Thursday, April 03, 2008

Vintage Velocette Venom Sprinters

I recently picked up 'Motorsprint' (in Dutch! Ramkema/Cornet - 1973?) which details the motorcycle sprinting action in Holland in the late 1960's/early 70's. It was an interesting period; old engines of all sorts (Velo, Vincent, Triumph, JAP, etc) could be picked up fairly cheaply and tuned within an inch of their life, supercharged, and installed into 'rail' chassis with fat slicks. These old engines would often compete with brand new Kawasaki H3-based sprinters, with an occasional Honda or Kawi 4-cyl thrown in as well; it was the twilight years of British motorcycle domination in all forms of motorsport, and some amazingly fast machines were (and still are) run down the track. Witness my earlier post on the Norton-JAP sprinter at Brighton - machines such as these still take FTD's at competitions.

I plucked these photos from the book as they are all based on Velocette's 500cc pushrod Venom, and show different approaches to the same goal - going much quicker than the Goodman's ever thought they could!

The top photo shows a very clever adaptation of what looks like a dohc Manx cambox to a Venom cylinder head. Not the first dohc Venom, and certainly not the last, but a difficult job to pull off cleanly. One has to empty the timing chest and run a bevel drive from the crankshaft, as per the KSS/KTT model. Unfortunately, the book doesn't have a shot of the far side of the motor. Note the seat and fuel tank.

Second pic shows a more standard Venom, with swept back pipe and mighty megaphone. The frame is constructed of square tubing, and the seat looks mighty uncomfortable. The bike belonged to Peter Harman; this photo was taken in 1967.

Last three photos show the supercharged bike of Rob Cornet, from 1972. It managed a 12.4 second run on the quarter mile in this configuration; belt-driven Shorrock blower, SU carb, BTH Competition magneto, standard Velo clutch. Note boost gauge next to the rev-counter on the forks. I'm fairly sure this bike exploded dramatically at Santa Pod dragstrip in July '72.

1 comment:

Anonymous said...

Hi Paul,

Rob Cornet is a good friend of mine, the same Thruxton is now back in service as a road bike.
He still has all the bits of piston that came out of the exhaust when it bang at the Pod...
John Nienhuis