New restoration project

Thanks, Gentlemen.

I can see that this one is going to be fun. Whilst it is my first Norton, it isn't my first restoration. I have three AMC machine and two Meriden Triumphs under my belt. 

Having had a chance to look at what I've got, the rolling chassis is, of course, the main "component" and that looks to be sound. I have a "matching numbers" crankcase but no internals. There is also a lot of stuff that comes from different machine. I have a complete engine (number "650SS 2042"), two complete AMC gearboxes, one with a number "N10485", one with no obvious number. I also have two totally different primary drives. A pressed steel chain case (inner and outer) and a cast aluminium inner and outer. Two clutches, an AMC 3 spring, single row chain and a diaphragm spring clutch with a triplex primary chain. Plus a load of other stuff I've yet to sort out!

Let the fun begin....

John

Learned bretheren,

I crave your indulgence and help... As mentioned in the first post, I have a frame and a set of bare crankcase halves with matching numbers "18 SS/105642/P". I also acquired at the same time, a seemingly complete engine. The plan was to rebuild an engine using the original, matching numbers crankcase and the internals from the donor engine. However, I'm not sure exactly what the complete engine is. It has two sets of numbers stamped into the crankcase. At the rear of the engine, just below the barrel on the drive side, it's stamped "650SS  2042".  At the front of the engine, just below the barrel on the drive side, it's stamped "104760  18". Is that usual? If so, which is the engine number?

Another thing... Looking at the exploded view / parts list for the engine on the Andover Norton website, the 650cc twin only seems to have a single row primary chain. The engine I have has a triplex engine sprocket fitted. I  believe that the Commando has a triplex primary drive but was the 650SS ever fitted with one?

Thanks in advance for any help and insights into this engine offered

John

Err... wow. That was quick. Thank you. Amongst the bits in the boxes I have inner and outer tin chain case halves and a complete AMC 3 spring clutch. I also have a set of somewhat butchered cast alloy chain case halves and a complete diaphragm clutch (I don't know how that works. Never seen one before!!)

I will endeavour to build this as close to standard as possible, but it will be a bike that's ridden, not trailered around shows, so I reserve the right to make make modifications for the sake of safety and reliability. 

John

Gentlemen and Ladies,

I have a question or two regarding AMC gearboxes. I have two that came with all the other stuff. As mentioned earlier, one has a number on it, prefixed with the letter "N". If I understand things correctly, this would indicate that the gearbox was manufactured before 1963 as from '63 onwards, the prefix became "NA"....  so it's possible as this is the original gearbox for the bike (possible built in early '63). So far so good. I've completely dismantled this box and it will be rebuilt with new bearings, oil seals, springs etc. 

The second gearbox is un-numbered but it does have an identifier. There is a tiny "breather jet" screwed into the inner cover, adjacent to the cable entry. Now, again... if I've got thins correct, this was only added from 1975, when the gearboxes were fitted to the MK3 Commando. That this is a Commando gearbox is further reinforced by the fact that the top mounting boss is about 1/8" narrower than the other gearbox.

First question... Am I right in my assumptions, regarding these boxes?

Second question... Can I rebuild the internals of the later gearbox (including inner and outer covers) into the older case with the number stamped onto it?

Forgive me if I'm being an idiot...

John