Amateur Manx 40M preparation

Rear mount.

Oil tanks in fairings, not sure why this would have been done. There's no shortage of space in its original position and the big foot tank holds 6 pints (specials can hold a gallon!). I guess "if" the bike had a lozenge tank, the type fitted 61/62, which is smaller then a header tank could be made and fitted into the fairing for longer races. Got to remember with open valves and just 2 gaskets in the manx engine was an oily affair. I have seen small side oil tanks in the fairing for primary and rear chain lube?! Early bikes would used engine oil taken off via a boss on the lower front of the oil tank. However Norton abandoned this for 1956 and put the oil in the left hand frame loop.

Rest on a sunny saturday. Instead of solving real problems remaining, put a catch tank in place.

Looks like a plumbers nightmare.

27 degrees Celsius is too hot for me. Not more done, only a fairly decent looking kill switch and a diaper. Don't know the proper english word for it, maybe bellypan. Took me hours to figure out how to fasten it. Remembered my old professor in machine elements talking a lot about value engineering. In short keep it simple. So drilled 6 holes in it and 6 cable ties. Maybe 4 should have been enough.

Exhaust. Not the simplest task. As I'm planning to use the bike, the pipe welded together with the megaphone it came with went to the "saved original parts bin". A new pipe, exhaust pipe rose and some kind of muffler was needed. Pipe and nut from a well known british supplier. Does they fit? Keeping old british motorcycle tradition, answer is no. Turning a bronze ring solved nut problem. Hours spent milling and grinding made a decent tool for tightening the nut. As a final touch, drilled a number of lockwire holes in the rose. Nortons exhaust nuts are known for coming loose. Next problem was fitting the pipe. It fitted well, except the small detail that it interfered with the foot peg. So it had to be bent down at least 1/4". Everybody that has tried to bend a pipe knows that it's almost impossible to get a nice bend without buckling the pipe. Buying a pro pipe bender for just one small task was out of question. Best alternative is to sand fill the pipe and plug the ends. Then heat it red warm and carefully bend it. Done that a couple of times and it works great. In this case it was only a slight adjustment so I tried on a couple of pipes I had, without sand filling. After some trial and error found it possible to do. Biggest nozzle I had in the welding torch, keep distance to the pipe and not too much heat on the side prone to buckling. Worked OK, smooth bend. But the nice chrome finish gone. But this is a racer, not a show or museum piece. Next problem will be a silencer. Plan to make a quick and dirty one just to get the bike running. Have to get it run in. After that some dyno runs testing, different kinds of silencers.

The problem with manx exhausts and makers of is this, the manx came as a long stroke 350 and 500, a short stroke 350 and 500 with 3 ring piston and finally the shortstroke 350 and 500 with two ring piston. Also gearbox case shape plays a part too, the AMC box is cutaway allow the pipe to tuck in more than the laydown box.

What this all means is that the exhausts are all different but the manufactures today will just make one type. So they are too low or the turn out curve from the head is too big and so forth. Make from scratch is the easiest way but the Norton pipes were mandrel bent not sand bent and YES Yoshimura plugged the pipe ends. There are guys in the UK that still do it, I can do parallel tube but not tapered megaphones, have tried but I haven't quite mastered that trick but will have too as some point, I have done adjustments but not full forming.

As for the silencer fouling the foot rest, take a look at the photo, this is how you get past the foot rest, there's a depression / dent made on the top off the silencer to help lift as much as possible. The photo is of a 350, the 500 hanger set up is different but still has the depression on top. Again all good info elsewhere on the site and note foot rest hanger also dictates the engine timing cover to header pipe clearance. In period the pipe usually touched the outer timing case and would wear a nice little hollow. Also note the clamp on the top of the silencer, not underneath, see bottom picture a just visible is the wear / witness mark made by the header pipe on the outer timing case.

More than 30C outside. Only 25 in the workshop. First I'll have it going without fairing, so the old number plates and the flyscreen went on. The flyscreen has two bent and cut John Tickle headlamp holders on the sides. No idea what top mount it shall have. The 1 3/8 GP2 the bike was fitted with is beyond repair. Threads in mixing chamber and cap is really bad. No fun if it comes loose and throttle valve goes up by itself. One reason I fitted a kill switch. As I have not got my greasy hands on a decent Amal GP yet, I'll go for a Gardner to start with. Only waiting for a correct needle arriving by post. Still not finished with the silencer. Now it is close to start it first time after 23 years of silence. Only one and a half year since I started to dismantle the bike.