Corse Performance

Sean Kynnersley, Head of Corse Performance, Workshop Manager for John Carr Motorcycles, and pit crew Chief for Matt Whitehead Racing tells how he came to build the only Ducati 649R in the world.

Having started my racing career some 10 years ago on an 888 kindly lent to me by another Desmo member Alan Walker, I found myself onboard many Aprilia RSVs, I even did the DOC track days at Cadwell and Mallory on Aprilias!

Some 3 years ago I accepted a ride on a rather trick 996 for the Stars at Darley Sound of Thunder meeting – I think I finished 3^rd – a race won by Richard Cooper on a BMW. This meeting proved to be a turning point in my career, I wanted to race a Ducati again but it had to be a 916 shape bike as the 999 just didn’t do it for me. The problem was trick 998-996s hold their value and I didn’t have that kind of money to invest in my club racing.

At the time mini Twins (or Formula 650 as we call it at Darley Moor) was becoming rather popular, but I couldn’t see myself on an SV650 or on a 748 with an SV650 engine, so I was going to have to make my own 650cc water-cooled 4 valve Ducati engine!! It seems funny now, but I spent many years working for Steve Wynn trying to make 888s bigger, now 20-odd years later, here I was trying to make a Ducati engine smaller.

I found a 748 rolling chassis easily, stripped it and sent everything away to be powder coated and painted. Whilst that was being done I picked up a couple of “blown-up” 748 motors from a well-known online auction site. I then bought an SV 650 piston and cylinder just to see how Suzuki did it, or if I could possibly use an SV piston, the latter was not an option and was quickly ruled out.

I then stumbled across a website called “Chris’s Bore/Stroke Indicator” (I think). On this site was a list of every bore and stroke of every belt driven Ducati made to date. The only thing I had to do was get as close to 650cc as I could, as the rules state 650cc four-stroke twin. What I ended up with was a big bore 748 with a mega-short stroke – PERFECT! Although there were people who said it wouldn’t work. So I got a shopping list together, 749 piston in bored out 748 cylinders and a 400ss crankshaft, this proved to be rather hard to find. What I ended up with is 90mm bore and 51mm stroke – 649cc!!