Tach drive/exhaust conflict

I take it that the exhaust pipes on your Norton are the swept back type. If this is the case then fitting the alternative timing cover with the vertically mounted rev counter gearbox will still not help. See attachment......

Plan B.......fit an electronic rev counter instead.

Norton found the same problem with the first 650 machines way back in 1960 and as they were at that time making the exhausts they just bent the offside pipe in . You need a good pipe bender and a re-chrome or a set of 1 off stainless made. Its clear that whoever made those pipes did not do enough research.

Ernie,

My Mercury has standard exhaust pipes and the tacho drive has a Vertical alignment, as Phil Hannam mentions above. The attached photo shows my Mercury layout.

It looks as though you have the other type of timing cover that has the fixing holes at and angle, thus causing the cable to foul the exhaust pipe.

Philip.

Is the main component a single casting? Would it be possible to rotate the cylindrical part relative to the fixing flange so that the cable emerges vertically? Even if it's one piece, it could be possible by cutting and inserting a sleeve.

Previously ernie_olivo wrote:

Iâve installed an aftermarket roller bearing tachometer drive, and the tach cable line looks like trouble. I need some ideas and suggestions. Iâve added a picture.

Hi Ernie. Just this week I have fitted a pair of swept back pipes to my 56 Dommie 99. I was delighted to find that there was no conflict with my rev counter drive unit. The pipes were supplied by Classic Bikes and they appear to take a different route to the pipes in your attachment.

Hi Ron,I like the clutch cable run on your bike ,shame they did not do something similar on the later AMC box bikes. The port angles are very different on you head.

hello Norton Manxman right-hand downpipe was shaped so it misses this drive cable but these were only made for the Norton Manxmanhas it was the first to have a tachofitted as standardEQ but never reproduced as with the Plumstead ATLAS some crazy altered the angle of the timing case, so this meantno more bending of exhaustpipes which made life that more boring, yours anna j

Previously robert_tuck wrote:

Hi Ron,I like the clutch cable run on your bike ,shame they did not do something similar on the later AMC box bikes. The port angles are very different on you head.

Hi Robert. The clutch cable on the 56 Dommie ran through a duct that passed through the oil tank, very neat, but I expect that the additional cost of manufacturing the oil tank might have something to do with the design being discontinued. As regards your comments on the port angles: I have been trying to find more information about the head on my bike. I am begining to think that it is not the original but I don't know where to look or who to ask. The cast mark is: T2225 which doesn't seem to match the other info that I have found on Dominator heads. Sorry!, having delved into the clubs search function it appears that my head is one of the early alloy heads, first introduced in 1955, so I have no idea why the port angles look very different.

Ron.......the T2225 cylinder head would be correct for the age/year of your Norton. It differs from the later post 1960 88SS and 650 heads in having exhaust ports that face more to the front and also generally have a single carb mounting. I note that your engine has the adapter manifold that enabled the early twins to have a twin carb set-up. This included the factory built 99SS models up until 1962.

Your exhaust pipe is well clear of the timing cover but does this not cause an issue with the kick-start lever?

On the 650 Manxman and Mk 1 Atlas, the exhaust pipes were made with a series of complex bends to help tuck them back in towards and partly under the timing cover. Thus allowing the original shallow angle-cranked kickstart lever to be fitted. After these models, to save money, the exhaust pipes lost some of the bends. The kickstart then needed a larger cranked angle in order to clear the pipes. The attachments show the different exhaust angles and kickstarts. The Mk 2 Atlas pic shows the that the rev counter gearbox cable problem was known from the start.

Previously philip_hannam wrote:

Ron.......the T2225 cylinder head would be correct for the age/year of your Norton. It differs from the later post 1960 88SS and 650 heads in having exhaust ports that face more to the front and also generally have a single carb mounting. I note that your engine has the adapter manifold that enabled the early twins to have a twin carb set-up. This included the factory built 99SS models up until 1962.

Your exhaust pipe is well clear of the timing cover but does this not cause an issue with the kick-start lever?

On the 650 Manxman and Mk 1 Atlas, the exhaust pipes were made with a series of complex bends to help tuck them back in towards and partly under the timing cover. Thus allowing the original shallow angle-cranked kickstart lever to be fitted. After these models, to save money, the exhaust pipes lost some of the bends. The kickstart then needed a larger cranked angle in order to clear the pipes. The attachments show the different exhaust angles and kickstarts. The Mk 2 Atlas pic shows the that the rev counter gearbox cable problem was known from the start.

Hello Well with the Norton 650 Manxman there was a Second reason why the right hand down pipe was shaped on the right hand side and that is so the silencers fitted correctly ,has the Manxman silencer had a fixed mounting triangular bracket and the down pipe had to be in the right position for it too fit right as well has missing the tachometer drive cable So this was a nice peace of art work that looked the part and give the bike identity and the down pipes where full bore 1.5/8th at that and these were made in house at Bracebridge Street workshops with there craftsmen and craftsmen they really were something that is lacking to day yours anna J Dixon /p>

Previously ernie_olivo wrote:

Previously ron_tomkins wrote:

Previously ernie_olivo wrote:

Iâve installed an aftermarket roller bearing tachometer drive, and the tach cable line looks like trouble. I need some ideas and suggestions. Iâve added a picture.

Hi Ernie. Just this week I have fitted a pair of swept back pipes to my 56 Dommie 99. I was delighted to find that there was no conflict with my rev counter drive unit. The pipes were supplied by Classic Bikes and they appear to take a different route to the pipes in your attachment.

Hi Ron,

where is Classis Bikes located? They donât come up on Google.

my alternative might be to source a timing side cover with the vertical mounting holes.

thanks,

e

Hi again Ernie. Might have mislead you with Classic Bikes. It is actually: Classic Bike Shop. Their website is: www.classicbikeshop.co.uk.

Previously philip_hannam wrote:

Ron.......the T2225 cylinder head would be correct for the age/year of your Norton. It differs from the later post 1960 88SS and 650 heads in having exhaust ports that face more to the front and also generally have a single carb mounting. I note that your engine has the adapter manifold that enabled the early twins to have a twin carb set-up. This included the factory built 99SS models up until 1962.

Your exhaust pipe is well clear of the timing cover but does this not cause an issue with the kick-start lever?

On the 650 Manxman and Mk 1 Atlas, the exhaust pipes were made with a series of complex bends to help tuck them back in towards and partly under the timing cover. Thus allowing the original shallow angle-cranked kickstart lever to be fitted. After these models, to save money, the exhaust pipes lost some of the bends. The kickstart then needed a larger cranked angle in order to clear the pipes. The attachments show the different exhaust angles and kickstarts. The Mk 2 Atlas pic shows the that the rev counter gearbox cable problem was known from the start.

Many thanks for your input Philip. With respect to the kickstart issue, I have to admit that I was so chuffed with the fit of the pipes, relative to the rev counter, that I didn't look beyond. Anyway: hot footed it to the shed and lashed up the exhaust system with wire and tie tags and I appear to have a good 10mm clearance. So relieved that I don't have to consider reshaping the kickstart or extending its splined boss. Thanks again. Ron.