No-one will deny that the MG Car Company of Abingdon made a huge contribution to British prestige in motor racing; the greatest credit to Cecil Kimber and MG’S racing staff. If I favoured other cars slightly more than MGs it was because they were, from the wonderful Midgets onwards, built from some Morris components, and the Midget’s four cylinder engine had Wolseley origins. How foolish one’s prejudices.
Anyway, after a splendid record of racing and rally successes, MG produced the larger 18/80hp six cylinder MGs. The MU appeared late in 1928, with a modified Morris Light Six chassis, back axle and brakes, but the 69x100mm (2468cc) engine, which had a chain-driven overhead camshaft, was improved.
The prototype saloon was driven solo by Sir Francis Samuelson in the 1929 Monte. It came third in the Mont des Mules timed hillclimb, and three 18/80s gained awards in the MCC High Speed Trial.
That same year, the MkII 18/80 arrived, with a four-speed gearbox and a stiffer chassis, etc. With sports body this Speed Six was capable of nearly 80mph and 60mph in second gear, a match for a 3-litre Bentley. Its 0-30mph time of 3.8sec was only 0.8sec slower than a supercharged TT Stutz.
The MkIII 18/80 was something else! Long-distance sportscar races were popular at Le Mans, Spa, in Ireland and at Brooklands, etc, and Kimber decided to build an MG which could compete in these and other competitions without its owner needing to make any changes. Its engine had a special four-bearing crankshaft which was balanced statically and dynamically, all moving parts were also balanced, and the conrods machined all over. A water pump instead of an impeller was used, the cylinder barrels ribbed to combat distortion. A special crossflow cylinder head was fitted, the latter with machined ports, and there were two downdraught SU carburettors. An overlap camshaft, triple valve springs and raised compression ratio also upped power. Dry-sump lubrication had the oil tank between the front dumb-irons. A heavy-duty dynamo was driven with a strong spindle used with the chain drive for the ohc camshaft.
Twin oil pumps scavenged the sump and fed lubricant to the main bearings. The oil tank had a filler and the starting handle passed right through it. Flexible external pipes took oil to cast-in galleries within the engine. Oil pressure was 60 to 90lb/sq in. Ignition was by a twin distributor supplying two plugs per cylinder, from twin coils.
A new chassis was stiffened with channel-section and tubular crossmembers, and the cork-lined singleplate clutch was designed to facilitate racing changes. Before the rear axle a low-set 28gal fuel tank was placed. The front axle was damped by double-action Hartford shock absorbers and the rear with two pairs of right-angled double-action Hartfords. The brakes had large finned drums, and the cam spindles were cadmium-plated and on roller bearings. A hand wheel for brake-pedal adjustment was on the offside of the chassis, convenient for a pitstop. The external fly-off handbrake lever, with its press-button ratchet-release as on the MkII 18/80 Speed Model, was retained. Separate Tecalamit fuel pumps fed through their own pipes, with a two-way tap, so if one system leaked the other could be substituted, and the well-braced triple headlamps — one of them very large — featured separate wiring.
The four-seater body complied with AIACR racing regulations but although this exciting MG was intended for competition usage, there was central chassis lubrication, a fold-flat windscreen, and a race-regulation folding hood. A horizontal three-branch exhaust manifold and pipe ran along the nearside, into a big Brooklands fish tail, compensated for expansion.
This remarkable car was to be supplied already run-in, its brakes bedded in, all nuts split-pinned and wired and steering parts filed and polished to detect any flaws. A first batch of 25 was announced, the price £895 compared to £525 and £630 for the MkI and MkII Speed models. The MkIII engine gave 83bhp at 4300rpm and it was hoped to guarantee 100mph.
The new car’s first competition outing was the 1930 JCC Double Twelve race at Brooklands. Drivers were Leslie Callingham and H D Parker. Alas, the car lasted for only two hours. The cause was given as a carburettor problem, but the press reported a broken piston. However, the true reason seems to have been failure of the main bearings, suggesting lubrication failure.
Callingham and Reid Railton later got 96bhp from the engine but production was stopped at just 25, as against 500 for the MU and 236 for the MkII.
How miserable that such an ambitious plan came to naught.