Dunstall Silencers?
- Thread starter Tornado
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concours
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This is the engineering conundrum with motor bikes.
A QUIET muffler that flows well, to make power, must be physically LARGE. Unsightly on a motorbike.
No big deal, when hidden beneath a car.
A small muffler, that looks proportionately correct/pleasing/traditional will either sacrifice sound or flow/performance.
Where that engineering point of compromise is, has been debated for decades.
This is more applicable the less number of pistons (for the same given displacement).
Let the romantic stories flow...
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Of all the different mufflers that I've run over the 48 years of Norton ownership I like the set of Conti's that I installed on a '73 850 back in 1977. Great look and sound. I had to make mounting adapters but I worked in a machine shop at the time so no problem. I also liked the Dunstalls except that they rusted out in 2 years. Still hard to beat the look of a nice pair of peashooters, though.
Craig
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The BMW K series are extremely fast and quiet ...what up with that? Besides the 4 cylds
Before the longer Dunstall mufflers with the "ray gun" exits, Dunstall sold a shorter muffler that I think was actually a Wassell muffler which had a larger inside diameter tube made of perforated metal with a center perforated disc which we knocked out. The Contis had a similar shape and length. Those Wassell-Dunstalls, in my opinion were the best. Loud but powerful. We had to use a bushing to step down to the stock head pipe outside diameter.
Deckard
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I have 2 sets, the earlier are probably what you're referring to. Shorter, but still the same honeycomb baffle at the rear. Welded in, no 3 studs mounting the baffle. About the same sound. I just got entertainment when I started up the 750 after about a years downtime for transmission rebuild. Quite a lot of rust came flying out of them when I started the first time. I guess they were internally cleansed after that. All the Dunstall's that I've had need the bushings to mount to stock exhaust pipes. Seemed that the left side needed a welding tack to keep the 2 bushings from separating. Big bore pipes could probably do without, but they don't flow as well as stock for most motors.
Yes, now that you mention it, the latest version were longer. Three versions then, not just two. The version that I am referring to did not have that honeycomb/raygun ornamentation/baffle; they had a plain ol hole/tube, 1 1/2 or larger in inside diameter. Glass pack around a perforated tube/screen
Deckard
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And yet, there were 2 versions of the longer one's. Later one's had a center hole in the honeycomb baffle to put a disc on to mute. Kind of defeated the benefit of the exhaust upgrade. I almost scored a set on ebay, but lazy seller just put pipes with Dunstall's on in a flimsy cardboard box after I asked them to remove them and wrap carefully as they were rare. Of course the box was beat up and so were the Dunstall's
I know I am an old fogey and I don't want to rain on your parade, but I was racing when the Dunstall stuff came onto the market. Dunstall was the first person to supply after-market bits for Norton twins. What came out as standard on Mk2A 850 Commandos, was probably better than anything Dunstall made.
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