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Rudge Whitworth 350 1930
1930 RUDGE WHITWORTH 350. In racing it is a very rare
occurrence for a brand-new design, straight off the drawing-board, to go
straight to the top; even rarer for it to dominate a T.T. Yet that is what
Rudges did with their 350 c.c. model in 1930.
There had been racing 350 c.c. Rudges—or Rudge Whitworths to give them their
correct name, as emblazoned on the tank—before this, but they had been a rather
disappointing machine, apparently incapable of doing so well as their bigger
brethren.
Then in 1930 came the new engine. Really it involved only a
radical change in the actual cylinder-head design, for the new motor was almost
identical in the bottom-half with the 500 c.c. one.
The old cylinder-head had employed four valves, the stems of each pair, inlet
and exhaust, being parallel and operated by one rocker with two "fingers", one
for each valve. This resulted in a poor combustion chamber shape, as the bore
was too small to accommodate all the valves. Consequently, the head was of
unnecessarily large diameter, leaving a lot of odd spaces.
All this was changed in the new head. Four valves were
retained, but these were at the four "corners" of a perfectly hemispherical
cylinder-head and stuck out radially—i.e., on a line that was a continuation of
a radius of the hemisphere. To operate these a set of six rockers, three inlet
and three exhaust, were carried on the head. They made a lot of clatter, but the
power output was amazing.
In the cycle parts of the design, Rudges showed considerable advance on their
contemporaries. Both wheels (they were q.d. and interchangeable) had 8-in.
diameter brakes with wide shoes. Transmission was via a four-speed gearbox in
which everything ran on needle roller bearings. A handlebar lever controlled the
steering damper; both brakes were coupled to the pedal and compensated, with
overriding hand control for the front.
The Rudge team consisted of Tyrell Smith, Ernie Nott and
Graham Walker, and they cake-walked the race, Tyrell taking the record average
speed up to 71-08 m.p.h.—the first time it had exceeded 70
Six famous racers. (Left to right) H. G. Tyrell Smith, Ernie Nott and Graham
Walker, with the three Rudges with which they swept the board in the 1930 Junior
T.T., finishing in that order. That was the last occasion on which a push-rod
type of engine was to win a Junior T.T.
SPECIFICATION
Engine: single-cylinder 350 c.c. o.h.v.; four "fully
radial" valves. Ignition: magneto.
Transmission: chain via four-speed gearbox.
Frame: diamond pattern, with single down-tube to
front engine plate and single-seat pillar tube to
rear engine plates. Forks: single compression spring girders, with friction
damping.
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