Dominie Exhaust Silencers

Hello John - Your parallel silencers could well be a reproduction of the first SS types fitted for a few years to the 88 and 99 SS. The internals are very like the later 650SS silencer which were quite loud. There was a straight-through fluted tube running the whole length terminating in a large flat ring with a tiny hole ( a bit like a huge penny washer ). People used to drill out that ring ( or blow them out ! ) and then they were very loud indeed. Your model would have probably had the flatter cigar type silencer which was very constrictive and very quiet and no sign of the big washer looking from the rear. Image shows 88SS silencer from 1960. Cheers, Howard

Those are correct, Howard IMO.

You can see mine on a recently restored 1960 99 if you like.

On the NE Section VMCC website: Neil's Norton Notes.

Or 1960 Dominator 99 restoration should get you there.

Howards picture shows the correct style silencers for 1960 but they are pattern replacements with a visible seam at the end cone. They will be louder than the orriginals which had glass fibre sound absorption packing. However this is a good thing these days to wake up dozey car drivers.The header pipes are incorrect as they are made to fit the non std ss head. The correct pipes are very hard to find ,and should drop down at the port and have a nice regular curve and a small kick up under the gearbox to give a nice line to the silencer which should be high enough to only just allow wheel axle removal.

I think when I bought my silencer from Armours years ago, I asked about glass fibre wadding. I'm pretty sure they said that it would have been used originally but it slows down the rate the box heats up, so it encourages condensation and greatly shortens the life as the box rots through from inside far more quickly with it than without. Their customers don't appreciate that. So maybe new replacement silencers are much noisier than the originals?

I have these on my 99 and yes they are a bit rorty but its a nice noise.I pour engine oil into silencers and rotate then drain . This protects from rust ,the chrome now goes first as its not the best.I give the silencers a wipe with an oily rag after they have dried off from a wet ride.I had to dent mine to get close to the frame and to give clearance to stand. A siamese system works well as it heats up the system and burns condensation,the pair of silencers are interchangeable so last twice as long. Packing sleeves are availiable from car accessory shops.

This is all a bit confusing..

Howard's picture shows the input pipe central to the tubular (cylindrical) box. That shape (or something similar) appears in some books for De Luxe models usually in 1961 (and possibly the Manxman!). But the Motor Cycling test report for 88SS has the much more usual oval section box with the inlet at its bottom - like the ones on Neil's web site. And these are handed - so a matched pair will only provide one for a siamesed system because the bolt holes are on the inside face. So not interchangeable.

Bacon's Norton Twins Restoration has contemporary pictures with the bottom entry oval section pipes appearing on 99's before 1960.

Maybe they used the Manxman pipes on the De Luxe - and perhaps some also went randomly on other bikes at about that time (1961)?

From a distance Manxman silencers look similar to the Dommy tubular ones. but they were very different ,designed to allow less restricted breathing and were made in house ,which was not usual.These are not made by anyone now.The Tubular "cheroot" silencer was fitted to the splayed carb 88/99 ss as well as the DL, the Navigator,the Jubilee and electra from 59 into the early 60's. They also can be made to fit 250/350 Ducatis! and work better than the orriginals while looking very similar.Replacement "cheroots" were not so easily found so the offset silencers as fitted to later SS models were often subtituted, they were also cheap from Dunstall who stripped them off.

Thanks, Robert.

If it helps I attach a photo taken of my 1963 88SS - bought from the first owner by me Feb 1968 - pic taken by me June 1968.

I put on the gaiters and all else is as I received the bike. I think the tank was a repaint...dent and all! Silencers and pipes I'm sure were original and of the time also with a dent in the N/S pipe. Pipes were reduced diameter where they left the head (note also the slight upturn of the pipe end giving a good high line). Can't remember if they had the disc and small hole type baffle but do remember that the chromed metal of the outer skin continued round at the exit end and continued back inside towards the baffles forming a 'tube in tube'. I have a 68 Commando bought a couple of years ago (an import to Australia from the states) and the silencers may not be original 1968 but look very similar except the outer chromed skin folds back inside towards the baffles and is then cut showing and allowing you to touch the inside of the outer skin.

Regards Patrick.

A pic also of the 68 Commando silencer but of course with no provenance... FYI

Interesting but 63 is not 60 and things had changed by then.

That seat cover takes me back. Didn't they all have them then? I went wild and patriotic and replaced my cheap black plastic universal cover with a cheap tartan plastic universal one. Made all the difference. That and the racing headlight bulb.

If we are recreating an era, very few bikes stayed standard for any length of time. Perhaps there is a place for authentically butchered bikes with alloy guards, megaphones etc. and all done on the cheap.

My 1960 99 had standard SS type silencers on it when I bought it in 1969. Were they original? Perhaps.

Patricks 88SS would be my all time favourite Norton, I had an unmolested 1961 88 in 63 and it had cheroot silencers, I blew the fibreglass linings out on the MI on my commute from Dulwich to Burnley Lancs. Out on the Rudge today ,a bit too cold

I believe Howard's attachment shows the correct silencers. According to Roy Bacon in his book Norton Twin Restoration the central inlet silencer was introduced in 1960 for the standard and deluxe 88 and 99 and continued to the end of production.

The offset inlet silencer was used for the 650 in 1961, and the 88SS and 650SS in 1962, and the right-side silencer was used for siamezed systems in 1961-62. they were then used on the Atlas and the first Commandos.

My 1963 88 had offset inlet silencers from new (see attachment), but it's unusual in being a police bike and has an SS crank, though single carb and standard head. I've civilianized it and fitted central inlet silencers from Armours, HDSN1.

Thats a cracker Rob, all the best bits , and very easy to live with. Far too good for the fuzz, How does it look now?.

Previously robert_tuck wrote:

Thats a cracker Rob, all the best bits , and very easy to live with. Far too good for the fuzz, How does it look now?.

VMCC South Lakes Mountain Weekend, September 2015 (photography by Colin Steer)

As I thought ,a great bike to share,not too fast but smooth, a comfy bike for a pillion with extra security for the passenger in the topbox backstop and sensible footrest positions .My sort of bike .

Adding a few points of interest to this thread. Checkout the attachment with details from the 1963 Norton sales brochure. Both UK and export versions show the same pictures. Note the differing silencers and the slight kick-up angle of the Standard 88 version. The Model 88SS bike keeps the off-set 650 style silencer. The other point worth noting is the underslung rear brake lever. Confirmed in Rob's period photo. When I tried to replicate this far more efficient arrangement on my own Atlas, it did not work due to the brake rod fouling the rear footrest.

So John, now you know!, Unless you are likely to change the cylinder head what you have now is more like the orriginal fitment than anything else you could buy. As for buying pipes that actually fit the bike That was a problem for years,a rough fit was the result of the same pipes being supplied to fit the 88 and taller 99 engine.It was not always like this. It would be nice if someone supplied a siamese that fits ,perhaps the RGM one has improved over the years.They at least have the right attitude.

Phil's picture of the standard 88 is interesting. I didn't know about the slight kick up of the exhaust. When I rebuilt my Dommie in the noughties (it was a slow job), the first exhaust pipes I got were from a certain Bxxxxx Jxxx at Stafford show. They didn't fit, but I've always wondered what they do fit, as they were sold for Norton 88 and 99, I believe. Maybe they will suit my friend's 1960 88. t would be nice to know, as they're brand new and could be useful to someone. Even the pipes I ended up with needed a bit of "adjustment" to the left one to avoid fouling the primary chaincase cover.

I notice the silencer has a bit more of a taper at both ends than the Armours offering, but I suppose nowadays we have to make do with nearly right.

For Robert and others who like looking at pictures, I attach one of my Dommie as I restored it in 2009 before the original picture turned up from the last policeman to ride it. It appeared in the NOC calendar as Miss November 2011.

Very nice, not sure about the lunch box in the tank,and where do you keep the glasses for the brass cocktail shaker ?. To nit pick, seems to have an odd brakelight switch and the footrest/brake angle is very low,Daddy long legs??.

Nitpicking? I'll say!

The footrests are where I like them, I'm not of restricted stature. I can't even see the brake light switch in the photo clearly, but it was probably a springy universal type before I got the correct square switch.

My initial researches suggested that Kent police Atlases had cocktail shakers, but when I got the photo of MOO as a young Norton I discovered City of London police are teetotal.

Superb pictures of a superb looking bike. The original picture is interesting - presumably somewhere in London; Norton motorbike (British), Austin A35 (British), Morris Minor (British), Ford Minibus (British), Austin Cambridge (British) and a policeman(British? He looks the part).

Not a single Honda or Mercedes in sight.

I have an Oxford Ist in Nitpicking!, and have barely scratched the surface,however you have scored max points with those header pipes which are either orriginals (very rare ) or excelent copies with the proper bends and kick up. Wish I had some.

Previously patrick_mullen wrote:

Superb pictures of a superb looking bike. The original picture is interesting - presumably somewhere in London; Norton motorbike (British), Austin A35 (British), Morris Minor (British), Ford Minibus (British), Austin Cambridge (British) and a policeman(British? He looks the part).

Not a single Honda or Mercedes in sight.

Summer 1963, Mile End Road, London, by the canal bridge (means nothing to me, I'm from the Norf.) The little girl was lost and being looked after by a real British bobby. The photo was in the East London Gazette.

From a distance Manxman silencers look similar to the Dommy tubular ones. but they were very different ,designed to allow less restricted breathing and were made in house ,which was not usual.These are not made by anyone now.The Tubular "cheroot" silencer was fitted to the splayed carb 88/99 ss as well as the DL, the Navigator,the Jubilee and electra from 59 into the early 60's. They also can be made to fit 250/350 Ducatis! and work better than the orriginals while looking very similar.Replacement "cheroots" were not so easily found so the offset silencers as fitted to later SS models were often subtituted, they were also cheap from Dunstall who stripped them off.

And this machine in my 1960 catalogue has the smooth look silencer fitted these were made in house at Bracebridgestreet and did not have a small fold on the underside like the after market one's have. The Originals had a weld on the underside and was chromed after this, I do have an originalsilencer. you will find there heavier than anything made by Armours silencers. now Not making silencer in house. And now having them made else where !!! yours anna j