Exhausts - Norton Manxman 650 1961 export model

A learned friend tells me this is a full bore exhaust at 1 5/8 inches from end to end. Not very common in UK.

Would one of the more common reduced diameter pipes, which suited the same port detail and silencer inlet, be suitable here. I'm thinking 99, 650ss and Atlas.?

Peter Holland

We have some 1"5/8 pipes on the Atlas that I once thought could be Manxman, very tight in the rose and with odd inward bends to amply clear the RC  but after looking at lots of early pictures ,the really  impressive MM pipes have a very gracefull sweep down from the ports and an equally impressive upward sweep with the silencer.I can well  imagine this would be very hard to make consistantly  by hand (which they were) and get to fit easily enough for a production line to function. 

My experience getting quality pipes for Norton's is a headache speaking from half a world away my experience has been disappointing, 10 years ago I purchased a set of header pipes for my 60SS from UK's second preferred supplier which wouldn't fit, I complained and the reply was " we have never had a problem before" 10 years later a friend purchased a set for his Mercury from the same vendor and encountered the same problems, as we are half a world away from the suppliers the cost of returning faulty products is prohibitive so when I order a product I expect it to be "right", add to this as I also have an Atlas which I believe was factory fitted with a large bore pipe with a kink in the right header, please recommend a supplier that supplies said pipes, sorry I am of the view that close is not good enough and that we are mere custodians for future generations therefor I would like to leave them as correct as possible. 

Hi Alan, I would get some SH orriginals refurbished and get a little more room in the rose nuts with a light cut on a lathe.

I would like to point out the aim of this particular forum.

 This Forum is designed to support this process by encouraging members to apply for parts to be commissioned by the club.

So if anyone wants to add their name to the list stating they too would like a particular part, or alternatively where such a part is available or could be made available, that would be really useful.

What this is NOT intended for is further discussion on the issues we already understand. This is why we started this process in the first place.

If only one person want a cosmetic item made, then it is unlikely to happen. If a number of people want an 'Off The Road' part made, then we will look to getting parts manufactured. I am sure everyone understands the difference in cost of a one off compared to a small batch.

Tony

Sometimes you have to feel sorry for those hard working people who are helping to run the NOC on our behalf. I note in the postings above one of them asking a simple question to which a yes or no answer or at worst a short sentence would have have been quite sufficient in terms of a response.

Instead, the lucky chap gets a lengthy speech that is worthy of a drunken best man at a wedding reception. NOC helper number 2 chips in by pointing out that this thread is actually designed for other purposes such as nominating parts that the NOC could get made and gets a verbal hand smacking the size of a Bible. 

I fully appreciate that Manxman exhaust pipes and silencers is an unknown territory for most people reading this thread but their chances of learning any facts about these parts are being swamped by the heaps of rubbish that keep being posted. Can somebody wake the moderator up please?

......seem to have been translated from English into some strange tongue and then back into English again.  I am an uninformed and disinterested party in this space.

Mark Twain did this with his Jumping Frog yarn:

"The Jumping Frog: In English, Then in French, Then Clawed Back Into a Civilized Language Once More by Patient, Unremunerated Toil"

If you are informed and interested enough to have closely studied  the early pictures of the bikes and seen them in the flesh,in the day, you may come to the conclusion that there were several versions of "orriginal" . Do the Factory drawings still exist.? What version of orriginal does Anna want to re-create?.I know Anna has access to orriginal silencers. But are these the same  ones that other owners want? Ditto pipe shape.

Thanks for your comments guys.

We know the part number of the pipes fitted to 1961 Manxman. From the parts list. See header post.

We know from the drawings 23432 and 23433 :-

That they appear full bore 1 5/8 ins. 

The RH pipe turns inward about 1 ins after leaving the exhaust port, then curves down. The LH just curves down.

The drawings suggest that the pipes are also used on 1961 model 99. (which market? UK? USA? other country?)

Do they look like this?   https://www.baxtercycle.com/product/nm234323/

Certainly, these look like the pipes in the drawings. Baxter thought so too.

And I believe the USA 1963/1964 models 650, 99, and Atlas might have used them too. Anyone got the parts lists for these models showing 23432 and 23433 headers?

I believe the UK models 650, 99, Atlas, in 1963/1964, used a reduced diameter exhaust pipe, with the same exhaust port and silencer inlet detail. 24020 and 24021.

The best suggestion I have for the owner who started this thread is that they fit the reduced diameter pipe, which Norton thought good enough for the later UK models and which was easier to produce reliably (by hand). or, if they really think the performance is going to be unacceptably downgraded, they wrap some heat resistant bandage over their rusty exhaust, perhaps with weld repairs, and continue at 107mph, or whatever maximum speed they enjoy.

I can't find anyone who has the full bore exhausts in stock.

Peter Holland

Hello Peter, yes I have a master parts list for 1966/ 67/ 68 and yes it lists 23432 & 23433 as exhaust pipe bare 650SS, Atlas, further more here in New Zealand in the 80's & 90's we were lucky enough to have a number of people importing a number of containers of British M/cycles mostly from USA, at one time I owned a '67 Atlas with about 7000 miles original paint and exhausts and yes they were large bore, all I really want is to find a supplier who can supply a quality set of the same [ large bore ] can you recommend a supplier please don't say RGM because both my friend and my self had bad experiences with sets for our 650's and as from here freight costs are too expensive to return faulty products, sorry it may sound if I am bleeting but as I have been restoring Norton's for a number of years it seems the problem seems to be getting worse.

If you fit the very curved Manxman pipes to a 650 ss  I think you will find there is no room for the silencer hangers needed for the SS silencers .That says to me that whatever the part numbers say the pipes must have been straightened out for the SS and Atlas.If you compare the look of Anna's bike to the factory Adds of the Manxman its clear that Anna:s  Atlas pipes  have a very different line and look. My very old 1"5/8 Atlas pipes have the Odd inward bends but then run straight back and only just allow the space for the Hanger brackets.I would bet I could make them fit (after a fashion!) a Manxman with its special silencers ,but it would look wrong.

OK, so who did not read my post:-

I would like to point out…

I would like to point out the aim of this particular forum.

 This Forum is designed to support this process by encouraging members to apply for parts to be commissioned by the club.

So PLEASE post on the appropriate forum, not this one.

Tony