4 Cylinder Models Engine Specifications
(Twin 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 - UK and NADA 10:1
Compression ratio - other 9:1
Brake horsepower
Gross
10:1 compression ratio 9:1 compression ratio
124 at 5,000 rpm 117 at 5,500 rpm
Installed
10:1 compression ratio 9:1 compression ratio
114 at 5,500 rpm 107 at 5,500 rpm
Maximum torque
Gross
10:1 compression ratio 9:1 compression ratio
132 lb/ft (18.2 mkg) at 4,000 rpm 125 lb/ft (17.2 mkg) at 3,750 rpm
Installed
10:1 compression ratio 9:1 compression ratio
126 lb/ft (17.3 mkg) at 3,500 rpm 120 lb/ft (16.5 mkg) at 3,250 rpm
Maximum BMEP, Installed
10:1 compression ratio 157 lb/sq.in at 3,500 rpm
9:1 compression ratio 150 lb/sq.in at 3,250 rpm
Compression pressure at cranking speed (200 rpm)
10:1 compression ratio 190 lb/sq.in minimum
9:1 compression ratio 160 lb/sq.in minimum
Pistons
Speed 3,100 ft/minute at maximum bhp
RPM
Maximum 6,250
Spark plugs
10:1 compression ratio Champion N6Y - 14 mm with supressed cables and waterprrof covers
9:1 compression ratio
Point gap 0.025 in (0.70 mm)
Ignition timing (static - full retard)
10:1 compression ratio minimum 100 octane fuel 6 degrees BTDC
9:1 compression ratio, minimum 95 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 14 degrees BTDC
Inlet closes 46 degrees ABDC
Exhaust opens 44 degrees BBDC
Exhaust closes 16 degrees ATDC
No. 1 exhaust valve peak 104 degrees BTDC