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”
“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.