Hi Rocket Racer
Thanks for the interesting pics, looking particularly at the center head bolt tapped hole do I understand correctly that the thick flange barrel casting is beefed up at the top as well as the bottom? When the top fin is removed that there is enough material left for the head bolt, which would make this conversion much easier to not having to weld in a plug.
Mine has loads of midrange though I feel it does not rev out to what I maybe expect (though I am used to the Trident) but I do not have a rev counter at the moment so don't really know. Things that may be acting as a rev limiter 376 cam? more of a midrange cam? 27mm carbs on the Shooting star head may also be a bit restrictive for a 650?
Chris P
Chris,
I recall there was a little welding involved which I recall ties up with the how to article from 1959. My engineer (who also did my timing side bearing conversion and built my replica BB32R frame!) knocked it out fairly promptly and also fly cut my pistons to clear the flywheels.
I doubt the pair of 27's are restrictive and the 356 is an excellent cam and stronger up to 6k and still pull through comfortably to more. I suspect your airfilters are too restrictive, I had a similar issue on an atlas race sidecar (filters being useful for trying to keep the kitty litter out, aka the gravel traps) and a dyno session confirmed the airfilters were putting the brakes on for eveything over 5k.
No its not a triple, but it has plenty of midrange and the life of these engines above 6500 starts to be measured in minutes and above 7k in seconds. On a road engine you shouldnt be expecting to be pulling the revs you pull on the track on a wing and a prayer.
Something to be conscious of with short rods is to time the bike by degrees not by distance btdc . the rod length alters the dwell at tdc.
When I was running a 4 speed I could keep it between 4500 and 7000 in top on the straights, anymore had me really sweating she would stay together while I kept the throttle pinned and watching the final climb from 7 to 7500 was fairly intimidating on a long straight. Now with a six speed I can gear more conservatively and keep it to 6500 although she is rarely below 6.
My head came off a shooting star but had been previously radiused. These heads wont take the big valves necessarily either but they will still boogie