A JW4 chassis took
part in one race at Stockholm in September 1967, driven by Sigvard Johansson
it was unplaced. The JW4 was first built in 1965 by Johnny Walker for
F4 racing, originally they were fitted with a 250cc Villiers Starmaker
engine but the engine proved unreliable. The car was rebodied for 1966
and a number of the cars were sold to customers. In 1967 Walker approached
legendary aerodynamacist Frank Costin (creator of the F1 Vanwall bodywork)
to design a new car, work was slow due to financial constraints and although
the car was finished late in the year and tested successfully Walker decided
to retire from racing. The car raced by Johansson was the later Costin
design and was fitted with the three-cylinder, two-stroke 850cc Saab engine
that was fitted in the Saab 96 model introduced in 1960, this was the
most powerful of the Saab engines.
Thanks to Peter Johansson
for additional information.