — 33 kW (45 PS; 44 hp) at unknown rpm

This was built only for the Taiwanese market Mitsubishi Towny (Minica) and Minicab 800, from 01.87 - 11.88. Most specifications are unknown.

Displacement — 657 cc (40.1 cu in)
Bore — 65 mm (2.56 in)
Stroke — 66 mm (2.6 in)
Fuel type — Unleaded regular gasoline

Displacement — 1,061 cc (64.7 cu in)
Bore — 65 mm (2.56 in)
Stroke — 80 mm (3.15 in)
Engine type — Inline four-cylinder SOHC
Power — 43 kW (58 PS; 58 hp) JIS at 5,500 rpm
Torque — 9.1 kg⋅m (89 N⋅m; 66 lb⋅ft) at 3,500 rpm^[4]

Of the same dimensions as the 3G82 but with a fourth cylinder, this was built in Taiwan by CMC (China Motor Corporation). Used in the Mitsubishi Varica (LWB version of fourth generation Mitsubishi Minicab).

Wikimedia Commons has media related to Mitsubishi 3G8 engines.

• List of Mitsubishi engines