poor quality repop silencers

Bill Thomas

Well Known and Active Forum User
VOC Member
You could take it back under warranty..............Just say it failed from porosity............:rolleyes:
Not so far from the truth!, I was talking to Peter at Armours a few years ago, And he showed me a silencer that had been sent back as faulty, You could see where the bloke had tried to bash out the baffles, But for good will, They replaced it !. Cheers Bill.
 

stu spalding

Well Known and Active Forum User
VOC Member
An easy way to baffle a S/S silencer is to take two bits of 1 5/8" dia perf tube, flatten the ends to 1 3/8" and weld them in with the flat bits at 90 degrees to each other and a 3" gap between them. This gives an almost "straight through" while keeping the noise down. Cheers, Stu.
 

tatty500

Well Known and Active Forum User
Non-VOC Member
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I doubt that the VOC spiral baffle silencer does replicate the original Carbjector silencer. I think that the spiral baffle should be the full diameter of the outer shell, as shown in the 1949 sectioned drawing. I fitted a VOC silencer as soon as they were available and took the bike to the local dyno. The engine had lost 4bhp compared with straight through absorption silencer. That evening I put the old silencer back on the bike and sectioned the new VOC one to see how it was made.
John,
Oh, how I remember my original spiral baffle back in the 1970's on the twin. The spiral, being made up of bits on the central tube, would have been nigh-on impossible to weld in many places to the outer casing. Bits of the spiral would break away and eventually cause severe power loss when they arrived at the tailpipe. Shutting the throttle would suck them back and power would be again restored (for a bit). Many bits became small enough to be ejected. Eventually the remains of the spiral sub-assembly started to float back and forth inside, but application of a ball-pein hammer to the shell stopped this for a while.

Similarly the Hillgate one on the tatty Comet which was unused when I commissioned it has chucked several bits out the back. This also suffered from the fact that the entry to the spiral was very small and tight whereas the original appears to have a more open, less tightly wound start turn.

That's the first time I've seen the insides of a new one and I suspect that the fitting of the spiral into the perforated inner casing has allowed the spiral to be welded at its outside diameter at many places to prolong life......without making a mess of the nice shiny outside. A Comet bark is loud after the silencer....can't imagine how percussive it is at the inlet end.

Tatty
 

timetraveller

Well Known and Active Forum User
VOC Member
As John Emmanuel has raised his head here above the parapet on this it might not be too impolite to point out that John not only did wonders for the front fork geometry. I have seen the silencer that John made for himself. It has a larger diameter than the original but not so much that it looks out of place or causes trouble by grounding. John made his own spiral and the by drilling small holes around the outside of the silencer body was able to tack weld each course of the spiral in three places to the outside. Nothing moves or rattles. The weld marks cannot be seen as, like the ones where the front and rear hemispheres are welded on they are polished out. There might be more to this than the above but it is up to John to decide whether to tell everyone what was involved. Certainly, a lot of work.
 

John Emanuel

Active Forum User
Non-VOC Member
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As John Emmanuel has raised his head here above the parapet on this it might not be too impolite to point out that John not only did wonders for the front fork geometry. I have seen the silencer that John made for himself. It has a larger diameter than the original but not so much that it looks out of place or causes trouble by grounding. John made his own spiral and the by drilling small holes around the outside of the silencer body was able to tack weld each course of the spiral in three places to the outside. Nothing moves or rattles. The weld marks cannot be seen as, like the ones where the front and rear hemispheres are welded on they are polished out. There might be more to this than the above but it is up to John to decide whether to tell everyone what was involved. Certainly, a lot of work.

Having found that the spares company spiral baffle silencer lost 4bhp and caused the engine to run very rich throughout the rev. range, I put the straight through absorption one back on the bike.

Sometime afterwards the bike failed the noise test at a Cadwell track day so I knew I had to do something.

Back in the early 1990’s Ron Kemp sent examples of various manufacturers of Vincent silencers for me to dyno test on my bike which then had a standard engine. The best was an extremely old, rusted through example, with a full diameter spiral baffle which we presumed must be an original Carbjector. It was as quiet as the hopelessly restrictive Campbell, didn’t affect the carburation and lost less than 2bhp compared with the straight through. At the time, I found a patent application by the Carbjector company from the early 1920’s which showed a spiral baffle the full diameter of the outer case, so I concluded that they really did make it that way.

In 2011 I made my take on the Carbjector silencer. It is a 3 ½”diameter, compared with the usual 3” or 3 ¼”and longer than usual to get as much volume as possible. There are three rows of holes at 60 degrees to weld the baffle to the outer case which is a length of 3 ½” by 16swg commercial tube. Armours sold me the end caps and the inlet and tail pipes came from the spares company silencer shown in the first photo. The spiral baffle I welded up from segments of just less than one turn which were made by a specialist firm, (it seems to be impossible to form a continuous spiral).

It passed the noise test at the next Cadwell track day at 98db and loses less than 1bhp compared with the straight through.
 

Texas John

Well Known and Active Forum User
Non-VOC Member
From Armour's: "I have a stainless steel vincent silencer for the model ‘B’ on 1 5/8” inlet as it is S/S it has a pinch bolt on the inlet so does not require any detachable silencer clip."
After a number of emails with Armour's sales department, I have ordered one in Stainless Steel. I have also convinced them that they would sell better if they were on the website so they can be found and ordered! They informed me that they plan to do so in the near future.
 

Bill Thomas

Well Known and Active Forum User
VOC Member
From Armour's: "I have a stainless steel vincent silencer for the model ‘B’ on 1 5/8” inlet as it is S/S it has a pinch bolt on the inlet so does not require any detachable silencer clip."
After a number of emails with Armour's sales department, I have ordered one in Stainless Steel. I have also convinced them that they would sell better if they were on the website so they can be found and ordered! They informed me that they plan to do so in the near future.
Hello John, It's a small shop, Been going for many years, Very Old World, You would have a job to find the place !!, I went up and down the road for ages when I moved this way 11 years ago.
I think we are lucky they are still open, Peter in the shop retired a few years ago and as I have said the main Man Passed this year, They have never been up on Computers, Just do what they know best, I have not been there for a year or so, But they must be finding things hard. Cheers Bill.
 

Chris Launders

Well Known and Active Forum User
VOC Member
I made a similar pair to John Emmanuel's for my SS100 replica as Brough also used carbjectors, a friend used a drawing program to draw up sections of helix to weld together and another friend got them lazer cut, all I had to was weld them end to end and then stretch them out to form the helix, weld a tube in the middle and then insert them into some 3" tube and weld in place before fitting the ends just as John has done, I had tried to get some made but was quoted £190 EACH unplated.
If anyone wants to have a go I've got some of the helix sections left you could copy, the Brough silencer is the same 3" diameter as my Vincent.
You could do them in steel and have them chromed or stainless.
Chris.
 

pkrich

Forum User
Non-VOC Member
Hi just out of interest does anyone know the make of the silencer in the picture, with the side cut out, as I have the same silencer with a loose baffle. I am just deciding whether to cut and re
weld or replace it.
Also how good is the finish on the Armours stainless steel
Silencer in comparison to the chrome silencer. I ask because
normally the stainless isn’t as bright as chrome.

Pete
 
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