norton dunstall 810

I have a friend that has three dunstall 810 cylinders he said he would get rid of, if anyone is interested Pm me a phone # and I will give it to him so he can call you.

comnoz said:

Both engines hit the torque peak almost identical. Above the torque peak the big pipe 880 went downhill. At 6500 RPM the 850 with small pipes and mufflers with a center tube made a good 15 horse more than the big pipe 880 with open mufflers. The difference was dramatic. Jim

Click to expand...

So change the exhaust...or...tear down the motor and get a wilder cam in there...and a few more head mods....to work with the trick looking pipes....but don't go shopping on it....

Actually what would be interesting is if shorter big bore pipes would work with it, on the dyno, but I guess that it would need some form of high level exhaust to feed into those peashooters to actually be able to ride it....

Or, try it with 1 1/2 pipes, first and then centre tubed mufflers....as a workable compromise?

Back in the Day, I bought a new 1971 Commando. After finding that it would not catch the Kowa Tripples I started to Dunstallize it.
First I bought the 810 Kit & PD3 cam, & ported the head as per Paul D's instructions.
It was faster but not a rocket ship.
I bought one of the Dunstall 2 into 1 into 2 exhaust systems & the decibel silencers and the bike got faster.
A couple of years later I was traded a Paul Dunstall cylinder head with the re angled and larger valves.
This turned the bike into an 11.7 second bike. I never had any problems with the 810 kit, or lay shaft bearing. I did re do the mains to the superblends a some time . I drove it into the mid 1980's when I had to sell it to make a morgage payment.