Ok Norman..........here's the spec's on my motor. I used the online Java based expansion chamber software to arrive at these calculations. Not sure about the exhaust gas temp value.
Images:
First is the exhaust gasket.
Second is the screen shot of the calculations with the chamber laid straight..
Third is the chamber folded to mount to the front wheel fork.
The 21 mm pipe that welds to the exhaust flange has a circumfrence of 66 mm. while the perimeter of the rectangular exhaust port is 60 mm. I'm figuring a piece of metal bar would be formed to a rectangle with the measurements of 22 X 12 mm for using to form the 21 mm pipe to a rectangular end for welding to the flange. If that first piece of 21 mm tube were cut and swedged open 27 mm long then the other portion would fit inside it by 25 mm. That allowance would increase the first tube to 264 mm from 212 mm.
That would also allow the chamber to be moved to it's best mounting position beside the front wheel. But that's making the best of a 1317 mm (or 52 inch) chamber on a front engine friction drive 22 cc motor.
........and before anyone says anything I'm sure the cones are going to be below the machine limitations of any slip roller known to man.
The front cone would be formed with a 66 mm X 317 mm X 129 mm cone blank and the aft cone would be formed with a 38 mm X 110 mm X 129 mm cone blank.
But that just about builds it on paper. Just not sure about that exhaust stack temp...as it could make the chamber even longer if that value is too low.
The tech specs for this motor states it developes 1 hp at 6500 rpm's.
The software lays out the last screen shot for about 14,000 rpm and is a better length 26 1/2 inch total length. (and best suited to a motor between 21.9 and 38.4 cm/3 ) I'm still questioning the feasabliity of the solutions this designing software offers. So I think I'll try some other ap's to see what they come up with.
I'm sure if I painted the Chamber a bright brass color some would think it's a musical instrument I'm packing along.
