COCK-UP CORNER
Alan Cathcart’s article about Ian Boyd and his Vincent collection in the June issue made a fascinating read – but during his dash through Vincent HRD’S history, Alan isn’t right to note that Python engines were the cause of the firm’s disastrous 1934 TT entry. Python, as Alan says, was the marketing name of Rudge power units, supplied in the early 1930s by the Coventry firm to Vincent and a welter of other small motorcycle outfits including AJW, Cotton and OK Supreme. But by 1934, Rudge’s financial worries meant that Python engines – which weren’t built to race specifications – were no longer available.
Vincent’s 1934 TT hopes relied on engines from J A
Prestwich (JAP). It was their high camshaft 500cc JOR racing engine which let the side down. I recall that broken valve rockers was the main problem, with all three riders – Arthur Tyler, Jack Williams and Jack Carr – retiring. Phil Irving, Vincent’s designer, was so cross that straight away he started work designing an in-house engine – also with a high camshaft – which went on sale in 1935 as the Comet and the Meteor (a Manx Grand Prix example is in Ian’s collection). Some say the new Vincent engine’s camshaft layout was influenced by Irving’s time at Velocette in 1930-31, when their successful ohv singles (the MOV, MAC and MSS) were in gestation. What is certain is that Irving wasn’t impressed with the layout of JAP’S race power units, which were returned summarily to the Tottenham factory after the TT. Dennis Frost, Thames Ditton
Thanks to Dennis for pointing that out. In my eagerness to progress to our lobster lunch, I must have misunderstood Ian Boyd’s history lesson! Further research discloses that 1934 was Vincent’s debut year in the Isle of Man TT, when they used a new JAP motor which Teddy Prestwich had assured Phil Vincent would be a sure winner. Perhaps it was the false expectations raised by this which prompted the two Phils to return said engines to JAP, and roil their own. Alan Cathcart
As an owner of one myself, I really enjoyed your recent article on the Ducati 750GT. One glaring error stood out, however. You state that the front brake was shared with the Mini Cooper. Absolutely not so! All 997 and 998cc Coopers had 7in discs; the Cooper S always had 7.5in. Even the reborn Rover Cooper of the ’90s only had 8.4in discs – a larger size made possible by the use of 12in wheels. The Ducati 750GT had a 278mm disc (almost 11in diameter), considerably larger than any classic Mini. Also, the Ducati caliper was always a twin piston type, not a single piston type as stated. Keep up the (mostly) great work!