Trojan's One-off: The Mastra

Car Encyclopaedias don’t have much between Maserati and Matchless. The Mastra was no more than a footnote in the Beaulieu tomes under “Trojan”. Yet An Entirely New Six-cylinder Model with the Engine Mounted at the Back, at Olympia in 1935 is worth noting. After plodding for years with an ingenious square-four 2-stroke engine and whirring Brooke Bond Tea vans, Trojan of Purley Way Croydon went out to challenge Rover.

Trojan wanted to move up-market. Expensive cars made more profit. How the catchy title was coined remains obscure however. Nowadays costly consultants would come up with something but this was 82 years ago. If Studebaker could call a car Dictator, it seemed, nothing would stop Trojan going for something Masterful.

Trojan’s RE had been a disappointment in 1929. RE only meant Rear-Engined, its final drive was by chain and under founder Leslie Hayward Hounsfield (1877-1957), it wanted to do better. In engineering since before the First World War it didn’t start making cars until the 1920s. It shared a factory at Ham Common, Kingston-upon-Thames with Leyland so the first cars were shown jointly at Olympia in 1922. Trojans had 2-stroke engines, usually horizontal under the floor, a 2-speed epicyclic transmission, chain drive, and solid rubber tyres at £2 each against £5 for pneumatics. Blow-up tyres were fitted reluctantly. “Our agents are sometimes asked: Can I have my Trojan on pneumatics? We don’t think them necessary. But if you regard the luxury of pneumatics worth the risk of a puncture, why not?”

Solid tyres went twice as far as pneumatics without wearing out. Trojan’s long cantilever Wondersprings gave an astonishingly supple ride for cars firmly in the bargain basement. Their performance was between moderate and really slow, engines were the essence of simplicity and economy with only seven moving parts, four pistons, two V shaped connecting rods and a crankshaft.

The four cylinders were side by side in a square cast iron block. Each pair shared a common combustion chamber and the pistons were connected to a single crankpin. This meant that the slim arms of the V bent slightly every revolution, so although the pistons were together at top and bottom dead centres, they got out of kilter during their stroke. One piston opened the exhaust port just before the other opened the inlet, which helped scavenging. Small and quiet under the floorboards, the little unit ran at only 1500rpm on petroil, and the contortions of the con-rods never seemed to do much harm.

Hardly any changes were ever made, beyond replacing plain big-end bearings with rollers, and reducing the capacity from 1523cc to 1488cc making it officially a light car paying less tax. Ham Common had a twin-track assembly line, engine castings coming from Leyland’s foundry in Lancashire for finishing and boring.

Flat-out Trojans could do between 30 and 35mph yet showed extraordinary agility on hills. At little more than walking pace they could ascend inclines of one in eight in high gear, or one in three in low. In 1925 the price was reduced to £125, the same as a Model T Ford, and against the Austin Seven at £149. The simple chassis was easily adaptable for commercials, Brooke Bond bought 800 in 1927-1928, running them for three years before selling them back to the makers for little more than scrap value. Trojan then cheerfully sold them on often unrestored. The GPO and the RAF were big customers.

Trojan cars were popular as taxis, some went as far afield as Japan, and by the end of the decade 80 to 100 a week were being made. Nearly 11,000 of 16,800 Trojans made were cars, until in 1928 Leyland decided it wanted its factory back, leaving Trojan to fend for itself. It was forced to contemplate smaller numbers so took two initiatives. One was a six-wheeled cross-country vehicle, drawing on experience in trials such as the Exeter or Land’s End. Intended for the military it drove through both rear axles. On the lowest 48:1 gear the six-wheeler climbed a wet grass and chalk incline of one in two but to no avail. It could only do 30mph, too slow for the military, and only half a dozen were built.

The other proposal was to develop the RE, which began life with neither front wheel brakes nor electric starter (the regular Trojan had a ratcheted lever on the floor that spun the engine into life), but had a smart Riley-style two-door fabric saloon body. Cycle-type wings, low build, and with the engine now upright in what looked like a luggage trunk at the rear, it went on sale in 1929 for £179. It scored well on appearance against Standard, Triumph, and Singer but suffered a fundamental shortcoming.

Its evaporative cooling system, with header tanks and cooling matrix in the lid of the rear trunk and radial vanes on the flywheel to blow air through, was problematical. Production REs tried a conventional-looking rounded radiator at the front. Pipes ran underneath warming occupants’ feet but not cooling the engine. From 1931 to 1934, only some 250 were sold and Trojan went back to what it was best at - vans.

Leslie Hounsfield, aged 56, left in despair. He had invented a folding sprung-frame camp bed as a sideline and set up on his own, making it until the 1950s.

Trojan’s other big idea was the Mastra. In 1935 it was priced at £395 for a 4-door saloon, £380 for a convertible with two cylinders added to the square four by cutting engines in half and welding them in place. This made a sort of oblong six, and unlike the RE where it was upright, it was once again laid on its side, at the rear of the chassis. Rubber-mounted above the axle centre-line, inlet ports uppermost and exhausts underneath, it had a single-plate clutch and 3-speed synchromesh gearbox. The chain drive was enclosed in a transverse casing, connecting through a forward-facing shaft to a worm drive on the offset back axle.

The structure looked reassuring with channel-section side members, boxed in the middle, and a tubular sub-frame for the engine and gearbox. Suspension was by cantilever springs, with extra torque members on the tubular front axle, and semi-elliptics at the back. Brakes were Girling mechanical. Lessons from overheating REs were not forgotten and an engine-driven pump speeded the flow of coolant to and from the radiator at the prow. A by-pass valve was fitted to warm the interior. A front fuel tank helped counterbalance the weight of the engine at the back, at any rate when it was full, and was high-mounted to provide a gravity feed to the Trojan-made variable jet carburettor.

Bodywork this time looked more Wolseley than Riley, made by the newly revived Ranalah Coachworks, at Merton in South-West London. The saloon was a well-proportioned fastback, with a lump accommodating the final chain gearcase, Jackall hydraulic jacking, petrol warning light and self-cancelling indicators.

Trojan was cagey about power output of the 63.5mm x 117.5mm 2232.7cc engine. The 4-cylinder had not provided much more than 11bhp (8.2kw) for the 1315lb (596.48kg) Trojan in 1923 but even if the 6-cylinder was twice as powerful twelve years later, the Mastra was by no means swift. Such power as it did develop was dissipated in the tortuous transmission system and top speed was not much more than the RE’s 35mph. Wheelbase was 114in (289.56cm); track 57in (144.78cm); length 192in (487.68cm); and width 69in (175.26cm).

The Mastra was a determined effort, and although Trojan did not conceal its connection with it, the press was happy to regard it as an entirely new make of car. The Motor thought: “Students of design will find the Mastra exhibit a most interesting one.” It considered the 6-cylinder two-stroke mounted at the rear: “…a form of construction which many people believe will become common practice before long.” Symptomatic of Trojan’s aspirations, in publicity drawings a chauffeur drove the convertible.

It seems unlikely that either of the cars shown at Olympia, “in attractive metallic blue” was a runner. Perhaps the saloon never was, although the convertible underwent some kind of proving trial in Devon. At £10 more than the new SS Jaguar neither stood a chance. Three plywood bodies were once discovered rotting at the back of the works, along with engines. All were consigned to scrap in the 1950s.