BMW M328

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BMW M328
BMW 328 6-Zylinder-Motor.jpg
Manufacturer BMW
Production 1936-1940
Combustion chamber
Configuration Straight-6
Displacement 1,971 cc (120.3 cu in)
Cylinder bore 66 mm (2.6 in)
Piston stroke 96 mm (3.8 in)
Cylinder head alloy aluminum
Valvetrain OHV
Compression ratio 7.5:1
Fuel system Solex 30 JF
Power output 80 PS (59 kW; 79 hp)

The BMW M328 is a straight-6 OHV piston engine which was produced alongside the M78 from 1936 to 1940.[1] It was a high-performance development of the M78 engine, and was made for use in the BMW 328 sports car. An aluminium cylinder head with a hemispherical cross-flow combustion chamber was developed for this engine.[2]

The M328 had an unusual valvetrain design. While the camshaft was located in the block (as per OHV engines), the exhaust valves were controlled by a transverse pushrod from the intake valves.[2] This meant the valve layout is similar to a DOHC engine. With a bore of 66 mm (2.6 in) and a stroke of 96 mm (3.8 in), the displacement was 1971 cc, the same as M78 engine used in the BMW 326. Three Solex "30 JF downdraft" carburetors were used on the M328.[2]


Model Displacement Power Torque Year
M328 1,971 cc 51 kW (69 PS; 68 hp) 1936-1940


The M328 engine has a compression ratio of 7.5:1 and produces 80 PS (59 kW) at 5000 rpm.[2]



  1. ^ "BMW World - 6-Cylinder Engines". US Autoparts. 2007. Archived from the original on 2010-09-13. Retrieved 2012-06-13. 
  2. ^ a b c d "BMW 328 - the legendary roadster". BMW Car Club, Norway. Archived from the original on 2010-01-03. Retrieved 2008-08-30. 
  • Norbye, Jan P. (1984). BMW - Bavaria's Driving Machines. Skokie, IL: Publications International. ISBN 0-517-42464-9.