Silencer loudness

Bought a new pair of silencers from a reputable dealer recently. They are too loud & quite frankly sound downright unpleasant.
Act more like an echo chamber than a silencer. I have had a few pairs of silencers over the years, these are easily the worst sounding. Are these the only make that can be obtained in Britain?

Flo said:

Bought a new pair of silencers from a reputable dealer recently. They are too loud & quite frankly sound downright unpleasant.
Act more like an echo chamber than a silencer. I have had a few pairs of silencers over the years, these are easily the worst sounding. Are these the only make that can be obtained in Britain?

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It would be nice to know what you got and from where.

I bought some from a well known dealer (situated in Staffordshire) & mine too are louder than I would like. Not offensively loud but definitely noisier than previous ones I had.

Ian

I don't know what it will do for the performance, and you shouldn't have to do this with new mufflers, but the peashooters on 850 Mk1 models, circa 1973, had little bits of removeable pipe in the ends. Fitted, they were quite quiet, removed were bordering on rorty. They were called 'mutes' in the parts lists, held in with a little screw. Jet sizes in the carbs needed to be altered to suit, according to the manual.

I have quietened some stainless mufflers, for something else, similarly by fitting such a bit of (stainless) pipe into the exits. If the performance was reduced, it was barely noticeable, but the noise certainly reduced, back to legal at least. That exit diameter obviously makes a serious difference.

Flo said:

Bought a new pair of silencers from a reputable dealer recently. They are too loud & quite frankly sound downright unpleasant.
Act more like an echo chamber than a silencer. I have had a few pairs of silencers over the years, these are easily the worst sounding. Are these the only make that can be obtained in Britain?

Click to expand...

And what make are they? Pretty hard to answer your last question without knowing that.

Ken

I got a set of Andover peashooters from Old Britts. They are the most quiet that I've had, out of 3-4 other brands. A funny thing though, I found that when I finally rectified a pretty rich jetting situation that the sound mellowed out considerably too.


http://www.oldbritts.com/16_061978.html

I came accross this a few years back and found at the time that the silencers with the visible weld at each end were quieter than the ones with no weld at the thin end, is this the case with yours? No idea who makes the various styles though ( no weld, one weld, two welds).

Nothing wrong with a good bark! When I had mine off I could a see a ping pong would shoot straight through

Niagara850 said:

Nothing wrong with a good bark! When I had mine off I could a see a ping pong would shoot straight through

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The original peashooters on a 73 850 were the same - at first glance there was nothing in them - the flutes in the walls obviously do something to the sound.
And those mutes really toned it down - and a ping pong would no longer fit with them there.

Interestingly, there is another thread here just now, about peashooters that are too restricted.
And drilling them out for some flow and performance and sound....

Agreed, the flutes must add to the rich tone

Now , everyone knows 80 mph is the quietest speed as you leave the sound behind .

Glass Pack mufflers were the in thing , around 1970 . Every cowboy had a resonator on the cortina tailpipe .
The resonator is actually supposed to go in front of the muffler , at a tuned length , to broaden the powerband
& maintain heat / exhaust kenetic energy / extractor effect .

So if you dont use over 1/2 throttle in town , on the Commando . its Quiet .



The fibreglass packing is supposed to dampen the shock wave so the muffler case doesnt reverberate , echo , flex .
Useually , the glass had collapsed / rotted out / dematerialised in a few years of entusiastic operation . Leaveing a
lightweight hollow caseing remaining along with the perforated tube .



good example of a well perforated tube , which will maintain red hot temp thus encourage exhaust gas inertia .

Pre 72 the Commando ' silencers ' were unrestriced generally . same with the Domi type . Though no doubt there
were various specifications for differant models . The most powerful requireing less impediment to flow .

Makeing a muffler - > http://www.theflyingbanana.com/mufflers.htm

Wassel was possibly one of the original equipment suppliers .



Norton S mufflers reverse cone silencers Wassell 061312
Ref: 061312 Norton reverse Wassell S cone silencers mufflers

The Norton ' mufflers ' had 20 or 22 G. shells . There Mega type had meaty 16 or 14 Guage .
The exhust wouldnt reverberate the case untill produceing real power , where the reasonance of high quality British Steel permeated the . . . Er . . . Countryside .

One can debate the term ' Muffler ' ( muffles ) & ' silencer ' ( silences ) & power Enhanceing Exhaust System / how do we get it past the regs . :lol:



" I am having trouble finding the original pipes and silencers for my S-type Commando Roadster. The pipes on it are less than perfect due to a slight brush with pavement a few years ago.
Geoff Rotheram

A beautiful and distinctive bike with absolutely no ground clearance problems. Demonstrating the S-type ground clearance. And a guest appearance by Pete Lovell.

S-type pipes (headers, silencers, heat shields and brackets) are being manufactured by T J Wassell and should be available from your dealer. In case of difficulty or trade enquiry contact Tim Wassell ."

Above c/o Norvil . http://www.norton.norvil.net/answers.htm Q & A.

I got my S silencers from Walridge, as far as I know they are Wassell but I'm sure Mike would tell you. They are quite nice to look at, no rough welds. My originals had rough looking welds at the reverse cone and at the header end too, plus they had a restricter in the pipe right about the widest part. I had some glass pack Hookers once and they were loud and needed the jetting reworked because they backfired like crazy, but since they rubbed on the ground they didn't stay on for more than a week. The Walridge ones seem fine, if a bit raspy with high revs.



The Hookers, they went on the right side. Bad idea.



Dave
69S

They are from Andover Norton. They are well finished, but just on the loud side. It doesn't seem they have any wadding in them to stop them resinating. They do look like the ones Norvil sell as well.
I want to replace the pair on my 850, which sound really good. They are loud when given some stick & the sound comes out of the rear of the silencer, not bashing around inside it. I bought these in the 90's & now reluctant to change them.
Got a new set of exhaust nuts as well - brass.

Any single carb conversion makes the exhaust note much more rorty with a distinct crack to it. I've had single Mk1 Amal, Mk 2 Amal, SU, and Mikuni VM. Don't ask me why it is, but it is. Have you converted to a single carb at the same time as you fitted the exhaust?

Still twin carbs.

I know what you mean. I have Togas, bought from Les E in 2000. They have no wadding and now I've fitted a PW3 cam they are very loud under load, really crackly. I was debating the Dunstall reps and was then tempted by a Dutch company selling OE Dunstalls still in their box at 305 euros delivered. I passed but they are still showing for sale. Does anyone here use the copies and do they sound any different to peashooters?

The quietest but still free flowing pea shooters I have used were from RGM and engraved Campbells, they were straight through but the tube louvres were pressed inwards facing towards the engine so they scooped the air and passed it into the outside chamber, there were 4 large holes near the rear for the air to return.

Flo,

Is your system fitted with a balance pipe at the header. That really reduces sound output?

Rich

If you have detachable end plates, you can stuff either exhaust wadding or roof insulation in there.
If you don’t, then a small amount stuffed in from the down pipe end might do the trick, but it will not last long.
HTH.

If I recall correctly from back in the day, a baffled exhaust pipe extension tip from an air-cooled VW motor placed in the crossover pipe would quiet the exhaust sound level.