To the question " If you had a Commando with no engine, how much would you pay for an engine" I'm sure everyone has a different figure they would be willing to put up.
The cost isn't too bad if willing to purchase used parts from ebay, then rebuild as necessary.
I built a complete 920 light roadbike that way and it wasn't crazy expensive. It was a lot of fun hunting for bargains and gathering all of the parts over a two year period. I found a perfect MK3 crank for $140! Ken gave me a great deal on an alloy cylinder, that also helped a lot.
The end result is a very nice light road bike with a lot of extra grunt in the middle. I would say that it does compare favorably with a modern Triumph for braking, handling and performance if comparing the 920 Norton to an 865 ot 900 Triumph. For starters, the Norton finished up about 200 lbs lighter than an 865 Triumph!
That is quite an advantage for the Norton.
I wouldnt build that type of engine for racing as it becomes a time bomb for that application.
I recall that Doug McRae's horrific crash was caused by a stock crank letting go in a hotrodded engine that was being raced.
Fortunately , as others have pointed out, there are uprated new parts available for that type of use. They are expensive but worth it for the safety factor alone, never mind that the stock cases and crank just won't last very long when racing. ( unless one races very slowly
Glen
