INSIDE KNOWLEDGE
In the article on Mike Hailwood’s 1961 TT performances in the July issue, it stated that basically his 500 engine was from 1960 and in stock specification. I can assure you this is not the case, as when this engine was being prepared, I was working for Bill Lacey shortly after completing my engineering apprenticeship. I went with Hailwood to the Norton works to collect a new 500 engine, which was completely stripped and modified, comprising a special drive-side crankcase half fitted with a steel sleeve for the drive-side bearing, and a lightened and polished Jaguar conrod with an oil feed to the small end, which ran on a machined-from-solid crank. The rod had a shell bearing, which required a much higher oil pressure, so a different oil pump was fitted.
‘A NEW 500 ENGINE WAS COMPLETELY STRIPPED AND MODIFIED’
I believe the valve gear was standard, apart from the cam followers which were aluminium bronze – the choice of this material was my idea, as it was a metal used extensively in my apprenticeship company. The bronze against the steel cam was kinder to both components and this set-up became known as the ‘Lacey valve gear’. I believe there were other mods – ie bore and stroke, and possibly a plated cylinder – but Bill was fairly secretive, so what the final spec was is probably unknown. I do know that it revved considerably higher than a standard Manx engine, and Bill said he was more than happy with the power. I am sure the Hailwood engine was his last word on the single-cylinder race engine, as shortly before this we had a Honda four-cylinder engine to examine and Bill said something to the effect of: ‘This is the end for single-cylinder race engines’. He did say that after the race he would bury the engine – and I’ve often wondered if he did.