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Vincent Silencer

VincenttwinPL1

Forum Website User
Non-VOC Member
Can anyone tell me if the Vincent spiral baffle silencer was made in house at Stevenage?
A drawing of the baffle and silencer can be seen on page 125 of "Know Thy Beast", does anyone have a fully dimensioned drawing of the original spiral baffle? How was the spiral attached to the can?

Paul
 

roy the mechanic

Well Known and Active Forum Website User
VOC Member
made by Burgess for vincent, gone bust many years ago. unless you are an originality nut forget it . they are quite restrictive on performance, have tried both, goes much better on a staigt through "silencer"
 

david bowen

Well Known and Active Forum Website User
Non-VOC Member
Can anyone tell me if the Vincent spiral baffle silencer was made in house at Stevenage?
A drawing of the baffle and silencer can be seen on page 125 of "Know Thy Beast", does anyone have a fully dimensioned drawing of the original spiral baffle? How was the spiral attached to the can?

Paul
Bob Culver at Letchworth would be the guy to ask
 

Len Matthews

Well Known and Active Forum Website User
VOC Member
I can't help with dimensions of the factory fitted silencers but it's true to say that some pattern replacements are too restrictive. This came to light several years ago at the Dutch Rally when Brian East was complaining about the lack of performance from his Twin. The late Allan Rennie was there with his Comet that was known to have a genuine factory silencer. Brian swapped his silencer for Allan's, went for a blast up the road and came back grinning like a Cheshire Cat so whatever was inside the factory one was obviously correct. As to the maker I seem to remember the brand name "Carbjector" has been mentioned in this context. Going back to more recent times, a lot of work went into the design and testing of the new silencers marketed by VOCSCo. to reach a compromise between noise reduction and lack of restriction.
 

Albervin

Well Known and Active Forum Website User
VOC Member
I think Len is closer to the mark with Carbjector. Burgess units have "Burgess" stamped on the barrel but the originals were plain. There is no doubt a "silencer" has a huge effect on performance but watch out out for carb settings when you fit a new one!
 

John Emanuel

Active Forum Website User
Non-VOC Member
Back in the early 1990s Ron Kemp let me have a number of sample silencers which he had obtained from various suppliers to be tested on my twin on the dyno. The straight through silencer gave 46bhp but was the noisiest. The others with varying degrees of restriction gave less, the worst giving 38bhp and upsetting the carburation causing a flat spot low down. It seems that, as it is not possible to have a large volume in the silencer, it is a trade off between noise and performance. However, Ron also sent a very old and rusty silencer which I am sure was an original Carbjector. This only reduced the performance slightly, was quiet and we all agreed was the best compromise.
I didn't cut it up to see how it was made ( it wasn't mine!...and at that time I had no thoughts of making one). but I did what I could to look inside by spraying white ink from either end. The baffle was a proper spiral the full 3 1/8th inches of the inside diameter of the centre part of the silencer and the pitch was such that the cross sectional area of the passage through the baffle was roughly equal to the cross sectional area of the exhaust pipe. I wish it was still around... it would be most interesting to cut it up to see how it was made.
 

VincenttwinPL1

Forum Website User
Non-VOC Member
Thank you all very much for your information! I have an "original" silencer, I think,....as it`s not marked and has been on the bike for a very long time. It`s not restrictive that I have noticed and I`m sure Stuart Metcalfe will back me up there as the bike went very well!! I say "went well", as due to a loose exhaust nut and therfore banging in the silencer on the over run the silencer was damaged and sounded like a tin of nails (my silly fault for not sorting it sooner). At the moment I have fitted a new old stock "cambells" silencer. The bracket is too thin but the main issue for me is the noise, it has a spiral baffle but its just not the same! With the original silencer fitted the bike sounded "lovely" and most people who listened to the bike tick over would say how very nice it sounded, my friend Bob Culver for one! Arrogant, yes, but I have heard lots of Vincents at recent rallys and not one sounded as sweet. I think I need to take the old silencer apart and find out it`s secret! Call me a "nut" if you like but I want the bike to sound like it was meant to. I`m not interested in fitting a straight through absorption type silencer, to me they make the bike sound rough and extra performance is not important. If I want to go fast I jump on my 140bhp 998s FE Ducati! and thats a bike that does sound great with absorption race cans! Thanks again for everybody`s input! This Forum is a great way to find suff out! Well done VOC! Paul
 

Len Matthews

Well Known and Active Forum Website User
VOC Member
In my previous post I didn't want to mention the brand that caused problems but since Paul has mentioned it yes, those are the ones that can slow you down! (same name as those people who make condensed soup.)
 

VincenttwinPL1

Forum Website User
Non-VOC Member
Thanks Len, my typo, I mean "Campbells" silencer. I have not noticed any reduction in performance with this silencer only that it makes slightly more noise. The Campbells is a slightly larger silencer and external dimensions are different from the original. I`m not sure if this company still make silencers for Vincents as the one I have is NOS and was sat in my fathers loft for 30 years.
 
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