171mph from a Velocette

[JOOLZ]

I found this article today...http://velobanjogent.blogspot.co.uk/2013/02/171600mph-from-single-cylinder.html   Who said thumpers are slow

[Moto63]

Thanks for the post joolz, really enjoyed the read and the photo,s. would,nt mind popping a supercharger on the old xbr, be a first?   Regards moto63

[JOOLZ]

Im already working on that, it will be the final stage of my modifications. When I have the spare money I will get an AMR500 roots supercharger.
Lots of problems Supercharging a single cylinder engine though, you need a huge volume for the plenum chamber I have worked out how to put a drive from the engine for it and the plenum volume and see no engineering difficulties.
I also investigated centrifugal superchargers and they may be an easier fit as they require a smaller plenum.
Extra heat output would need to be dissipated, so you would need to have a big fin head as well as an oil cooler to run a blown road bike reliably.
You would also need to replace the ignition system as you dont want timing advance as it comes on boost and you cant have a wasted spark system as that could cause an explosion in the plenum.
If you are serious about supercharging your XBR I can give you more info

[Propellor]

Wasted spark on a single cylinder?  Because it is fired at crankshaft speed?

Winder if you could rig something up off the camshaft?

Or maybe via an idler pulley off your blower belt?

[Moto63]

Thanks again joolz for the info, yes I am giving it very serious consideration and have talked about it with my big bro who is  far more capable than I at the engineering side of things, I,ve even considered selling my triumph speed triple to fund it. Desperate measures for desperate men and all that. I read with interest your posts on your xbr build and you certainly seem to know your onions, so might just be taking you up on your offer of more info in the near future. Best regards moto63