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[Count Johnny]

Good Morning All



I'm about to build a 612 engine to which I will be attaching a very short (board tracker style) exhaust and am thinking on a means of positively locating it to the exhaust port.



Like my current pipe, it will be 2" in diameter - stepped down to slide into the exhaust port - so I merely need a means of positively holding it in place.



Right now, I'm thinking 2 stainless exhaust springs attached to a hole drilled in a cooling fin either side of the port, or (even better, perhaps) a couple of internally threaded aluminium posts that are welded to the fins to hold a slide over clamp in place, but I'd love to hear from anyone who has done this before - or is much cleverer that me (which is everyone!).

[Alan R]

Hello COUNT JOHNNY------ I can't remember offhand just where I've seen this idea ( BSA chaps, maybe ??) but it involves drilling a 1/2" dia. hole down through the cyl. head fins on either side of the exhaust port for about 1.5" depth..........A 1/2" dia steel bar approx. 1.5" long has a 1/4" diam. threaded hole at half its' depth going all the way through...........When this bar is placed into the drilled hole, a 1/4" threaded bar is screwed into the 1/4" threaded hole and Loctited into place.........The other end of this 1/4" dia. bar passes through a ring welded onto the exhaust pie, and then through a hole in a loose collar...A washer and Nyloc nut complete the assy.............When the Nyloc nut is tightened the loose collar pulls against the welded ring and the pipe is compressed into the Cyl. head port.........

[ChrisD]

Hi CountJ. The article you probably need is one of the excellent ones by Royce Creasey from the late 1970's. I just re-found them in google. They're actually in www DOT royal-enfield DOT net. Enjoy!
ChrisD

[Count Johnny]

Thank you both!



This is EXACTLY what I needed and the article by Creasy ably illustrates Alan R's suggestion.