Thank you all (So far) for the replys. I guess I need to get my crank notes out again. I spent some time going thru my cranks to supply a spare crank for the other Golden flash project and spent many hours trying to ID cranks. I read many interesting posts about the various years and the transitional cranks, and some mystery cranks and a few setup for alternators.
I got the idea that there was some issues and some years differences in the drive and timing sides on a few..
Going to the cabin for a few days but next week will dive back into crankshafts and engine parts,
I am still sorting old shop inventory and parts and long term project(s) as I also have some other A10s.
Interesting point on the size of the dia of the journals vs widths of journals. The issue is what rods. I have some used late model rods, dont know until more sorting what I have for early rods if any. I also did not know you could get H beam rods for the early small journal cranks.
On a few A65s I built, I was told by Capt Dirt and some other racers that the hot tip was to modify the A65 rods by using Norton steel caps, resizing the rods and new bolts. This seems to be an accepted practice and seems to help rod life. Dont know if that is viable on A10 rods.
But I have some opinions on service life of an alloy rod. If affordable, I would prefer a NEW H beam rod.
I also, in my experience have found a lot of alloy engine cases out of tolerance either from shifting-age-distortion, or poor manufacturing. But on most motors we do a full engine blue printing. If I can find the pictures I have a series of photos from my old friend Sir Edward. A tool & die maker originally from the UK. Eddy was a perfectionist and genius and I learned much from him. (A few other engine and tuning gurus as well) So, any build like this will be fully blueprinted and tolerances fully optimized.
Secondly, I have a really awesome dynamic balancing guy. Ernie does Airplane props and certain types of industrial equipment as his day job but loves to do MC engines on the side.
been using him for 20 years and very happy with him. Its rare I will rebuild an engine with out fully balancing the parts. We experimented a few years back before my health issues with some A65 motors and different balancing figures and crank weights. Capt Dirt told me the key with the A65s was to take the lightest Triumph unit crank and match that weight with the BSA.
We did, and that motor revved like a dirt bike 2 stroke. I would have to get out my build notes,, but the BSA unit cranks are a LOT heavier than the Triumph unit cranks. I have a pile of flywheels that are NOS from BSA from a dealer. Still in the wrappers. I can post part numbers and weights but BSA offered a number of flywheels for the Unit twins. I will look at if they can fit (Probably not) a preunit crank, but there is some options.
But on this bike,, I dont think I want a motor that revs like a 2 stroke dirt bike. With a long rod motor like these motors have, Torque is where its at. I doubt Ill do much interstate/freeway riding. Mostly country roads and comfortable RPMS at 70 mph is my goal but strong pull from off idle to 70-80 mph is where I see this going.
Thanks as well for the suggestion on the engine parts weights. I will have to look into that.
On the Nortons, I am a big fan of the lightweight cam followers on the twins. Ironically many use BSA lifters.
See:
http://www.jsmotorsport.com/products.aspSir Eddy made his own versions for the Norton LSR race bike,, And I have some development parts here that Kenny Dreer was playing with. He was using modified VW lifters. I can post a pix of that as well. Simple but effective designs.
I have some alloy heads as well, and some performance cams, but I think I have some useable stock 356/357 cams. Need to see what I have for pistons,. But I know I have some NOS pistons, as well as some others.
I will update and post some parts pictures next week.