

The bore and stroke of the engine both measure 86 mm (3.39 in), which engineers refer to as square.

The difference in displacement is achieved by variance in bore and stroke. All variations of 4B1 engine share the same engine block with a 96 mm bore pitch. Īll engines developed within this family have aluminium cylinder block and head, 4 valves per cylinder, double overhead camshaft layouts, and MIVEC continuous variable valve timing. The cylinder block and other basic structural parts of the engine were jointly developed by the GEMA companies, but the intake and exhaust manifolds, the cylinder head's intake and exhaust ports, and other elements related to engine tuning were independently developed by Mitsubishi. Although the basic designs of the various engines are the same, their exact specifications are individually tailored for each partner ( Chrysler, Mitsubishi, and Hyundai).

The Mitsubishi 4B1 engine is a range of all-alloy straight-4 piston engines built at Mitsubishi's Japanese "World Engine" powertrain plant in Shiga on the basis of the Global Engine Manufacturing Alliance (GEMA). Mitsubishi Sirius engine (Gasoline Engine) Direct acting DOHC, 16 valves, continuously variable MIVEC intake and exhaust valve timingįrom 140 to 409 PS (103 to 301 kW 138 to 403 bhp)įrom 14.5 to 53.5 kg⋅m (142 to 525 N⋅m 105 to 387 lbf⋅ft)
