Canadian Flag Acadian Flag USA Flag Atlantic Green UK flag
Go to the HOME page -
1968 Dunstall Atlas
David Comeau updated April  2008
General Dunstall background

Project Background
This picture below, was taken at the British Motorcycle Meet in April of 1981. 13 years old already. It is the original blue gelcoat fiberglass. The little tail section cubby hole cover missing at this point. I will be trying to restore it to this cosmetic appearance/style as it likely left the factory. The bike is now in the process of restoration. A full series of measurements will be performed  to verify it's specifications.

photo courtsey of Calvin Vitale, owner of the bike at that time.

Now a year later, in spray can metallic green, this image was  taken at the 1982 INOA Bar Harbor Maine rally. It was said to be an extremely fast bike, and was noted for it's tire smoking burn outs.  The engine internals are like so many pieces of  polished jewelry.  Very impressive! Concentric Amal carbs and points/coil ignition. F&R 19" Boranni rims. Exhaust has balance pipes. The large diameter Rickman single disc brake was one of the types used by the Dunstall racing effort in 67-68 seasons. Probably much more of a real brake than the Dunstall dual disc show pieces. It's nickel plated frame is seen already in rusting blisters.
1968 Dunstall Atlas
Photo courtsey of Jeff Santere, NENO member & 1982 rally participant

 A look down the intake ports  these are  32mm ports but the valve pocket porting is not the same as later combats.
The springs looked like S&W type and were heavily shimmed. Stock keepers, the inlet valves were 63gm. VS 71gm. stock.
Exhaust was a PD part#,  running in bronze guides.
 left side rockers  Almost hard to believe the level of craftsmanship, I have seen some modern attempts to duplicat these, that are pale in comparison.
>Found to have .090" above deck GPM pistons, # 734  DUNSTALL. The rings were slightly worn and would have been OK, but I had new rings and put them in. this would make the compression close or above combat commando levels.
Dunstall Trivia-cam profiles
 Dunstall cam -PD04ZC >This cam profile is in my Dunstall atlas, it is shown advanced, exactically as installed in the engine.   This same profile was also in my  hot rodded  71 commando (Dunstall equipment).

 Dunstall cam-PDR2 Believed to have come out of a later 810 commando, roller bearings and pressure oil feed to lobes.

The lifters upon inspection looked reasonablely OK, except for the fact that the lightening process left a weak area. This area is between the hole drilled and the slot, where it is at it's thinnest. ALL 4 lifters were cracked at this point. The norton lifters are 73.3 gm. and the modified ones are 69.0 gm. It doesn't seem to be worth lightening the lifters if they can't take the strain. After all the cam is not that severe.!
 Dunstall modified lifters

primary, clutch and gearbox appeared to be stock norton

swing arm
>Now ready for  stripping of the nickel/chrome plating. After stripping,  the top front chain guard holder will need repairing due to the chain damage.
swing arm

Cyanide stripped TOTALLY  clean of all copper, nickle and chrome.
Then top front chain guard holder was repaired
Next, I had tig-welded up about 12 major rust pit areas on the right hand tube, and ground and filed back to flush.
Additional 2nd pass of about 8-10 additional welded areas, ground and filed back to flush.
The swing arm was then submitted to Bay State Chrome (now out of business or under a new name) for plating only.
The swing arm is very nice.

>Shown here is the bare rusty frame. The broken tabs for the oil tank and head steady need to be repaired.
rusty frame

The broken tabs were repaired.
The frame was submitted to partial sand blasting in a cabinet.
The extremeties could not be reached. what I call the rusting runners under run the original nickle/chrome plating. When sand blasted, the chrome nickle eventually breaks open exposing the rust. The rust has expanded up and away from the steel tube, since rust is larger than it's steel  base metal origin. Sandlasting breaks open the moleing and leaves a pit, edged by razor sharp flaps over the cleaned out rust pits. A fair ammount of the center part of the frame was cleaned. Cleaned pits being the result.
Some of the frame tubes were blasted and some were not. Much moleing was left. My  sand blasting attempt was not thorough, so an expensive but a completely effective cyanide strip was decided on, similar to the swing arm strippping.
Unfortunately the FRAME didn't get the stripping and cleaning of the swing arm.
The frame was found to NOT have been cyanide stripped as paid for, since there was still evidence of old residual chrome and the moleing that I was desparately trying to get rid of. $600 was wasted with this disreputable company.

>Below is the 19" rear Boranni rim showing the unconventional cross 1 pattern. Nortons usually used a cross 2 pattern.
dunstall/borrani/cross 2