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Velocette KTT

Velocette's enormously successful KTT series had
been developed for 14 years when the MkVIII appeared at the Earls Court Show in
1938. Priced at £120, the model was another 'race replica' in the great
Velocette tradition and included a host of innovations seen on the works
machines that had won that year's Junior TT.
With lightweight alloy parts, sophisticated oiling and a pioneering suspension
design, it showed all the benefits of development by a consistent programme of
racing.
The most notable feature of the engine was its
massive cylinder head casting, with its squared-off light alloy fins virtually
filling the frame. Introduced on works racers in 1937 and sold to
the public as a limited run of Mk VII KTTs early in 1938. Similar finning
extended to the rocker box, which contained a labyrinth of oilways to lubricate
the bevel gears and cams.
The Mk VII had a fairly modest state of tune
(with an 8.75:1 compression ratio) and a rigid frame with few special fittings.
The Mk VIII was altogether a different proposition. It featured 'swinging-arm'
rear suspension and Dowty oleo pneumatic rear shock absorbers, in which the
springing was by air under pressure, with oil damping. It had lightweight
magnesium alloy brake hubs and a telescopic housing for the front fork spring,
while the engine had been beefed-up to an 11:1 compression ratio. The valves on
the works bikes were filled with sodium for better cooling.
Ridden by Stanley Woods, the Mk VIII won the 1939
Junior TT for the second year running, just after Velocette's great designer
Harold Willis had died of meningitis. The model did well in private hands too
lapping Brooklands circuit at lOOmph.
War then brought a close to racing as to so many other things and Velocette
built around 2200 versions of its pushrod models for military use.
When production resumed after the war, the Mk
VIII was good enough to take two 350cc world championships and win the Junior TT
three years running. Production continued until 1950, by which time the double
overhead-cam Manx Nortons were taking the honours in world class racing. But
with a top speed of I05mph, the production models enjoyed a long competitive
career with enthusiastic amateurs, who celebrated the brilliance of a design
that enjoyed almost a quarter of a century at the top.
Velocette MkVIII KTT (1949)
Years in production: 1938-50
Engine type: single-cylinder overhead-cam
four-stroke Bore and stroke: 74 x 81 mm Capacity: 348cc
Compression ratio: 10.9:1 ' ^
Top speed: 110 mph |