BMW M328

BMW M328 engine
Overview
Production	1936–1940
Layout
Configuration	Straight-6
Displacement	2.0 L (1,971 cc)
Cylinder bore	66 mm (2.60 in)
Piston stroke	96 mm (3.78 in)
Cylinder block material	Aluminium
Cylinder head material	Aluminium
Valvetrain	OHV
Combustion
Fuel type	Petrol
Chronology
Predecessor	BMW M78
Successor	BMW M335

The BMW M328 is an overhead valve straight-six petrol internal combustion engine which was produced from 1936 to 1940. It was a high-performance development of the BMW M78 engine, and was produced alongside the M78. ^{[1] [2] [3]}

Unlike with the M78, the M328 has an aluminium cross-flow cylinder head ^[4] with hemispherical combustion chambers. ^[5]

The M328 was used in the BMW 328 and BMW 327/28 coupes. ^{[2] [3] [6]}

After World War II the engine was also licensed to Bristol Cars in the United Kingdom.

Design

The M328 has an unusual valvetrain design. The single camshaft is mounted low on the side of the engine block, and drives a rocker shaft on the intake side of the cylinder head through a set of vertical pushrods. A second set of horizontal pushrods run in tubes across the cylinder head to another rocker shaft on the exhaust side of the head. ^[5] This results in a valve layout similar to a DOHC engine.

With a bore of 66 mm (2.60 in) and a stroke of 96 mm (3.78 in), displacement is 1,971 cc (120.3 cu in); the same as its M78 predecessor. Fuel is supplied via three Solex 30 JF downdraught carburettors. ^[5]

The M328 engine has a compression ratio of 7.5:1 and produces 59 kW (79 bhp) at 5000 rpm. ^{[5] [7]}

Versions

Version	Displacement	Power	Torque	Years
M328	1,971 cc (120.3 cu in)	59 kW (79 bhp) at 5000 rpm	126 N⋅m (93 lb⋅ft) at 4000 rpm	1936–1940

Applications:

• 1936–1940 328
• 1937–1940 327/28
• 1947–1950 HH

See also

• BMW
• List of BMW engines

References

Notes

1. "BMW World - 6-Cylinder Engines". www.usautoparts.net. Archived from the original on 13 September 2010.
2. Lewin & Purves 2016.
3. Lewin 2004, pp. 191, 192, 251, 253, 257.
4. "1937 BMW 328". www.carfolio.com. Retrieved 23 August 2017.
5. "BMW 328 - the legendary roadster". www.bmwccn.no. Archived from the original on 3 January 2010.
6. Norbye 1984.
7. "1937 BMW 328". www.carfolio.com. Retrieved 24 August 2017.

Bibliography

• De Ste. Croix, Philip; Noakes, Andrew (September 2010). The Ultimate History of BMW (Hardcover). United Kingdom: Parragon Book Service Limited. ISBN   9781407549781.
• Gillies, Mark; Sedgwick, Michael (October 28, 2010). A-Z of Cars, 1945-1970 (Paperback). United Kingdom: Herridge & Sons Limited. ISBN   9781906133269.
• Hudock, Greg (October 14, 2012). BMW 3 Series - E36 Restoration Tips & Techniques (ebook). United Kingdom: Brooklands Books. ISBN   9781855209701.
• Lewin, Tony (December 25, 2004). The Complete Book of BMW. N.p.: MotorBooks International. pp. 191, 192, 251, 253, 257. ISBN   9781610592055.
• Lewin, Tony; Purves, Tom (2016). The BMW Century: The Ultimate Performance Machines (Hardcover). Motorbooks Press. ISBN   9780760350171 . Retrieved 21 January 2023.
• Norbye, Jan P. (1984). BMW, Bavaria's Driving Machines (Hardcover). Skokie, Illinois, United States: Random House Value Publishing, Publications International. ISBN   9780517424643.