Commando cam

Well I just looked in my RGM parts book and they referr the Commando cam as STD camshaft no refreance to 1S cam and 2S camshaft as the sports cam as well with the 650SS camshafts fits all pre 70s (no refrence to 1S cam) and the Dommie camshaft to 2S profile (sports use) and in my old manual with the high performance section referr the sports cams as SS and race cam as SSS, I have had this book for 36 years or more now and is hard to get things out of my head as thats what I have been referring for all these years, so I got to get my old school thinking out of my brain and start to keep up with moden terms, even worst now I have retired early from work and for some reason my beer fridge keeps filling itself up :roll: , so all good, has been a good topic and settled some comfussions about how things are written.

Ashley

An easy way to remember it is - there is just one stock cam profile from the 650ss and Atlas onto the last Commando, Combats and Production racers being the only exceptions.
At least that is my simplistic take on it, could easily be wrong.

Glen

For what it's worth, when my 650SS wore out it's Dunstall racing cam, I went down to my local friendly Norton shop, Park Road Motorcycles confusingly in Shirley Road (!!) and spoke to none other than John Hudson. As a result I bought what he described as a Commando 2S cam, without the points drive, as in all superior motors the 650SS had a magneto. At the time I believe that the "2S" cam was made as a spare part for magneto motors, as it was somewhat superior to the "standard" 650SS cam, but that may be wishful thinking on my part. As the Dunstall cam had stuffed the cam followers, at the same time I got the appropriate followers, cannot remember if there were any differences between the old and the new.
The end result was that the motor was superb, with standard CR pistons, twin 30mm Concentrics and the standard exhaust the bike was a delight to ride. Nice flat torque production, revved cleanly right up to quite a lot. I can't remember what I revved it to, but it wouldn't have been more than 7,000 rpm. It would do about 115mph, and at a steady 70mph gave about 50mpg, English gallons obviously.
Hope this helps
cheers
wakeup

Yes the 2S cam profile will wake up the motor and the power will kick in just over 4,000 rpm and will run very freely and because its not a full race cam no need to modify the followers.

Ashley

in factory Trixie Combat and my other hot rod Combat with the big ole ports they felt like a 3rd piston kicks in @ 6800 so very hard not to let er rip on up into red zone with front lifting some. On plain ole Trixie [which I don't whip up on like I did Peel built for it] with 19T sprocket she pulls best after 90 mph indicated and keeps the strong pull going to at least 115 and will touch 120 if held on longer. That is about as fast as any sane sports elite will do in public Mt. roads so to hang with them means mostly WOT to redline drag races though gears to get up to speed and to pass cars in time. Factory Combat is just barely up to it if ya can be that hard hearted to wear it out faster too. Combats plenty spunky down low and ok on 87 octane if aware of it so to me Combat spect makes most all around off the shelf sense.

With hotter cams you generally gain at the high end and lose at the low end. This accentuates the feeling of power when the engine does finally come into the powerband, since there is a lull before the storm, more like a 2 stroke hit.

With the stock cam in an 850, the power spread is almost uniform, opening the throttle is like turning a rheostat knob on an electric engine. Lots of pull everywhere.

Glen