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BMW M43B18 Engine Specifications

The BMW M43B18 is a 1.8 liters (1,796 cc, 109.6 cubic inches) straight-four, four-stroke cycle, naturally aspirated gasoline engine from the BMW M43-family. The engine was manufactured from 1993 to 1999 at the Steyr engine plant. The engine features a cast-iron cylinder block, a crankshaft with four counterweights and aluminum head with a chain-driven single overhead camshaft (SOHC) and two valves per cylinder (8 in total) with hydraulic tappets. It has an 84.0 mm (3.31 in) cylinder bore and 81.0 mm (3.19 in) piston stroke. Compression ratio rating is 9.7:1. This engine used a Multi Point Fuel Injection system (MPFI), the Bosch Motronic M 1.7 engine management system and a dual length intake manifold (BMW “DISA”). Redline is 6,200 rpm. The BMW M43B18 engine produced 115.6 PS (85.0 KW; 114.0 HP) at 5,500 rpm of maximum output power and 168.0 Nm (17.14 kgm; 124.0 ft-lb) at 3,900 rpm of peak torque. There was also a natural gas-powered (Compressed natural gas, CNG) version for the BMW 518g Touring (E34). This engien version produced 100.6 PS (74.0 KW; 99.2 HP) at 5,500 rpm of horsepower and 142.0 Nm (14.5 kgm; 104.8 ft-lb) at 3,900 rpm of torque.

The breakdown of the engine code is as follows:

M43 - Engine Family
B - Gasoline
18 - 1.8 Liter displacement

GENERAL TECHNICAL DATA

Engine model ..................... M43B18
Cylinder layout ..................... Four stroke, Inline-4 (Straight-4)
Fuel type ..................... Gasoline
Year of production ..................... 1993-1999
Total displacement ..................... 1.8 L, 1,796 cc (109.6 cubic inches)
Fuel system ..................... Multi Point Fuel Injection (MPFI)
Power adder ..................... None
Maximum power ..................... 115.6 PS (85.0 KW; 114.0 HP) at 5,500 rpm
CNG: 100.6 PS (74.0 KW; 99.2 HP) at 5,500 rpm
Maximum torque ..................... 168.0 Nm (17.14 kgm; 124.0 ft-lb) at 3,900 rpm
CNG: 142.0 Nm (14.5 kgm; 104.8 ft-lb) at 3,900 rpm
Firing order ..................... 1-3-4-2
Dimensions (L x H x W) ..................... -
Weight ..................... -

CYLINDER BLOCK

Cylinder block alloy ..................... Cast-iron
Compression ratio ..................... 9.7:1
Cylinder bore ..................... 84.0 mm (3.31 in)
Piston stroke ..................... 81.0 mm (3.19 in)
Number of piston rings (compression / oil) ..................... 2 / 1
Number of main bearings ..................... 5
Cylinder inner diameter (standard) ..................... 84.000-84.014 mm (3.3071-3.3076 in)
Piston skirt diameter (standard) ..................... 83.985 mm (3.3065 in)
Piston ring side clearance ..................... Top ..................... 0.020-0.200 mm (0.0008-0.0079 in)
Second ..................... 0.020-0.100 mm (0.0008-0.0039 in)
Piston ring end gap ..................... Top ..................... 0.200-1.000 mm (0.0079-0.0394 in)
Second ..................... 0.200-1.000 mm (0.0079-0.0394 in)
Oil ..................... 0.400-1.400 mm (0.0157-0.0551 in)
Crankshaft journal diameter ..................... 60.000 mm (2.3622 in)
Crankpin journal diameter ..................... 45.000 mm (1.7717 in)

CYLINDER HEAD

Valve Arrangement ..................... SOHC, chain-driven
Valves ..................... 8 (2 valves per cylinder)
Intake/Exhaust duration ..................... -
Valve head diameter ..................... INTAKE ..................... 42.000 mm (1.6535 in)
EXHAUST ..................... 36.000 mm (1.4173 in)
Valve steam diameter ..................... INTAKE ..................... 6.975-7.000 mm (0.2746-0.2756 in)
EXHAUST ..................... 6.960-7.000 mm (0.274-0.2756 in)

MAINTENANCE DATA

Oil system
Recommended engine oil ..................... SAE 0W-40, 5W-30, 5W-40
Oil type ..................... API SG or SF and better
Engine oil capacity (Refill capacity) ..................... 4.0 L (4.23 US. qt, 3.52 Imp. qt.)
Ignition system
Spark plug ..................... Bosch FGR7DQP, NGK BKR6EQUP
Spark plug gap ..................... 0.5 mm (0.0197 in)

VEHICLE APPLICATIONS

BMW 318i (E36) ..................... 1993-1999
BMW 518i (E34) ..................... 1994-1996
BMW 518g Touring (E34) ..................... 1995-1996
BMW Z3 1.8 ..................... 1996-1998

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