Go Back to Marques and Men PageTrenberth

Trenberth 2.jpg (96063 bytes)The car was designed and constructed as a one-off special, during 1951, in South Australia by Murray Trenberth, using a Vincent Black Lightning V twin engine specifically imported from the Vincent factory for the car. This well-known vehicle in Australian racing circles had considerable success from its first outing in January 1952 where it took fastest time of the day at the Collingrove Hillclimb in South Australia.

Period successes (1952 - 1960) included: 1st South Australian Hillclimb Championship; 2nd Australian Hillclimb Championship; Outright Lap record holder, Port Wakefield Circuit in South Australia; 5th Australian Grand Prix in 1955; 1st Reno Trophy Altona Circuit ,Victoria 1956; and over 150 race, sprint and hillclimb wins. It was the last air-cooled car to compete in the Australian Grand Prix (1962).

The Trenberth was raced by Murray until it was purchased by the late Don Willison, a well-known Australian Speedway Sidecar champion, in 1960 and raced by him until his death in 1973. The car then passed through 3 other owners before being acquired by Kerry Horan in 1990 who competes regularly in hill climbs and races.

The car’s specifications were quite advanced for its day. It has a tubular ladder chassis with 3” diameter tubes weighing 35 lbs bare with a wheelbase of 86”, front track of 50” and a rear track of 49”. Only front bodywork was used, built in alloy and no rear bodywork was ever fitted.  The original paint used, according to Murray Trenberth, was household Spartan full gloss enamel, bought from the local hardware store. The car still retains its original burgundy body colour with all other components being finished in black.

Murray fabricated the front independent suspension with unequal length wishbones, the lower ones being constructed of square tubing and the upper ones fabricated from sheet metal.  Coil springs and fabricated uprights are used and the stub axles are connected to the wishbones by ball-joints. A tiny rack and pinion steering was made. The independent rear suspension is by swing axles, chain drive (no differential), tubular radius rods and is suspended on rubber bands. The rubber bands were originally cut from 6.00” x 16” inner tubes and today bands from truck tarpaulin fasteners are used.  All of the rear suspension and drive components were specially fabricated including tubular swinging axles and the rear hubs which use large diameter roller bearings. Tubular shock absorbers are fitted all round. There are twin leading shoe brakes with 10” x 1 ” alloy drums on all four corners giving a relatively large brake lining area. All of the brake components were specially made including cast alloy brake shoes, dural wheel cylinders and stainless steel pistons. The brake design, according to Murray, was based on photographs of the brakes of pre-war Mercedes Grand Prix cars.

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Nickel chrome brake drums were cast integral with specially designed alloy wheel centres.  The chromed steel wheel rims are copies of early 1950s Renault wheel rims and bolt to the wheel centres.  A new factory racing Vincent Black Lightning V twin (998cc) engine and gearbox was ordered from the Vincent factory through the Adelaide Vincent agent, Sven Kallins and fitted to the car from new. A modified clutch was used after the original Vincent clutch exploded. The motor was modified very early on to overcome the problems encountered with crowded rollers identified by the speedway Vincent sidecars. Local Adelaide replacements of the crankpins, bearings and main shaft proved successful for long running reliability. The engine, running on methanol, and using a 12:1 compression ratio, developed 80 bhp and in a car weighing only 500 lbs, gave a ratio of 320 bhp per ton and excellent performance.

A Vincent Comet single (498cc) modified to Grey Flash specifications with a Norton gearbox was also used for different events.

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