Engine specification and data	848 cc Mini Mk I and Mk II (types 8AM, 8AH, 8MB and 85H)	Mini Cooper 997 cc Type 9F	Mini Cooper 998 cc (Type 9FA)	Cooper S 970 cc (Type 9FC), 1071 cc (Type 10F), 1275 cc (Type 12FA and 12H)
Engine (general)		The engine specification is identical to the type 8AM specification except for the differences detailed below	The engine specification is identical to the type 9F specification except for the differences detailed below	The engine specifications are identical to the type 9FA specification except for the differences listed below
Type	4 cylinder, in-line, ohv	9F	9FA
Bore	2.478 in (62.94 mm)	2.458 in (62.43 mm)	2.543 in (64.588 mm)	2.780 in (70.6 mm)
Stroke	2.687 in (68.26 mm)	3.20 in (81.28 mm)	3.000 in (76.2 mm)
				970 cc 2.4375 in (61.91 mm)
				1071 cc 2.687 in (68.26 mm)
				1275 cc 3.200 in (81.33 mm)
Cubic capacity	848 cc (51.7 cu in)	997 cc (60.87 cu in)	998 cc (60.96 cu in)	970 cc (59.1 cu in); 1071 cc (63.35 cu in); 1275 cc (77.9 cu in)
Compression ratio	8.3 : 1 (8.9 : 1 for 8AH engine)	High 9 : 1	9 : 1	970 cc 10 : 1; 1071 cc 9 : 1; 1275 cc 9.75 : 1
		Low 8.3 : 1	7.8 : 1	Normal compression pressure at 500 rpm 190 to 200 lbf/in2 (13.36 to 14.07 kgf/cm2)
Firing order	1 - 3 - 4 - 2 (No 1 cylinder next to radiator)
Camshaft and camshaft bearings
Camshaft bearing clearance:
Front	0.0004 to 0.002 in (0.012 to 0.051 mm)
Centre and rear	0.00125 to 0.00275 in (0.032 to 0.07 mm)
Inside bearing diameter reamed when fitted:
Front bearing	1.667 to 1.6675 in (42.342 to 42.355 mm)	1.667 to 1.6675 in (42.342 to 42.355 mm)
Centre bearing		1.6245 to 1.6255 in (41.261 to 41.287 mm)
Rear bearing		1.3748 to 1.3755 in (34.914 to 34.937 mm)		1.374 to 1.375 in (34.9 mm)
Rear bearing length				0.7656 +- .010 in (19.45 +- .25 mm)
Endfloat	0.003 to 0.007 in (0.076 to 0.178 mm)			0.001 to 0.002 in (0.025 to 0.057 mm)
Journal diameters:
Front	1.6655 to 1.666 in (42.304 to 42.316 mm)
Centre	1.62275 to 1.62325 in (41.218 to 41.231 mm)
Rear	1.3725 to 1.3735 in (34.862 to 34.887 mm)			1.372 to 1.373 in (34.8 mm)
Connecting rods and big-end bearings
Length between centres	5.75 in (14.605 cm)
Side clearance	0.008 to 0.012 in (0.203 to 0.305 mm)
Bearing internal diameter clearance	0.001 to 0.0025 in (0.025 to 0.063 mm)
Small end bore diameter				0.8110 to 0.8115 in (20.60 to 20.61 mm)
Crankshaft and main bearings
Main journal diameter	1.7505 to 1.7510 in (44.46 to 44.47 mm)			2.0005 to 2.0010 in (50.81 to 50.82 mm)
Minimum main journal regrind diameter	1.7105 in (43.45 mm)			1.9805 to 1.9810 in (50.30 to 50.31 mm)
Bearing length		1.0625 in (26.99 mm)
Running clearance		0.001 to 0.0027 in (0.025 to 0.069 mm)		0.001 to 0.0027 in (0.025 to 0.068 mm)
Crankpin journal diameter	1.6254 to 1.6259 in (41.28 to 41.30 mm)
Minimum crankpin regrind diameter	1.5854 in (40.27 mm)
Main bearings:
Length				1.000 in (25.4 mm)
Endfloat	0.002 to 0.003 in (0.051 to 0.076 mm)
Undersizes available	-0.010 in (-0.254 mm), -0,020 in (-0.508 mm), -0.030 in (-0.762 mm), -0.040 in (-1.02 mm)
Cylinder block
Bore oversizes available	+0.010 in (+0.254 mm), +0.020 in (+0.508 mm), +0.030 in (+0.762 mm), +0.040 in (+1.02 mm)		+0.010 in (+0.254 mm), +0.020 in (+0.508 mm)
Gudgeon pins
Type	Semi-floating, held by clamp bolt		Fully floating	Interference fit
Fit to piston (hand push fit)	-0.0001 to 0.00035 in (0,0025 to 0.009 mm)		0.0001 in (0.0025 mm) to 0.00035 in (0.0089 mm)	Hand push fit
Fit in connecting rod (hand push fit)	-0.0001 to 0.0006 in (0.0025 to 0.015 mm)		0.0002 in (0.005 mm) max	0.0008 to 0.0015 in (0.020 to 0.038 mm) interference
Diameter (outer)	0.6244 to 0.6246 in (1 5.86 to 15.865 mm)		0.6244 in (15.86 mm) to 0.6247 in (15.867 mm)	0.8123 to 0.8125 in (20.63 to 20.64 mm)
Lubrication system
Oil filter type	Full-flow
Capacity oil filter	1 pint (1.2 US pints/0.57 litres)
Transmission casing/sump capacity (inc filter)	8.5 pints (10.2 US pints/4.83 litres)
Oil pump relief pressure	60 lb/in2 (4.22 kgf/cm2)
Oil pressure:
Normal	30 to 60 lbf/in2 (2.11 to 4.22 kgf/cm2)
Idling	15 to 25 lbf/in2 (1.05 to 1.75 kgf/cm2)
Relief valve opens		70 lbf/in2 (4.92 kg/cm2)
Relief valve spring:
Free length	2.859 in (72.63 mm)	2.609 in (66.28 mm)
Fitted length	2.156 in (54.77 mm)
Oil pump shaft and rotor endfloat	0.005 in (0.127 mm)
Oil pump rotor lobe clearance	0.006 in (0.152 mm)
Oil pump rotor-to-body clearance	0.010 in (0.254 mm)
Oil pressure (normal)		70 lbf/in2 (4.92 kg/cm2)		60 lbf/in2 (4.22 kgf/cm2) at 70 degC oil temperature
Pistons
Clearance of piston:
Top of skirt	0.0026 to 0.0032 in (0.066 to 0.081 mm)			0.025 to 0.0283 in (0.63 to 0.72 mm)
Bottom of skirt	0.0006 to 0.0012 in (0.015 to 0.030 mm)	0.0016 to 0.0022 in (0.041 to 0.056 mm)	0.0005 to 0.0011 in (0.013 to 0.028 mm)	0.0019 to 0.0025 in (0.048 to 0.063 mm)
Piston oversizes available	+0.010 in (+0.254 mm), +0.020 in (+0.508 mm), +0.030 in (+0.762 mm), +0.040 in (+1.02 mm)
Piston rings
Top compression ring	Plain	Plain, chrome faced
2nd and 3rd compression ring	Tapered
Fitted gap	0.007 to 0.012 in (0.178 to 0.30 mm)			(all rings) 0.008 to 0.013 in (0.20 to 0.33 mm)
Groove clearance	0.0015 to 0.0035 in (0.038 to 0.089 mm)			(all rings) 0.0015 to 0.0035 in (0.04 to 0.09 mm)
Oil control ring	Slotted scraper
Fitted gap	0.007 to 0.012 in (0.178 to 0.30 mm)
Clearance in groove	0.0015 to 0.0035 in (0.038 to 0.089 mm)
Width (all rings)			0.0620 to 0.0625 in (1.574 to 1.588 mm)
Thickness (all rings)			0.106 to 0.112 in (2.692 to 2.835 mm)
Compression rings:
Width				0.0459 to 0.0469 in (1.16 to 1.19 mm)
Thickness				0.116 to 0.122 in (29.4 to 30.9 mm)
Oil control ring.
Width				0.1553 to 0.1563 in (3.94 to 3.96 mm)
Thickness				0.116 to 0.122 in (29.4 to 30.9 mm)
Tappets (cam followers)
Length	1.505 in (38.23 mm)
Diameter	0.8120 in (20.62 mm)
Valves
Head diameter:
Inlet	1.093 to 1.098 in (27.76 to 27.89 mm)	1.156 in (29.4 mm)	1.219 in (30.86 mm)	1.401 to 1.406 in (35.58 to 35.71 mm)
Exhaust	1.000 to 1.005 in (25.4 to 25.53 mm)	1.000 in (25.4 mm)	1.000 in (25.4 mm)	1.214 to 1.219 in (30.83 to 30.96 mm)
Valve lift	0.285 in (7.24 mm)	0.312 in (7.92 mm)		0.318 in (8.08 mm)
Throat diameter:
Inlet		1.0312 in (26.2 mm)	1.172 in (29.77 mm)
Exhaust		0.908 in (23.06 mm)	0.908 in (23.06 mm)
Seat angle (inlet and exhaust)	45 deg
Valve clearance	0.012 in (0.305 mm)
Valve rocker clearance for competition work only				0.015 in (0.38 mm)
Stem diameter:
Inlet	0.2793 to 0.2798 in (7.094 to 7.107 mm)
Exhaust	0.2788 to 0.2793 in (7.081 to 7.094 mm)
Valve stem to guide clearance:
Inlet	0.0015 to 0.0025 in (0.038 to 0.063 mm)
Exhaust	0.002 to 0.003 in (0.051 to 0.076 mm)
Valve rocker bush bore (reamed)	0.5630 to 0.5635 in (14.30 to 14.31 mm)
Valve guides
Length (inlet and exhaust)	1.687 in (42.86 mm)
Diameter (inlet and exhaust):
Outside	0.4695 to 0.470 in (11.92 to 11.94 mm)
Inside	0.2813 to 0.2818 in (7.145 to 7.177 mm)
Fitted height above head	0.594 in (15.1 mm)
Valve timing
Inlet valve:
Opens	5 deg BTDC	16 deg BTDC	5 deg BTDC
Closes	45 deg ABDC	56 deg ABDC	45 deg ABDC
Exhaust valve:
Opens	40 deg BBDC	51 deg BBDC	51 deg BBDC
Closes	10 deg ATDC	21 deg ATDC	21 deg ATDC
Valve springs
Type	Single		Double	Double
Free length (inlet and exhaust):		1.750 in (44.45 mm)
Early models	1.672 in (42.47 mm)
Later models	1.75 in (44.45 mm)
Inner spring			1.672 in (42.47 mm)	1.705 in (43.31 mm)
Outer spring			1.75 in (44.45 mm)	1.740 in (44.19 mm)

Engine specification & data	Mini 1000 Mk II 998 cc (Type 99H)
The Type 99H engine is fitted to the Mini Mk II and Clubman and is the	same as the Type 9FA engine except for the following:
Engine (general)
Compression ratio	8.3 : 1
Inlet valve throat diameter	0.969 in (24.61 mm)
Valve lift	0.28 in (7.14 mm)
Piston oversizes available	+0.010 in (0.254 mm), +0.020 in (0.508 mm)
Engine specification & data	998 cc automatic models (Types 9AG and 99G)
Specification as per the standard 99H engine	but compression ratio is 8.9 : 1

VALVE CLEARANCES

Inlet and exhaust valves (cold) 0.012 in (0.305 mm)

LUBRICATION SYSTEM
Sump capacity (engine/trans. unit inc. filler)
with manual gearbox, refill 8 pints (4.83 litres)
with auto. trans., refill 9 pints (5 litres)
total               13 pints (7.38 litres)
System pressure     2
running             60 lb/sq in (4.22 kg/cm   2 )
idling              15 lb/sq in (1.05 kg/cm   2 )
Relief valve opening pressure 60 lb/sq in (4.22 kg/cm )
Oil pump:
Type                Hobourne - Eaton rotor type or Concentric
Inner to outer rotor clearance 0.006 in (0.152 mm) max.
Outer rotor to housing clearance 0.010 in (0.254 mm) max.
Rotor end-float     0.005 in (0.127 mm) max.

The following information gives only the points of difference
from the 848 cc engine and should be used in conjunction with
the preceding specifications.

GENERAL DATA 1098 cc ENGINE
Capacity 1098 cc (67 cu in)
Bore 2.543 in (64.58 mm)
Stroke 3.296 in (83.72 mm)
Compression ratio 8.5:1

PISTONS
Clearance of skirt in cylinder:
Top 0.0021 - 0.0033 in (0.05 - 0.08 mm)
Bottom 0.0005 - 0.0015 in (0.013 - 0.040 mm)
Width of ring grooves:
Top, second and third 0.0645 - 0.0655 in (1.638 - 1.663 mm)

PISTON RINGS
Compression rings:
Ring to groove clearance 0.002 - 0.004 in (0.051 - 0.102 mm)
Oil control
Fitted gap
Rails               0.012 - 0.028 in (0.305 - 0.711 mm)
Side springs        0.10 - 0.15 in (2.54 - 3.81 mm)

VALVES
Inlet valve and Exhaust valve
Stem to guide clearance 0.0015 - 0.0025 in (0.040 - 0.080 mm)

VALVE TIMING
Rocker timing clearance 0.021 in (0.533 mm)
Inlet valve
Opens               5' BTDC
Closes              45' ABDC
Exhaust valve
Opens               51' BBDC
Closes              21' ATDC