"I had a spare Jaguar V12 lying around, after I'd broken up an XJS for a trike project, and I'd always intended to do a V8 - but with so many already being done, I figured I'd go one better.
I haven't spent any money on it - virtually everything that I needed, I was able to source from my workshop, or out of my scrap bin. The only parts I've had to buy in especially are spark plugs, a flywheel (2.9, six-cylinder), exhaust gaskets, and one of the turbos.
I made it all up as I went along. I used an XS1100 middle gearbox, with a Land Rover first motion shaft, clutch and cover. The release bearing was originally a Discovery bearing and arm, but during a visit to my friend's garage I found in his bin a TD4 Freelander hydraulic release bearing, which is fantastic for the job. After dicking about for three days with the Discovery release mechanism, I found the one out of the Freelander did the job with only fifteen minute's work!
Its pretty terrifying to ride, at first. It only has one gear and a clutch, but that's all it really needs with 300+ horsepower and 400 ft/lbs of torque. I've got the hang of it now, though, and it's actually surprisingly stable - like a huge Goldwing. I think it must be something to do with the huge rotating masses acting as a gyroscope, as you can turn it on full lock, barely moving, and not even have to put your feet down."