BMW M30

BMW M30 engine
Overview
Production	1968–1995
Layout
Configuration	Straight-6
Displacement	2,494 cc (152 cu in) 2,788 cc (170 cu in) 2,986 cc (182 cu in) 3,210 cc (196 cu in) 3,295 cc (201 cu in) 3,430 cc (209 cu in)
Cylinder bore	86.0 mm (3.4 in) 89.0 mm (3.5 in) 92.0 mm (3.6 in)
Piston stroke	71.6 mm (2.8 in) 80.0 mm (3.1 in) 86.0 mm (3.4 in) 88.0 mm (3.5 in)
Cylinder block material	Cast iron
Cylinder head material	Aluminium
Valvetrain	SOHC
Combustion
Fuel type	Petrol
Chronology
Predecessor	BMW M20
Successor	BMW M50

The BMW M30 is a SOHC straight-six petrol engine which was produced from 1968 to 1995. With a production run of 27 years, it is BMW's longest produced engine and was used in many car models.

The first models to use the M30 engine were the BMW 2500 and 2800 sedans. The initial M30 models were produced in displacements of 2.5 litres (2,494 cc) and 2.8 litres (2,788 cc). Larger displacement versions were introduced over time, with the largest version being 3,430 cc (209.3 cu in), which was sometimes badged as "3.5 litres".^[1] As per the BMW M10 four-cylinder engine from which the M30 was developed, the M30 has an iron block, an aluminium head and an overhead camshaft with two valves per cylinder.

The engine was given the nicknames of 'Big Six' and 'Senior Six', following the introduction of the smaller BMW M20 straight-six engine in the late 1970s. The M30 was produced alongside the M20 throughout the M20's production, and prior to the introduction of the BMW M70 V12 engine in 1987, the M30 was BMW's most powerful and largest regular production engine.

Following the introduction of the BMW M50 engine in 1990, the M30 began to be phased out.

Ward's have rated the M30 as one of the "Top Engines of the 20th Century".^[2]