Hi timetc,

I made a blogpost on the reference material I have on the 1927 Flyer exhaust.
You can read it here

Cheers,
Erik

Hi timetc,

You are lucky… Jons answer triggered me…I suddenly remembered that Gill had send me a copy of this drawings too a few years back.
I had a quick look and I found them!

So Jon, do not bother to find a place to copy yours as I will throw my copies under the scanner at work tomorrow.

Cheers,
Erik

I’ve just spotted this post. Yes, I made a ’27 system for my long frame Flyer about 4 years ago from a drawing provided by John Underhill. the drawings were in the form of a set of A4 photocopies (which I still have, although they’re a bit oily by now) patched together with sellotape to make the full size drawing. I’m no engineer but managed to cut & shut the various parts & got a local welder to assemble them. The tailpipes curve under the frame & turn outwards at the end and were bent by a company in Coventry & subsequently nickel plated. The end caps I turned in aluminium. The downpipes & pepperpot I painted with black exhaust paint which has largely disappeared now & it’s beginning to look scruffy. I had a lot of trouble getting the various joints to seal as the pepperpot distorted somewhat during welding. A point to note is that the drawing that John provided shows straight downpipes (which is what I made) but I have since seen contemporary pictures which I think show curved pipes. Perhaps someone else could comment on this. Also, because the tailpipes are quite short and end at the front of the rear rim the back of the bike gets into a bit of a mess, I’ve used Castrol R which doesn’t help. It is very loud and vintage sounding & I sometimes wish it was just a little quieter but I’m told by others that it sounds really nice when “on song”.

If I can help in any way please don’t hesitate to get in touch via PM

Roy.F

This topic caught my attention because of the reference, by Brian Marshall, to the “True Yowl” . The late Titch Allen, writing about the various Scott exhaust systems, also said that the sound from a shortstroke engine with a coffee-pot exhaust was the sweetest and most musical of all. Of all the iconic features of a Scott the yowl is surely the most treasured and inspiring. The Club magazine was not named “Overhung Crank” , “Honeycomb”, “Red Cylinderblock” , or “Torque Band”
was it?

“Too raucus” was another Marshall comment, but a loud exhaust can be an important safety factor on our overcrowded roads, waking up cardrivers to our presence. Plenty of modern bikes are quite loud anyway and they seem to get away with it. Some may disagree. Lofty Avis built an extra long, dismantleable, Burgess for his ’49er which he said allowed him to ride right into his gateway, after the pubs had closed, without waking the Missus. His SuperSilencer, looking well used, is sitting in my workshop and if anyone really wants to try it out they would be welcome to, for the cost of postage only.

An interesting consideration is the possible effect of the coffee-pot expansion chamber and “stinger” on the engine performance. Can it be tuned to enhance power or torque in a similar way to the modern twostrokes I wonder. Tim Sharp thought so after fitting one which he believed was too voluminous.

The cult of originality would probably deter most owners of later, longstroke bikes from playing around with a coffee-pot but if I ever get around to resurrecting my 1958 Special I think I would want to have a go.