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I am restoring a '59 Manx 500 and I bought a new pipe etc from Unity Equipe. With the pipe fitted at the exhaust port, the pipe touches the rear edge of the timing cover but the bottom of the pipe has not tucked under the narrow bottom section of the gearbox-outer-cover. In fact with a straight-edge against the top of the gearbox-outer-cover the inside edge of the bottom of the exhaust pipe is still some mm away from the edge.The result is that the megaphone sticks out some way. My question to all you Featherbed S/S Manx gurus is - Is there a set dimension for the distance between the narrow part of the gearbox outer-cover and the inside edge of the exhaust pipe ? The pipe may well be at fault. Thanks and regards, Howard
I would not want it touchi…
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I would not want it touching anything, with all the vibration something would get beat up. I have a 59' Manx 500 too I am trying to put together but I am not far enough along to final fit the exhaust pipe yet.
As old as these bikes are, and with who-knows-what they have been through, crashes and parts swapped, I would bet that every single Manx you tried your pipe on would have it fit differently.
Someone fitted my Manx with the later short cylinder and two-ring piston in the past, so that right there is going to lower the pipe a bit compared to a three-ring cylinder. Also I made new engine plates as the old ones were beat and not original anyway, and that again could change things.
I plan on having a machine that can actually be raced, so I am not too worried about cosmetics and I will cut and re-weld, and/or bend my pipe to suit the finished bike. Plus I want to try to keep my bike close to how it was when it was used to win a road-racing championship one year in the sixties, Gardner carb and all, so I do not have to worry about all the original details thank goodness.....
I would bet that the only way to get a exhaust pipe to fit an old Manx perfectly would be to have a shop custom make it for you then have it chromed last.
Someone has also fitted the latest cams to my bike, which means I am thinking of using the intake manifold from the 61' on bikes which was lengthened to suit the cams for better mid-range, which means that if I fit the standard Manx tank, I may have to have it with the carb cutout larger as the later bikes did too..... so it is like a custom bike build, I can not just buy parts and have them bolt on and be done with it for sure. I may even go with a high-pipe, which I have heard makes them run much better, and I have a six-speed shaftleitner cluster which might also go into it instead of the four speed. Lastly the bike was used in the past with a Seeley four-shoe, which I may keep on it too, I guess I will not know until it is done.
My engine is all old parts, it has an NOS stock big roller big-end and hairpin springs, non of the new replica parts on it, so I would like it to run in a way so I can keep the revs below 7000 during a race and use the torque peak rather than the horsepower peak.
Sorry about not having a proper answer for your question though....good luck.