4 Cylinder Models
Engine Technical Data


Information taken from Rover Workshop Manual.

Air cleaner and silencer (single carburettor models)
Make AC Delco
Type Rnewable paper element
Air cleaner and silencer (twin carburettor models)
Make Cooper
Type Rnewable twin elements
Auxiliary drive unit
Auxiliary drive unit Oil pump, distributor and fuel pump
Type of drive Duplex chain
End-float of drive shaft 0.002 to 0.006 in (0.05 to 0.15 mm)
Camshaft
Drive Two duplex endless chains
Diameter of journals 1.125 in (2.85 mm)
Thrust taken No.1 bearing cap
Camshaft bearings
Type Shell - steel shell lined with white metal
Number of bearings 6
Bearing clearance 0.008 to 0.0028 in (0.020 to 0.070 mm)
Bearing nip 0.0015 to 0.0025 in (0.014 to 0.060 mm)
Carbuerettor - Single
Type SU HS6
Needle RN
Jet size 0.100 in (2.5 mm)
Float level 1/8 to 3/16 in (3.0 to 4.5 mm)
Idling speed 600/650 rpm
Carbuerettor - Twin
Type SU HD8
Needle U1
Jet size 0.125 in (3.0 mm)
Float level 7/16 (11 mm) in shut-off
Idling speed 700/750 rpm
Chains and chainwheels
Chain type Duplex endless
Number of pitches  
Bottom crankshaft to intermediate 74
Upper intermediate to camshaft 78
Chain tensioners 2, Reynolds hydraulic
Vibration dampers 2
Connecting rod
Type 'H' section forging
Length between centres 5.781 in (197.5 mm)
Big end bearings Detachable, lead-bronze steel shell positioned by tab
Bearing clearance 0.0008 to 0.0023 in (0.020 to 0.058 mm)
End-float connecting rod on crankpin 0.004 to 0.10 in (0.10 to 0.25 mm)
Bore diameter of little end bush 1.000 in (25.40 mm)
Connecting rod bearing nip 0.002 to 0.004 in (0.05 to 0.10 mm)
Crankshaft and bearings
Balance 1/3 oz/inches
Number of main journals 5
Width of main journals 1.375 in (40 mm)
Nominal diameter of crank journals: main bearings 2.5 in (63.50 mm)
Nominal diameter of crank journals: big end bearings 2.0 in (50.80 mm)
Width of crankpin 0.969 in (24.5 mm)
Thrust taken Thrust washers on No.4 main bearing
End-float 0.002 to 0.006 in (05050 to 0.15 mm)
Type Lead-bronze steel shell positioned by tab
Bearing clearance 0.001 to 0.0025 in (0.025 to 0.063 mm)
Bearing nip 0.004 to 0.006 in (0.10 to 0.15 mm)
Crankshaft damper 'Holset' Harmonic
Cylinder block
Type Monobloc, integral with crankcase. Stamped Z, A, B, C or D to denote standard piston grade
Cylinder reboring limit 0.040 in (1.00 mm)
Flywheel
Run-out permissible 0.002 in (0.05 mm)
Number of teeth on starter ring 93
Markings  
TDC When opposite pointer, No.1 piston is at top dead centre.
EP When opposite pointer, No.1 exhaust valve should be fully open 4 degrees on single carburettor engines and six degrees on twin carburettor engines. When opposite pointer with both valves closed, indicates firing point of No.1 cylinder
Oil filter
Details AC No. 7965022, Type SC
Pistons and rings
Type Bricomatic with combustion chamber in piston crown
Standard size Graded Z to D
Oversize 0.010 to 0.040 in (0.25 to 1.00 mm) - not graded
Clearance in bore measured at bottom of skirt at right angles to gudgeon pin 0.0015 to 0.0020 in (0.038 to 0.050 mm)
Compression rings 2
Scraper ring 1
Clearance in groove
Compression 0.001 to 0.003 in (0.02 to 0.07 mm)
Scraper 0.001 to 0.003 in (0.02 to 0.07 mm)
Gap when fitted
Compression ring - chrome 0.019 to 0.024 in (0.45 to 0.60 mm)
Scraper ring 0.014 to 0.019 in (0.35 to 0.48 mm)
Taper ring 0.017 to 0.022 in (0.43 to 0.55 mm)
Gudgeon pin outer diameter 1.000 in (25.4 mm)
Fit in little-end bush Light push fit
Location in piston By circlips
Tappets
Operation Camshaft operated direct on to valve tappets
Exhaust tappet clearance 0.013 to 0.015 in (0.33 to 0.38 mm) cold
Inlet tappet clearance 0.008 to 0.10 in (0.250 to 0.25 mm) cold
For adjusting clearrance, two shims per valve 26 sizes. Rnage 0.74 to 0.352 in (1.87 to 8.94 mm)
Valves
Valve face angle
Inlet
Exhaust
30 degrees 45 degrees
Stem diameter
Inlet
Exhaust
0.3145 in (7.98 mm) 0.3415 in (8.67 mm)
Stem clearance in guide
Inlet
Exhaust
0.001 to 0.003 in (0.02 to 0.07 mm) 0.002 to 0.004 in (0.05 to 0.10 mm)
Valve stem oil steals Robber 'O' ring in valve guides
Valve lift 0.370 in (9.40 mm)
Head diameter
Inlet
Exhaust
1.654 to 1.650 in (42.01 to 41.9 mm) 1.341 to 1.337 in (34.0 33.95 mm)
Valve guides
Bore diameter
Inlet
Exhaust
0.315 in (8.00 mm) 0.3438 in (8.73 mm)
Bore length
Inlet
Exhaust
2.525 to 2.531 in (64.13 to 64.28 mm) 2.525 to 2.531 in (64.13 to 64.28 mm)
Valve seats
Material
Inlet
Exhaust
Bricronium Brimochrome
Angle
Inlet
Exhaust
30 degrees 46 degrees
Seat width
Inlet
Exhaust
0.35 to 0.55 in (0.88 to 1.39 mm) 0.045 to 0.065 in (1.14 to 1.65 mm)
Valve springs
Type - single carburettor engines Inner and outer in pairs, interference fit
Type - twin carburettor engines Inner and outer, non-interference fit
Free length - single carburettor engines  
Free length - inner 1.960 in (49.78 mm)
Free length - outer 2.190 in (55.60 mm)
Active coils - inner 6
Active coils - outer 5.5
Fitted length and load - inner 1.443 in at 32.39 lb + 1.62 lb (36.65 mm at 14.84 mkg + 0.78 mkg)
Fitted length and load - outer 1.827 in at 59.53 lb + 3.00 lb (46.41 mm at 27.00 mkg + 1.36 mkg)
Free length - twin carburettor engines  
Free length - inner 1.921 in (48.79 mm)
Free length - outer 2.27 in (57.66 mm)
Active coils - inner 6
Active coils - outer 5.5
Fitted length and load - inner 1.443 in at 32.80 lb + 1.69 lb (36.65 mm at 14.88 mkg + 0.76 mkg)
Fitted length and load - outer 1.827 in at 73.00 lb + 3.65 lb (46.41 mm at 33.10 mkg + 1.66 mkg)