Geoff was the throttle man, but that thing sounds like no XS I've ever heard. In all seriousness it would be a real treat to record that engine noise in much the same manner as the H16 F1 car from 1949. if you get a chance drop over to YouTube and have a listen to the clip of pink floyds drummers car at a track in England and you will get the idea. The exhaust note from that chair is by far one of the best I have ever heard.
Gday Bahnsy, I do totally agree about the sound of that XS engine. I asked EML about it and he said the firing order had been changed and the 2 cylinders fire like a big single. It sounded awesome.
Stan.
Thanks for the nice comments lads,
Heres a bit of info on the engine:
The firing order has been changed, however it doesn't fire as a single.
Instead of firing every 360'degrees, (parallel twin 4 stroke), it fires 270'-450'-270'-450'degrees and so on.
The right hand crankpin is 90'degrees ahead of the left one.
This is the same firing offset as a 90degree V-twin (ducati, good noise), but instead of the cylinders being 90degrees apart, the crank is.
The main objective of this was to reduce vibration, which it has done significantly.
It has turned it into a really smooth reving engine with loads of torque, and the traction is amazing due to the un-even firing pulse going through the back wheel.
Matt.