4 Cylinder Models Engine Specifications
(Single Carburettor)

Information taken from Rover workshop manual.

Engine
Type Water cooled, overhead camshaft
Number of cylinders Four
Bore 3.375 in (8.57 cm)
Stroke 3.375 in (8.57 cm)
Capacity 120.8 cu/in (1978cc)
Compression ratio - standard 9:1
Compression ratio - for certain exports 7.5:1
Brake horsepower
Gross
9:1 compression ratio 7.5:1 compression ratio
99 at 5,000 rpm 87.5 at 5,000 rpm
Installed
9:1 compression ratio 7.5:1 compression ratio
90 at 5,000 rpm 80 at 5,000 rpm
Maximum torque
Gross
9:1 compression ratio 7.5:1 compression ratio
121 lb/ft (16 mkg) at 3,600 rpm 113 lb/ft (15 mkg) at 3,500 rpm
Installed
9:1 compression ratio 7.5:1 compression ratio
113 lb/ft (15.5 mkg) at 2,750 rpm 106 lb/ft (14.8 mkg) at 2,500 rpm
Maximum BMEP, Installed
9:1 compression ratio 141 lb/sq.in at 2,750 rpm
7.5:1 compression ratio 132 lb/sq.in at 2,500 rpm
Compression pressure at cranking speed (200 rpm)
9:1 compression ratio 160 lb/sq.in minimum
7.5:1 compression ratio 120 lb/sq.in minimum
Pistons
Speed 2,810 ft/minute at maximum bhp
RPM
Maximum 6,000
Spark plugs
9:1 compression ratio Champion N9Y - 14 mm with supressors and waterproof covers
7.5:1 compression ratio Champion N5 - 14 mm with supressors and waterproof covers
Point gap 0.025 in (0.70 mm)
Ignition timing
9:1 compression ratio, 95-97 octane fuel 4 degrees BTDC
7.5:1 compression ratio, 79-93 octane fuel 6 degrees BTDC
Firing order (both compressions) 1 - 3 - 4 - 2
Distributor
Contact breaker gap 0.014 to 0.016 in (0.35 to 0.40 mm)
Valve timing
Inlet opens 18 degrees BTDC
Inlet closes 42 degrees ABDC
Exhaust opens 48 degrees BBDC
Exhaust closes 12 degrees ATDC
No. 1 exhaust valve peak 108 degrees BTDC