Specifications from the official MG Midget Series “TF” Workshop Manual. The TF was available with the XPAG/TF engine (1250 cc., to Chassis No. 6500) and the XPEG/TF engine (1466 cc., from Chassis No. 6501).
Engine
| Type | XPAG/TF (to Chassis No. 6500) / XPEG/TF (from Chassis No. 6501) |
| Number of cylinders | Four |
| Capacity (XPAG/TF) | 1,250 cc. (76.1 cu. in.) |
| Capacity (XPEG/TF) | 1,466 cc. (89.4 cu. in.) |
| Bore (XPAG/TF) | 66.5 mm. (2.618 in.) |
| Bore (XPEG/TF) | 72 mm. (2.835 in.) |
| Stroke | 90 mm. (3.543 in.) |
| Compression ratio (XPAG/TF) | 8.1 : 1 |
| Compression ratio (XPEG/TF) | 8.3 : 1 |
| B.H.P. (XPAG/TF) | 57 at 5,500 r.p.m. |
| B.H.P. (XPEG/TF) | 63 at 5,000 r.p.m. |
| R.A.C. rating (XPAG/TF) | 10.97 h.p. |
| R.A.C. rating (XPEG/TF) | 12.86 h.p. |
| Cooling system | Thermo-siphon — pump and fan assisted |
| Firing order | 1, 3, 4, 2 |
| First oversize bore | +.010 in. (.50 mm.) |
| Second oversize bore (maximum) | +.040 in. (1.00 mm.) |
| Piston clearance at pressure face below oil ring | .0021 in. to .0029 in. (.056 mm. to .071 mm.) |
| Ring gap | .006 in. to .010 in. (.152 mm. to .254 mm.) |
| Number of compression rings | Two |
| Number of oil rings | One |
| Oil pressure relief valve operates | 50 to 70 lb./sq. in. (3.5 to 5.0 kg./cm²) |
| Oil pressure (normal) | 40 to 45 lb./sq. in. (2.8 to 3.2 kg./cm²) |
| Gudgeon pin type | Clamped |
| Gudgeon pin diameter | 18 mm. (.7087 in.) |
| Crankpin diameter (standard) | 1.772 in. (45 mm.) |
| Crankpin minimum regrind (XPAG only) | 1.722 in. (43.75 mm.) — No regrind permissible on XPEG |
| Connecting rod length between centres | 7.008 in. (178 mm.) |
| Connecting rod bearing type | Shimless, steel-backed, white-metal-lined |
| Connecting rod side clearance | .004 in. to .006 in. (.10 mm. to .15 mm.) |
| Connecting rod diametrical clearance | .0005 in. to .002 in. (.011 mm. to .056 mm.) |
| Number of crankshaft bearings | Three |
| Main bearing type | Shimless, steel-backed, white-metal-lined |
| Standard main journal diameter | 2.047 in. (52 mm.) |
| Main journal 1st regrind (XPAG only) | 2.027 in. (51.049 mm.) — No regrind permissible on XPEG |
| Main journal 2nd regrind minimum | 2.007 in. (50.98 mm.) |
| Main bearing diametrical clearance | .0008 in. to .003 in. (.020 mm. to .075 mm.) |
| Crankshaft end thrust taken on | Centre bearing |
| Number of camshaft bearings | Three |
| Camshaft bearing type | White metal (front), Zinc alloy (rear and centre) |
| Camshaft end float | .005 in. to .013 in. (.125 mm. to .325 mm.) |
| Camshaft drive type | Duplex chain, 3/8 in. pitch, 60 pitches, endless |
| Valve timing markings | White chain links and “T” marks on wheels |
Exhaust Valve
| Throat diameter | 1.126 in. (28.6 mm.) |
| Head diameter | 1.338 in. (34 mm.) |
| Stem diameter | .315 in. (8 mm.) |
Inlet Valve
| Throat diameter | 1.274 in. (32.6 mm.) |
| Head diameter | 1.417 in. (36 mm.) |
| Stem diameter | .315 in. (8 mm.) |
Valve Timing
| Valve seat angle | 30° |
| Tappet type | Hollow |
| Valve lift (inlet & exhaust) | .315 in. (8 mm.) |
| Inlet valve opens | 5° before T.D.C. |
| Inlet valve closes | 45° after B.D.C. |
| Exhaust valve opens | 45° before B.D.C. |
| Exhaust valve closes | 5° after T.D.C. |
| Inlet valve working clearance (hot) | .012 in. (.30 mm.) |
| Exhaust valve working clearance (hot) | .012 in. (.30 mm.) |
| Valve guides | Removable |
Fuel System
| Fuel tank reserve level | Warning light on panel |
| Fuel delivery | S.U. electric pump |
| Carburetters | S.U. semi-downdraught |
| Carburetter needles | Standard: GJ, Rich: HI, Weak: GI |
Clutch
| Type | Borg & Beck 8 in. (20.3 cm.) diameter, dry plate |
| Facing | Woven yarn type |
Gearbox
| Synchromesh | Second, third and top |
| Top gear ratio | 1.00 (overall 4.875) |
| Third gear ratio | 1.385 (overall 6.752) |
| Second gear ratio | 2.07 (overall 10.09) |
| Bottom gear ratio | 3.5 (overall 17.06) |
| Reverse gear ratio | 3.5 (overall 17.06) |
Front Suspension & Steering
| Camber (static) | 1° positive (tolerance ±1°) |
| Castor angle | 7° ± 0.5° with side-members parallel to road |
| Toe-in | Nil |
| King-pin inclination | 9° to 10.5° full bump |
| Track — disc wheels (front / rear) | 47.5 in. (1.203 m.) / 50 in. (1.27 m.) |
| Track — wire wheels (front / rear) | 48.625 in. (1.224 m.) / 50.875 in. (1.29 m.) |
| Turning circle | 31 ft. 3 in. (9.525 m.) |
| Wheelbase | 7 ft. 10 in. (2.388 m.) |
| Tyre size | 5.50-15 |
| Tyre pressures | 18 lb./sq. in. (1.27 kg./cm²) |
Rear Axle
| Type | Semi-floating |
| Drive type | Hypoid |
| Ratio | 8/39 = 4.875 : 1 (alternatives: 4.55 : 1 and 5.125 : 1) |
| Adjustment | By spacers and special fixtures |
Brakes
| Type | Lockheed hydraulic two leading shoe (front), 9 in. diameter |
| Lining type | Ferodo DM.7 |
| Lining size (front & rear) | 8.75 in. x 1.5 in. x .187 in. |
| Rivets per lining | Twelve |
Springs
Front
| Type | Coil |
| Free length | 9.59 in. ± 1/16 in. (24.36 cm.) |
| Mean coil diameter | 3.238 in. (8.24 cm.) |
| Number of effective coils | 7.5 |
| Diameter of wire (ground) | .498 in. (1.27 cm.) |
| Maximum deflection | 4.24 in. (10.78 cm.) |
Rear
| Type | Half-elliptic |
| Length | 42.5 in. (107.95 cm.) |
| Width | 1.5 in. (3.81 cm.) |
| Number of leaves | Seven |
| Thickness of leaves | 7/32 in. (5.56 mm.) |
| Camber (free) | 2.85 in. (7.24 cm.) |
| Working load | 397 lb. at nil camber |
Hydraulic Dampers
| Type | Girling or Armstrong |
Electrical
| Distributor rotation | Counter-clockwise |
| Automatic advance | 25° on crankshaft at 3,100 r.p.m. |
| Contact breaker gap | .014 in. to .016 in. (.36 mm. to .40 mm.) |
| Sparking plug | Champion NA.8 (14 mm.), 7/16 in. reach |
| Sparking plug gap | .020 in. to .022 in. (.50 mm. to .56 mm.) |
| Ignition timing | T.D.C. (full retard) |
| Charging system | C.V.C. |
| Battery | Lucas GTW9A2, 51-amp. at 10 hours, 12-volt, Positive earth return |
Capacities
| Sump | 10.5 pints (12.6 U.S. pints, 5.96 litres) |
| Gearbox | 1.25 pints (1.5 U.S. pints, .71 litre) |
| Rear axle | 2.25 pints (2.7 U.S. pints, 1.3 litres) |
| Cooling system | 10.5 pints (12.3 U.S. pints, 5.7 litres) |
| Brake fluid | 1 pint (1.2 U.S. pints, .57 litre) |
| Fuel tank | 12 gallons (14.4 U.S. gallons, 54 litres) |
General Dimensions
| Length | 147 in. (3.74 m.) |
| Width | 59.5 in. (1.518 m.) |
| Height | 52.5 in. (1.34 m.) |
| Ground clearance | 6 in. (15.24 cm.) |
| Turning circle | 31 ft. 3 in. (9.525 m.) |
| Weight (unladen) | 17 cwt. 1 qr. (1,932 lb., 878 kg.) |
| Weight (laden with two passengers) | 22 cwt. (2,464 lb., 1,120 kg.) |
Torque Spanner Data
| Cylinder head stud nuts (up to Engine No. XPAG/TF/31727) | 600 lb./in. (6.9 kg./m.) |
| Cylinder head stud nuts (from Engine No. XPEG/TF/31728) | 500 lb./in. (5.75 kg./m.) |
| Connecting rod big-end bolts (to next split pin hole) | 320 lb./in. (3.7 kg./m.) |
| Main bearing cap nuts (to next split pin hole) | 750 lb./in. (8.6 kg./m.) |
| Steering wheel attachment nut | 500 lb./in. (5.75 kg./m.) |