JAP bottom end with 2 Manx SOHC top ends, google COOPER NORJAP beautiful !!
Spotted this today
- Thread starter Puddle jumper
- Start date
There is a Vincent in Australia with two Neal Street dohc 4-valve heads intended for Jawa speedway bikes. Chain drive to each head driven by a sprocket where the Vincent cam lobes used to be.
A chap called Gregory did very well in hill-climb racing a decade or two ago with Neal Street heads on his own V-twin bottom end.
A chap called Gregory did very well in hill-climb racing a decade or two ago with Neal Street heads on his own V-twin bottom end.
I Was There !! I have been trying to remember his name, ---------- Gregory, He used to come to our Curborough Twisty Sprints, I thought the cams were belt ? It was Super, Bit like a Britton, It went like Stink ! and the sound, Anybody got any photos. I was so involved with the racing for years I didn't think to take photos.
Neil Street spent loads of money and time developimg his 4 valver for speedway, just as it was "coming good" the powers that be banned it! B#'stards.
Someone passed me on the m1 one day several years ago with a trailer with two gregory's on it, a single and a twin if I remember correctly, very neat.
What happened to them?
What happened to them?
First it was the flat head exhaust with a single overhead intake, then came the over head two valve head then came the single over head cam two valve then came the two valve double overhead cam, the three valve, four valve, five valve, desmo ,rotary valve, and a few that have slipped my mind at the moment,
the point is I have always enjoyed the engineering and the beauty of some but in reality , why the exercise when a blower in most cases would do the job with less hassle and expense. Where is my helmet and flack jacket?
the point is I have always enjoyed the engineering and the beauty of some but in reality , why the exercise when a blower in most cases would do the job with less hassle and expense. Where is my helmet and flack jacket?
First it was the flat head exhaust with a single overhead intake, then came the over head two valve head then came the single over head cam two valve then came the two valve double overhead cam, the three valve, four valve, five valve, desmo ,rotary valve, and a few that have slipped my mind at the moment,
the point is I have always enjoyed the engineering and the beauty of some but in reality , why the exercise when a blower in most cases would do the job with less hassle and expense. Where is my helmet and flack jacket?
Good question especially as supercharging seems relatively common on many cars with Mercedes having a whole range of "Kompressor" cars and many diesel cars are turbocharged as standard.
Maybe fitting a supercharger on road going bikes is problematic due to lack of space. Exhaust turbocharged bikes have been produced, e.g. the Honda CX 500 and CX650 were offered in turbocharged form. An exhaust driven turbo doesn't have the problem of arranging a mechanical transmission to the supercharger but you still have to fit in the pipework, etc.
Superchargers are much more compact these days, a friend is fitting one to a triumph and it is hardly any larger than the carbs it is replacing, it came from a modern car. Other than supplying a drive the main problem is probably insurance, I can imagine thier reaction to" Vincent Black Shadow oh and i've fitted a supercharger".
Chris.
Chris.
I looked into exhaust turbo chargers years ago when I had a friend who worked for one of the world's largest turbo manufacturers. Things may have moved on but at that time his opinion was that the turbo would not like only two unequally spaced pulses from a relatively slow revving twin. Superchargers are a different thing and it would be intersting to see the specs on one of the new really small ones. The other thing to remember is turbo lag.