specifications for the 1275cc Rover Mini engine






EFI and carburettor versions 1990 to 2001






engine number prefix 12a2af53 carb






12a2ag01 carb






12a2ef77 EFI 91 on






Engine Type 1275cc no tappet covers
cup type welch plugs x 5 no tappet covers


Bore
2.780"




Stroke
3.204"




capacity of combustion chamber
21.4cc




b.m.e.p.





Bhp





Torque





Fuel System
leaded




Compression Ratio
8.8:1 carby 9.4:1 EFI




Firing Order
1 3 4 2




Valve Clearance (Inlet)
.012" thou




Valve Clearance (Exhaust)
.012" thou




Cylinder Head Tension
42 ft/lb




Conrod Bolt Tension
35 ft/lb




Main Bearing Tension
67 ft/lb= bolts 57ft/lb = nuts



Crankshaft Pulley Tension
70 ft/lb




Flywheel Tension
150 ft/lb




Points Gap
.015"




Dwell Angle in degrees
60 + or - 5




Spark Plug Type / Gap
bp6es ngk w7dc bosch .025"



Ignition Timing ( max total mech #30)distributor is mecha
0-10 degrees BTDC (depends on fuel/comp ratio and distributor curve)
CO % (at idle)

3%





Oil Capacity
5 litres incl filter




Oil Filter (Industry Number)
screw on z418




Oil Type / Grade
20w/50 sg




Recommended Service Interval
3000 miles/ 5000 km




Crankshaft main journal dia
2.0005"-2.0010 (50.81-50.82mm)



Main bearings running clearance
.001"-.0027"




Connecting rods little end size
.8110"-.8115"




Gudgeon pin press fit
.008"-.0015" interference




Piston rings
width comps..059 x 2 oil .138" end gaps on comp .008"-.015"

Valves 12g940 casting no.
inlet head dia 1.301" exhaust 1.156



Cam timing using .021" tappet clearance





Valve springs free length





Oil pressure normal running
75 lb/in (5.27 kg/cm2




carburettor needle single hif 44 1-3/4 su
std bfy red spring




diff ratios
efi 3.2:1 carby 3.105:1




fuel capacity
7.5 gals (34litres)