BMC B-Series engine

Infobox Automobile engine


name = B-Series
manufacturer = BMC
type = in line 4
production = 1954–80
predecessor =
successor =
bore =
stroke =
displacement = 1.2 – 2.4 litres
length =
width =
height =
weight =
block = cast iron
head = cast iron
valvetrain = pushrod or overhead cam
fuelsystem =
fueltype = petrol & diesel versions
oilsystem =
coolingsystem = water
power =
torque =
compression =
fuelcon =
specfuelcon =
oilcon =
similar = The BMC B-series was a straight-4 internal combustion engine family, mostly used in motor cars, created by British company the British Motor Corporation (BMC), as a larger alternative to its A-series. Displacements ranged widely from 1.2 litres to 2.4 litres, the latter being an experimental six-cylinder variant. 1.5 litre and 1.8 litre displacements were most common. Petrol versions were produced in the greatest numbers, but diesel versions exist for both cars and marine applications.

The engine was of conventional construction with a one piece crankcase and cylinder block in cast iron with cylinder head also usually in cast iron. The sump was made from pressed steel. Early engines used a three-bearing crankshaft but later engines used five bearings. On all except the rare twin overhead camshaft variant the camshaft, which was chain driven and mounted low in the block, operated the overhead valves via pushrods and rocker arms. The two inlet ports in the non-crossflow cylinder head were shared between cylinders 1 + 2 and 3 + 4 and the three exhaust ports between cylinder 1, 2 + 3 and 4. Valve clearance was adjustable by screws on the rocker arms with access to the tappets by two side covers on the engine block, this feature being a hang over from side valve engine design.Fact|date=June 2008

Engine numbering

There were two series of engine numbers used; BMC changed the system at the end of 1956.

Early numbering system

Numbers were of the style "BP15GB" followed by a serial number, where:

* B = B series engine
* P = Pushrod
* 15 = capacity
* G = MG (for full list see Later numbering system below)
* The final letter is the version of the engine.

1957–70 numbering system

Numbers were of the style "15GB-U-H" plus a serial number, where:

* 15 = capacity
* G = MG (other letters were: A = Austin, B = Industrial, H = Miscellaneous, J = Commercial, M = Morris, R = Riley, V = Vanden Plas and W = Wolseley )
* B = B series engine
* U = Central gear change (other letters were: A = Automatic, M = Manumatic clutch, N = Column change, O = Overdrive and P = Police)
* H = High compression (alternatively L = Low compression)

1970 onwards numbering system

Numbers were simplified to "16 V" plus a serial number, where 16 represents the capacity and V = vertical, "i.e." longitudinal (in-line, not vee-arranged) engine with rear-wheel drive, and H = Horizontal, "i.e." transverse engine with front-wheel drive.Fact|date=June 2008

There was sometimes a country indicator after the first part of the code, "e.g." "18V-Z" was use for some United States (except California) MG MGB engines.

Engine Types

1.2 litre engines

The 1200 cc was the first version of the engine and appeared in the 1954 Austin A40 Cambridge and the 1954 Morris Cowley. The bore was 65.5 mm and the stroke 89 mm. The maximum power output was convert|40|bhp|abbr=on at 4300 rpm for the Austin and convert|42|bhp|abbr=on at 4500 rpm for the Morris.

* 1954–56 Morris Cowley
* 1954–56 Austin A40 Cambridge
* 1954–55 Nash Metropolitan 1200
* Massey-Harris Combine Harvester

1.5 litre engines

The 1.5 L (1489 cc) version was first used in 1953 in the MG Magnette ZA in twin carburettor version and in 1954 in the Morris Oxford and Austin Cambridge. In 1957 it was used in the original MGA. Output in twin carburettor form was 68 to 72 bhp (51 to 54 kW) and convert|55|bhp|abbr=on with a single carburettor. Bore was 73.025 mm (2.9 in) and stroke was 89 mm (3.5 in).

There was also a diesel version of this engine size. Power output was convert|40|bhp|abbr=on at 4,000 rpm and torque 64 lbf·ft at 1,900 rpm.

Applications:
* 1954–61 Morris Oxford Marks II, III, IV, & V
* 1956–59 Morris Cowley
* 1956–62 Nash Metropolitan 1500
* 1955–58 MGA
* 1953–61 MG Magnette ZA, ZB, & Mark III
* 1956–58 Austin A50 Cambridge
* 1958–61 Austin A55 Cambridge
* 1956–58 Wolseley 15/50
* 1957–65 Wolseley 1500
* 1958–61 Wolseley 15/60
* 1957–61 Morris Commercial J-type
* 1957–65 Riley 1.5
* 1959–61 Riley 4/68
* 1959–65 Rochdale Olympic
* 1956–61 Austin 152 & Morris J2 1/2-ton vans
* 1958–62 Morris Major Series I & II and Austin Lancer Series I & II
* 1957–63 Tempo Matador
* Hindustan Ambassador
* International Harvester "Metro-Mite" delivery truck
* Navigator 1500 marine engine
* 1958–60 TVR Grantura Mark I
* 1960–62 TVR Grantura Mark II & IIA
* Elva Courier

Twin-Cam engines

A special Twin-Cam (DOHC) version of the 1588 cc B-series engine was produced for the MGA. Output was 108 bhp (82 kW) at 6700 rpm in the high compression (9.9:1) version and 100 bhp (75 kW) in the optional low compression (8.3:1) version. The engine block was cast iron but the crossflow eight port cylinder head was of aluminium alloy. Drive to the twin camshafts was by chain from a gear driven half speed shaft running in the space that would have been occupied by the conventional camshaft. This engine gained a reputation for being unreliable in service, especially in the high compression version which needed high octane fuel, but this has now been largely overcome. The piston burning habits thought to be the result of ignition timing was later discovered to be due to a vibration induced lean burn situation involving the float bowls, easily correctable by flexibly mounting the carburettors.

A total of 2,111 cars were built, in both coupé and roadster versions.

A very few engines with the special displacement of 1762 cc were produced for racing purposes.

Applications:
* 1958–60 MGA Twin-Cam

1.6 litre engines

The engine was enlarged to 1.6 L (1588 cc) in 1958 by increasing the bore to 75.41 mm (3 in).

Applications:
* 1959–61 MGA 1600
* 1960–62 TVR Grantura Mark II, IIA
* Elva Courier Mark II

1.6 litre Mark II engines

The engine was enlarged to 1622 cc in 1961 with another bore increase, this time to 76.2 mm (3 in).

Applications:
* 1961–62 MGA Mark II
* 1961–69 Austin Cambridge A60
* 1961–71 Morris Oxford VI
* 1961–71 Wolseley 16/60
* 1961–69 Riley 4/72
* 1961–68 MG Magnette Mark IV
* 1961–67 Austin 152 & Morris J2 1/2-ton van
* 1974–78 Sherpa van
* 1962–64 Morris Major Elite
* 1963–66 Tempo Matador
* 1966–67 Hanomag Matador
* 1967–73 Hanomag F20, Hanomag F25, Hanomag F30, Hanomag F35
* 1970–73 Mercedes Benz L206, Mercedes Benz L306
* Navigator 1600 marine engine
* 1962–64 TVR Grantura Mark III

1.8 litre engines

The engine was enlarged again to 1.8 L (1789 cc) in 1962. Bore was 80.26 mm (3.2 in) and stroke was 88.90 mm (3.5 in). The engine at first had a 3 bearing crankshaft with a 5 bearing version appearing in 1964.

There was also a diesel version of this capacity, used in the Leyland Sherpa van, and built under license in Turkey for many years.

Applications:
* 1962–80 MGB
* 1964–75 BMC ADO17 ("Landcrab") Austin 1800
* 1967–72 BMC ADO17 ("Landcrab") Wolseley 18/85
* 1966–75 BMC ADO17 ("Landcrab") Morris 1800
* 1975–78 Princess 1.8
* 1971–78 Morris Marina 1.8
* 1964–67 TVR Grantura Mark III and IV
* 1974–78 Leyland Sherpa van
* 1973–75 Hanomag F20, Hanomag F25, Hanomag F30, Hanomag F35
* 1973–77 Mercedes Benz L207
* 1973–78 Mercedes Benz L307

2.4 litre engines

There was a 2433 cc six-cylinder unit, named "Blue Streak", which was used in the Australian Austin Freeway and Wolseley 24/80.

External links

* [http://www.co-oc.org/ Owners' club]
* [http://www.mgcars.org.uk/mgccz/technic/codeseng.pdf Full list of engine codes]
* [http://www.austin-rover.co.uk/index.htm?enginebseriesf.htm B series engine description at "the unofficial Austin Rover resource"]