The BMW M40 is an
SOHC
An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion cha ...
straight-four
A straight-four engine (also called an inline-four) is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft.
The vast majority of automotive four-cylinder engines use a straight-four layout (with the e ...
petrol engine
A petrol engine (gasoline engine in American English) is an internal combustion engine designed to run on petrol (gasoline). Petrol engines can often be adapted to also run on fuels such as liquefied petroleum gas and ethanol blends (such as ''E ...
which was produced from 1987–1994.
It served as
BMW's base model four-cylinder engine and was produced alongside the higher performance
BMW M42
The BMW M42 is a DOHC straight-four petrol engine which was produced from 1989-1996. It is BMW's first mass-production DOHC engine and was produced alongside the BMW M40 SOHC four-cylinder engine as the higher performance engine.
The M42 was rep ...
DOHC four-cylinder engine from 1989 onwards.
Compared with its M10 predecessor, the M40 uses a belt-driven camshaft,
and hydraulic tappets. Like the M10, the M40 uses an iron block and an aluminium head. Fuel injection for the E30 versions is
Bosch Motronic 1.3, and the E36 versions use
Bosch Motronic 1.7.
Following the introduction of the
BMW M43
The BMW M43 is an SOHC four-cylinder petrol engine which was produced from 1991-2002. The M43 powered base-model cars, while higher performance models at the time were powered by the BMW M42 and BMW M44 DOHC engines. The M43 was produced at the ...
engine in 1991, the M40 began to be phased out.
Versions
M40B16
The M40B16 is a version of the M40, which has a bore of and a stroke of .
It produces and .
Applications:
*1988–1994
E30 316i
*1990–1994
E36 316i
*1992–1993
Bertone Freeclimber 2
M40B18
The M40B18 is a version of the M40, which has a bore of and a stroke of .
It produces and .
Applications:
*1987–1994
E30 318i
*1988–1994
E34 518i
*1992–1993
E36 318i
See also
*
List of BMW engines
BMW has been producing engines for automobiles, motorcycles and aircraft since 1917, when the company began production of an inline-six aircraft engine. They have been producing automobile engines since 1933.
Motorcycle engines
Automotive ...
References
{{BMW automotive petrol engines: 1960s to 1980s
M40
Straight-four engines
Gasoline engines by model