You could. I think the crank cases would have to come apart and be drilled and tapped for the standoffs, and who knows what else. Too much work for my cranky old bones. Easier to clean up the dribble and refill the primary for me, but heck yeah it's doable. Some great examples out there already on similar bikes and the P11.
Yes, it has been done and there was a report in the Jampot magazine of the AJS/Matchless Owners Club. Basically you need to make a banded spacer for the outer cover, about 1/2" thick.
The 6 start pump, large oilways and high-pressure lubrication of the cylinder head was introduced in February 1966 across the line of NHT. This was one year before the P11 was launched, and your P11 certainly had this feature.
It is entirely possible that the head I have is an older Atlas head. I have no way of knowing, I only know that it came from a partially disassembled engine (top end removed) that was stamped "P11 12XXXX". I'll have to confirm with motorson, but I think the crank may actually have had a 3 start oil pump drive gear, but no oil pump was on it, IIRC. Mismatched parts? Seems possible--the engine had definitely been apart before.
You have actually. A proper P11 head would have been furnished using a Birco "25319" casting. Of course you can't verify rocker spindles unless you dismantle the head. If untouched, you can be confident the head has plain rocker spindles.
Thanks, Knut. I had completely forgotten about the footrest mounting.
A motorcross bike with disc brakes at both ends? Is there a weight advantage by this conversion?
Motorson has a garage and I don't, that's why he puts up pics from time to time. The rear disc is actually a little smaller than the one I was originally going to use, and in truth I would like it to be smaller yet, but it will do for now. It is the disc that would originally have been fitted to that wheel--in fact the swingarm, rear hub, and rear brakes all came from early 1970's Kawasaki KZ750B's, (the twin cylinder KZ750, not the four). The swingarm is about 3 inches longer than the P11 item. I laced the rear hub with Buchanan's spokes into a repro 18" Akront. I actually had to ask Buchanan's to make me a custom set of spokes, but they were very easy to deal with on this.
Front fender is one of those things I spent money on--it is aluminum and I had it made by 7 Metal West. He can make fenders out of aluminum, copper, brass, can't remember if can do steel. I believe his usual customers are chopper builders. Anyway, he can make fenders/mudguards in various widths and lengths and in any radius you want. I had one full length front one made and one short one for the rear. He can also make them in various thicknesses; for durability's sake, I went with a full 1/8th inch thick, (.125"), which I believe is the thickest he can do. At the end of the day, I doubt I spent any more than I would have done for a nice set of original ones.
Believe it or not, at this point the bike is already registered! When I had the title transferred over to me in TN, I automatically got registration as well. So as long as I get it ridable before March 2023, I should be totally legal to ride it, provided it has lights, horn, the usual street equipment. You can see that I have already fitted a mirror.What are your plans for a speedometer? Or is this P11 going to be dirt only?
It could be a unique Dual Sport bike. A real crowd pleaser with open high pipes.
The longer swing arm will help when you go over the Widowmaker in Utah.
