99S differences

hello do you meen 99c ,I have not heard of a 99s ,but have heard off the 99ss built from april1961 to sep1963 this engine shares the camshaft and pushrods and followers from the Norton Manxman 650

Back in 1965 John Hudson referred to my own 1959 '99' as a "99 Special" because it had quite a few of the optional factory extras, like large inlet valves, twin carbs, HC pistons, chrome mudguards, full rear chainguard etc. I wrote to him with many technical queries during its first strip and rebuild. His own view was that twin carbs weren't worth the bother but small-bore siamese pipes with an "SS silencer" gave a performance increase on the 99. If your engine is a "14P" (1959 Model 99) maybe they labelled it because of the ex-works mods? Cheers, Lionel

Hi again, another query , my 99SS engine should have the camshaft etc of the Manxman, should it also have an SS head , by the NOC , May issue , the head information in it says SS heads have horizontal mounting studs, mine has the vertical stud configuration, have I the wrong head please.

-------------------------------------

The factory built 99SS models, that were catalogued and available to Joe Public for a little under two years,were all stamped with 99SS on the back of thecrankcases. As opposed to just 99 or 99C on the other 600cc engines.

As part of the deal, you got an SS camshaft from the 650 engine as well as 650 barrels, 650pushrods, twin Monobloc 376 carbs plus the option of a siamesed or standard exhaust. The most notable diffference between the 650SS and 99SS was the cylinder head. The 650 had the new splayed exhaust and twin carb job with horizontal carb mounting studs. The 99SS was sold with the old standard 1960 style 99 head with the old exhaust ports and mounting studs for the 2 into 1 car manifold. Although, mounted in this area was now a special adapter which fitted between the head and allowed the use of twin carbs. Strangely, in this head you had the bigger inlet valves of the 650 and some earlier 88 &99 heads plus the shorter but stiffer 650 type of valve springs. Coil ignition was used for these engines.

Of interest, the 1962 sales brochure shows the 88SS wearing the 650 type of SS cylinder head but mentions that the 99SS has the standard head. John Hudson once told me that the last couple of dozen 99SS bikes produced by the factory were actually fitted with the SS head but were never released to dealers as it was quickly realised that any of the previous 99SS bikes, stillavailable,would then never sell. Which begs the question of what happened to these proper 99SS specials? Were the bikes re-engined with650SS motors and sold as such or just dismantled for spares?

Hopefully attached is a photo of the 1959 to 1963 cylinder head usedon the99SS engines. Both the road and off-road Nomad version had this motor but with carb, ignition and other small differences.

Previously wrote:

Hi again, another query , my 99SS engine should have the camshaft etc of the Manxman, should it also have an SS head , by the NOC , May issue , the head information in it says SS heads have horizontal mounting studs, mine has the vertical stud configuration, have I the wrong head please.

---------------------

The factory built 99SS models, that were catalogued and available to Joe Public for a little under two years,were all stamped with 99SS on the back of thecrankcases. As opposed to just 99 or 99C on the other 600cc engines.

As part of the deal, you got an SS camshaft from the 650 engine as well as 650 barrels, 650pushrods, twin Monobloc 376 carbs plus the option of a siamesed or standard exhaust. The most notable diffference between the 650SS and 99SS was the cylinder head. The 650 had the new splayed exhaust and twin carb job with horizontal carb mounting studs. The 99SS was sold with the old standard 1960 style 99 head with the old exhaust ports and mounting studs for the 2 into 1 car manifold. Although, mounted in this area was now a special adapter which fitted between the head and allowed the use of twin carbs. Strangely, in this head you had the bigger inlet valves of the 650 and some earlier 88 &99 heads plus the shorter but stiffer 650 type of valve springs. Coil ignition was used for these engines.

Of interest, the 1962 sales brochure shows the 88SS wearing the 650 type of SS cylinder head but mentions that the 99SS has the standard head. John Hudson once told me that the last couple of dozen 99SS bikes produced by the factory were actually fitted with the SS head but were never released to dealers as it was quickly realised that any of the previous 99SS bikes, stillavailable,would then never sell. Which begs the question of what happened to these proper 99SS specials? Where the bikes re-engined with650SS motors and sold as such or just dismantled for spares?

Hopefully attached is a photo of the 1959 to 1963 cylinder head usedon the99SS engines. Both the road and off-road Nomad version had this motor but with carb, ignition and other small differences.

Hello Phil, the 650 barrels are 7mm longer than the 99 and the 99ss have ak2FCmagneto. I owned one back in the 70s and raced it too- I thrashed the nuts off it, but it just came back for more - what a bike! I wish I had NOT SOLD ITwhat aFOOL I was! Yours Anna J dixon

Just to add to the confusion!! No-one has mentioned a year date for Adrian's engine yet but, from the 2 engine numbers mentioned in this thread, both must be later than 1960 as they don't have a year letter. The lastletter usedwas "R" for 1960.

Phil, I wasn't aware that an SS head like your photo was available from 1959 - it's not in my Parts List book for that year or 1960, 1961/62, but I haven't got any SS Parts Lists.The 1959 listonly has the optional equipment of a head with larger inlet valves - subsequently made standard from 1960-on. Mine is a standard looking head without the machined-off side fins but with large inlets; Part No.21325A. The same head was also available for the 88 and was normally fitted with twin carbs and high comp pistons. This would have made a "pseudo-SS"! Did the one in your photo have wider-splayed exhaust ports? It doesn't look like it.

As the parts from this era can be pretty much "mix-&-match" it migh be difficult to estimate the actual capacity of an engine without measuring the bore size! Even then it's not clear cut as a 500cc 88 may have been bored out to 67mm and the standard bore size of a 99 is 68mm - accurate measurement will be essential.

In my correspondence with John Hudson in 1965/66 he never mentioned an SS version at all!

Previously wrote:

Just to add to the confusion!! No-one has mentioned a year date for Adrian's engine yet but, from the 2 engine numbers mentioned in this thread, both must be later than 1960 as they don't have a year letter. The lastletter usedwas "R" for 1960.

Phil, I wasn't aware that an SS head like your photo was available from 1959 - it's not in my Parts List book for that year or 1960, 1961/62, but I haven't got any SS Parts Lists.The 1959 listonly has the optional equipment of a head with larger inlet valves - subsequently made standard from 1960-on. Mine is a standard looking head without the machined-off side fins but with large inlets; Part No.21325A. The same head was also available for the 88 and was normally fitted with twin carbs and high comp pistons. This would have made a "pseudo-SS"! Did the one in your photo have wider-splayed exhaust ports? It doesn't look like it.

As the parts from this era can be pretty much "mix-&-match" it migh be difficult to estimate the actual capacity of an engine without measuring the bore size! Even then it's not clear cut as a 500cc 88 may have been bored out to 67mm and the standard bore size of a 99 is 68mm - accurate measurement will be essential.

In my correspondence with John Hudson in 1965/66 he never mentioned an SS version at all!

Previously wrote:

Previously wrote:

Hi Adrian, As this thread is still ongoing. The attached pic of my engine block may help.

I have rebuilt this engine from sump plug to head steady and at the time tried to pin down details of the spec. There seems to be quite a bit of âmisinformationâ to put it politely, around.

The 99ss 600cc had coil ignition, as far as I can see externally, the basic 600ss engine will look the same as standard of that year. You need to get inside to check things out, the camshaft was the main difference. Valve timing can be checked but unless you are up on 50/74/82/42 and things its not easy.

Ron.

I am unsure as to the cc , mainly for insurance reasons, I just always thought that 88 was 500cc, 99 was 600cc and then the SS was a 650 , also this is registered asmid 70's at present and needs to be reallocated a correct year reg number so i do need to sort the cc first, cam timing mathematis, like all mathematics, way beyond me, but i can build engines following a fewtiming dots, etc, (have a desm ducatitoo) my engine number is 99SS 7473, thanks for your input.

Previously wrote:

Previously wrote:

Previously wrote:

Hi Adrian, As this thread is still ongoing. The attached pic of my engine block may help.

I have rebuilt this engine from sump plug to head steady and at the time tried to pin down details of the spec. There seems to be quite a bit of âmisinformationâ to put it politely, around.

The 99ss 600cc had coil ignition, as far as I can see externally, the basic 600ss engine will look the same as standard of that year. You need to get inside to check things out, the camshaft was the main difference. Valve timing can be checked but unless you are up on 50/74/82/42 and things its not easy.

Ron.

I am unsure as to the cc , mainly for insurance reasons, I just always thought that 88 was 500cc, 99 was 600cc and then the SS was a 650 , also this is registered asmid 70's at present and needs to be reallocated a correct year reg number so i do need to sort the cc first, cam timing mathematis, like all mathematics, way beyond me, but i can build engines following a fewtiming dots, etc, (have a desm ducatitoo) my engine number is 99SS 7473, thanks for your input.

Hi Adrian, I think you have worked out that the extra 50cc of the 650 comes from length of the stroke,

600cc Bore 68mm Stroke 82mm. 650cc Bore 68mm Stroke 89mm.

If your engine is clearly marked 99 itâs a 597cc engine. The head type will not change its displacement.

Itâs very unlikely that someone would have changed the crankshaft, this is where the extra stroke length is generated (that is 3.5mm up & 3.5mm down) and hence the extra 7mm in barrel length. But this extra length is not visible on the outside of the engine.

The number that is shown with the 99SS is not what is generally given as the engine No I would like to know what it is, in my case its not the works build No.

The number needed for the VOSA Doc will be the number on the drive side. You should be able to trace more details of the original bike from this.

Ron.

I am unsure as to the cc , mainly for insurance reasons, I just always thought that 88 was 500cc, 99 was 600cc and then the SS was a 650 , also this is registered asmid 70's at present and needs to be reallocated a correct year reg number so i do need to sort the cc first, cam timing mathematis, like all mathematics, way beyond me, but i can build engines following a fewtiming dots, etc, (have a desm ducatitoo) my engine number is 99SS 7473, thanks for your input.

Evening Gents,

You seem to be working it out.

Adrian, If you are able to turn the engine, you could confirm the stroke with a 6" length of welding rod. Another pair of hands would be helpful.

Rest the rod on top of the piston, turn the engine until the rod stops descending. Mark the rod with a fine felt tip pen, level with the top of the plug thread. Turn the engine again until the rod stops rising and make another mark in the same way.

You'll most likely have 82mm!

With the 650's (also 750's & 850's) having 7mm more stroke, also larger big end journals, the crankcases had to be enlarged to clear the big ends. I'm attaching a picture of the area of the drive side crank case where the difference is obvious, when compared with 600cc crankcases.

The steel rule is resting on the enlarged area of the 650 case.

I'm also experimenting with the text on this website to see if I can send more legible messages. So please bear with me if that doesn't work!

Paul.

I wrote a few minutes ago

Adrian, If you are able to turn the engine, you could confirm the stroke with a 6" length of welding rod. Another pair of hands would be helpful.

On second thoughts, maybe a 12" length of welding rod would be better. Certainly a lot easier.

Paul.

Previously wrote:

Adrian Gidney wrote Thursday 08:09

I am unsure as to the cc , mainly for insurance reasons, I just always thought that 88 was 500cc, 99 was 600cc and then the SS was a 650 , also this is registered asmid 70's at present and needs to be reallocated a correct year reg number so i do need to sort the cc first, cam timing mathematis, like all mathematics, way beyond me, but i can build engines following a fewtiming dots, etc, (have a desm ducatitoo) my engine number is 99SS 7473, thanks for your input.

Evening Gents,

You seem to be working it out.

Adrian, If you are able to turn the engine, you could confirm the stroke with a 6" length of welding rod. Another pair of hands would be helpful.

Rest the rod on top of the piston, turn the engine until the rod stops descending. Mark the rod with a fine felt tip pen, level with the top of the plug thread. Turn the engine again until the rod stops rising and make another mark in the same way.

You'll most likely have 82mm!

With the 650's (also 750's & 850's) having 7mm more stroke, also larger big end journals, the crankcases had to be enlarged to clear the big ends. I'm attaching a picture of the area of the drive side crank case where the difference is obvious, when compared with 600cc crankcases.

The steel rule is resting on the enlarged area of the 650 case.

I'm also experimenting with the text on this website to see if I can send more legible messages. So please bear with me if that doesn't work!

Paul.

Aha Ron! The plot thickens! My 1959 parts list PS 206 has that cylinder head in the 'Optional Equipment' section at the back (red type-face). This one is presumably what my bike has, although I have no idea whether the inlet ports are at wider centres than the earlier 'standard' head - haven't got one to compare it with! Apparently it was available from some time in 1958 (Steve Wilson says from May). Then it was supposedly fitted as standard from 1960 - YET there is another head mentioned in literature which says/implies they had another, differentnew head in 1960! Steve Wilson taks about the milled off crosses between the exhaust and inlet rocker spindleplates.Mick Walker's book just says it had improved cooling by way of "increased and deeper finning". It sounds as if they are talking about two different heads - one from 1958 and one from 1960. The "new" head 21325A from the 1959 optional list and the "new" head with milled off sections are obviously different headsyet the head assembly with valve guides - p/n R12-2/136 - is the same as the one listed in both PS 208 for 1960, and PS 214 for 1961/62!

TheSupplementary Spare Parts List PS 208refers to PS 206 (1959) for any parts not listed. It doesn't list a bare cylinder head but it lists the large inlet valve as per the 1959 optional version - p/n 17221 - as you would expect. By "Elementary Sherlock Holmes deduction" using these lists, the head listed as extra for 1959 and standard for 1960-62 should be the same!

Confused? You should be!

Re: camshafts - I've not even gone there but I was told by John Hudson that mine had the Daytona type with Quietening Ramps ("QR"). This is confirmed in many sources as the issue for the 1959 99. Like a fool I sold the original camshaft to Barry Lawton (Syd's son) who wanted to use it in his Domiracer on the I.o.M.! Dunno if he won any races with it! I then bought a cheap 88 engine (for £5!)which had an SS camshaft in! I used that one in my 99 but keptmy originalradius-based cam followers - couldn't afford a set of new SS ones! I have since had them re-faced flat by the same engineering workshop that rebored my 99 barrels (and who do work for Norman White at Thruxton). So- IF I reassemble the engine with what I've got, it will be an SS spec cam & followers but not with twin carbs - I really can't be ar*ed to go that route!

Cheers, Lionel

Previously wrote:

Aha Ron! The plot thickens! My 1959 parts list PS 206 has that cylinder head in the 'Optional Equipment' section at the back (red type-face). This one is presumably what my bike has, although I have no idea whether the inlet ports are at wider centres than the earlier 'standard' head - haven't got one to compare it with! Apparently it was available from some time in 1958 (Steve Wilson says from May). Then it was supposedly fitted as standard from 1960 - YET there is another head mentioned in literature which says/implies they had another, differentnew head in 1960! Steve Wilson taks about the milled off crosses between the exhaust and inlet rocker spindleplates.Mick Walker's book just says it had improved cooling by way of "increased and deeper finning". It sounds as if they are talking about two different heads - one from 1958 and one from 1960. The "new" head 21325A from the 1959 optional list and the "new" head with milled off sections are obviously different headsyet the head assembly with valve guides - p/n R12-2/136 - is the same as the one listed in both PS 208 for 1960, and PS 214 for 1961/62!

TheSupplementary Spare Parts List PS 208refers to PS 206 (1959) for any parts not listed. It doesn't list a bare cylinder head but it lists the large inlet valve as per the 1959 optional version - p/n 17221 - as you would expect. By "Elementary Sherlock Holmes deduction" using these lists, the head listed as extra for 1959 and standard for 1960-62 should be the same!

Confused? You should be!

Re: camshafts - I've not even gone there but I was told by John Hudson that mine had the Daytona type with Quietening Ramps ("QR"). This is confirmed in many sources as the issue for the 1959 99. Like a fool I sold the original camshaft to Barry Lawton (Syd's son) who wanted to use it in his Domiracer on the I.o.M.! Dunno if he won any races with it! I then bought a cheap 88 engine (for £5!)which had an SS camshaft in! I used that one in my 99 but keptmy originalradius-based cam followers - couldn't afford a set of new SS ones! I have since had them re-faced flat by the same engineering workshop that rebored my 99 barrels (and who do work for Norman White at Thruxton). So- IF I reassemble the engine with what I've got, it will be an SS spec cam & followers but not with twin carbs - I really can't be ar*ed to go that route!

Cheers, Lionel

Hello Lionel.

Yep got it, err well may be not! Iâve sent a pic of my 1961 99 engine. This is a R12-2/136 cylinder head 99.9% certain. The milled section between the rocker spindles can be seen. Extra cooling fin area, easiest clue to spot is the finning above the exhaust ports is now all horizontal. Itâs not that obvious but the inlet manifold fixings are just that bit further way from the edge of the enlarged ports. I think this fits Steve Wilsonâs / Mick Walkerâs description.

If you can get hold of a set of 650cc pushrods this would be a nice upgrade, they would be used oneâs, not available new but they are very nice lightweight hollow aluminium (special grade) tapered each end, people say barrel shape. You know, red line 8000rpm.

Regards Ron.

Hello Lionel.

Yep got it, err well may be not! Iâve sent a pic of my 1961 99 engine. This is a R12-2/136 cylinder head 99.9% certain. The milled section between the rocker spindles can be seen. Extra cooling fin area, easiest clue to spot is the finning above the exhaust ports is now all horizontal. Itâs not that obvious but the inlet manifold fixings are just that bit further way from the edge of the enlarged ports. I think this fits Steve Wilsonâs / Mick Walkerâs description.

If you can get hold of a set of 650cc pushrods this would be a nice upgrade, they would be used oneâs, not available new but they are very nice lightweight hollow aluminium (special grade) tapered each end, people say barrel shape. You know, red line 8000rpm.

Regards Ron.

Previously wrote:

Previously wrote:

Previously wrote:

Previously wrote:

Previously wrote:

Hi Adrian, As this thread is still ongoing. The attached pic of my engine block may help.

I have rebuilt this engine from sump plug to head steady and at the time tried to pin down details of the spec. There seems to be quite a bit of âmisinformationâ to put it politely, around.

The 99ss 600cc had coil ignition, as far as I can see externally, the basic 600ss engine will look the same as standard of that year. You need to get inside to check things out, the camshaft was the main difference. Valve timing can be checked but unless you are up on 50/74/82/42 and things its not easy.

Ron.

I am unsure as to the cc , mainly for insurance reasons, I just always thought that 88 was 500cc, 99 was 600cc and then the SS was a 650 , also this is registered asmid 70's at present and needs to be reallocated a correct year reg number so i do need to sort the cc first, cam timing mathematis, like all mathematics, way beyond me, but i can build engines following a fewtiming dots, etc, (have a desm ducatitoo) my engine number is 99SS 7473, thanks for your input.

Hi Adrian, I think you have worked out that the extra 50cc of the 650 comes from length of the stroke,

600cc Bore 68mm Stroke 82mm. 650cc Bore 68mm Stroke 89mm.

If your engine is clearly marked 99 itâs a 597cc engine. The head type will not change its displacement.

Itâs very unlikely that someone would have changed the crankshaft, this is where the extra stroke length is generated (that is 3.5mm up & 3.5mm down) and hence the extra 7mm in barrel length. But this extra length is not visible on the outside of the engine.

The number that is shown with the 99SS is not what is generally given as the engine No I would like to know what it is, in my case its not the works build No.

The number needed for the VOSA Doc will be the number on the drive side. You should be able to trace more details of the original bike from this.

Ron.

. I attach a pic of my inlet manifold but I canât guarantee itâs a genuine Norton part, no part No. Unfortunately there are two sizes.

hope that manifold is notresting on the wifes best table cloth ???, ha ha....thanks very much i will inspect mine in great detail tomorrow to compare.

Previously wrote:

Previously wrote:

Just to add to the confusion!! No-one has mentioned a year date for Adrian's engine yet but, from the 2 engine numbers mentioned in this thread, both must be later than 1960 as they don't have a year letter. The lastletter usedwas "R" for 1960.

Phil, I wasn't aware that an SS head like your photo was available from 1959 - it's not in my Parts List book for that year or 1960, 1961/62, but I haven't got any SS Parts Lists.The 1959 listonly has the optional equipment of a head with larger inlet valves - subsequently made standard from 1960-on. Mine is a standard looking head without the machined-off side fins but with large inlets; Part No.21325A. The same head was also available for the 88 and was normally fitted with twin carbs and high comp pistons. This would have made a "pseudo-SS"! Did the one in your photo have wider-splayed exhaust ports? It doesn't look like it.

As the parts from this era can be pretty much "mix-&-match" it migh be difficult to estimate the actual capacity of an engine without measuring the bore size! Even then it's not clear cut as a 500cc 88 may have been bored out to 67mm and the standard bore size of a 99 is 68mm - accurate measurement will be essential.

In my correspondence with John Hudson in 1965/66 he never mentioned an SS version at all!

Hi.Lionel, My 99ss left the factory in June 1961 ( Slimline ). Your suppositions for the Sports Special are as mine.

From my Original Parts Book 1961/62, PS214 that includes supplementary list for 88SS 99SS & 650ss + the Optional Equipment list.

Part No :- " 21325A Polished cylinder head, complete with valve guides and large inlet valve seat insert ". For Models 88, 99. STD and D/L Price £20 2 6

Part No :- 18542 Inlet manifold (for dual carburettor fixing) For Model 88 99 STD Price £1 17 2Also listed are various High Compression pistons 8.9 9.45 10.2

Now, like you I think that this upgrade was the basis of the New Head introduced in 1960.

This is where the inlet manifold fixing centres changed, 1.5in to 1.625in

Part No :- R12-2 /136. The large inlet valve ( Known as V195 ) now standard. 22707K cast in head.

From the Parts List I can see the difference in various 99SS parts.

Cylinder Head. same part no for 99 & 99SS £18 18 0.

Valves, no different Number given, assume the same.

Cylinder Barrel 99 = 22709. 99SS = 22709D. By the way 650SS = 23263

Valve Springs 99 = 19302inner 19303outer. 99SS = 22839 inner 22838 outer. Note. same as 650SS.

Push Rods 99 = M14/82 IN M14/82 EX. 99SS = S650/82 IN S650/82EX Note. same as 650SS.

Camshaft 99 = 21225 99SS = 22729 Note same as 650SS

A question. I think we agree that models share some parts, but does the 99SS share 650SS parts or does the 650SS share 99SS parts. Which came first.

Ron C.

hello all 650 Manxman Was the First to have the Downdraft Cylinder head First one built was on NOVEMBER 7TH 1960 MY Manxman was Built on the 28th december 1960 and as not got a R stamped on As it was a Export Bike The Cylinder Head Part Number is s650/136, barrel part number 23263, 650 as 3.5 mm extra bottom flange,And wider cutout for connecting rod ,piston where made by BHB ,My manxman its Standard bore part number for piston are 23268LH and23269RH Supplied over sizes +010 +020 +030 camshaft part number 22729 hope this helps Yours Anna J Dixon

Previously wrote:

Just to add to the confusion!! No-one has mentioned a year date for Adrian's engine yet but, from the 2 engine numbers mentioned in this thread, both must be later than 1960 as they don't have a year letter. The lastletter usedwas "R" for 1960.

Phil, I wasn't aware that an SS head like your photo was available from 1959 - it's not in my Parts List book for that year or 1960, 1961/62, but I haven't got any SS Parts Lists.The 1959 listonly has the optional equipment of a head with larger inlet valves - subsequently made standard from 1960-on. Mine is a standard looking head without the machined-off side fins but with large inlets; Part No.21325A. The same head was also available for the 88 and was normally fitted with twin carbs and high comp pistons. This would have made a "pseudo-SS"! Did the one in your photo have wider-splayed exhaust ports? It doesn't look like it.

As the parts from this era can be pretty much "mix-&-match" it migh be difficult to estimate the actual capacity of an engine without measuring the bore size! Even then it's not clear cut as a 500cc 88 may have been bored out to 67mm and the standard bore size of a 99 is 68mm - accurate measurement will be essential.

In my correspondence with John Hudson in 1965/66 he never mentioned an SS version at all!

hello the 88,500cc barrel as 8 cooling fins and 99/650 as 9 cooling fins the 650 asa long flange at the bottom for the longer stroke the 99ss crankcase are the same as 650 Manxman ,not all 650s where SS there was a DE-LuXed model and a standard model from October 1961 to august 1962 as the 99 models allso ended in 1962 as Bracebridge Street works closed and every thing moved to Plumsted and wolverhamton AMC works hope this helps yours anna j dixon

Previously wrote:

Previously wrote:

Hi Adrian, As this thread is still ongoing. The attached pic of my engine block may help.

I have rebuilt this engine from sump plug to head steady and at the time tried to pin down details of the spec. There seems to be quite a bit of âmisinformationâ to put it politely, around.

The 99ss 600cc had coil ignition, as far as I can see externally, the basic 600ss engine will look the same as standard of that year. You need to get inside to check things out, the camshaft was the main difference. Valve timing can be checked but unless you are up on 50/74/82/42 and things its not easy.

Ron.

I am unsure as to the cc , mainly for insurance reasons, I just always thought that 88 was 500cc, 99 was 600cc and then the SS was a 650 , also this is registered asmid 70's at present and needs to be reallocated a correct year reg number so i do need to sort the cc first, cam timing mathematis, like all mathematics, way beyond me, but i can build engines following a fewtiming dots, etc, (have a desm ducatitoo) my engine number is 99SS 7473, thanks for your input.

hello your engine number this stamped at the front left hand side just above the end of the camshaft tunnel and shud start with 96xxx or 97xxx so theres number missing and the 99ss was only built for 14 months ,march 1961 to august 1962 yours anna j dixon

Previously wrote:

my engine is stamped 14 and its number is 98123, front left hand side, the 99ss 7473 being stamped to the rear just inboad of the crankcase breather outlet. never got around to any measuring this weekend , maybe one night this week, thanks for ALLyou wonderful people's input

Hello adrian Now This Machine was built at the end of May 1961 ,The 7473 number is the Norton workshop Number And You (99SS) As A bore of 68mm and a Stroke of 82mm 600cc

I had a (99ss) Cafe racer And I thrashed the hell out of it And It just wanted more thrashing And I raced it too , well thats was back in the 70s My dad Sold It When I was At sea ?

Yours Anna J Dixon Happy thrashing?? Ps Theres not much diffrence between the top speed this 99SS and the speed of the 650ss ??? About 118 mph

I am gettinga little worried that this thread is beginning to wind itself up into a huge mess.

The photo that I attached is basically a standard 99 cylinder head which would have been fitted to most 88 and 99 engines from around late 1959 on.On theseheads there would have been a 2 into 1 carb manifold stuck on the back. They wouldalso have had the vertical carb manifold mounting studs slightly further apart. Up from 1.50" to 1.65". The heads also featured slightly larger inlet valves compared to pre 1959 engines..

At the bottom end, the standard engines would mostly have been equiped with coil ignition and the back of the crankcase stamped 99C to show this. However, you could have a Magneto fitted by the factory as an option. In which case there would only be 99 or nothing stamped.

Now the 99SS engine also used this old style of cylinder head but had a special adapter bolted onto it so that twin carbs could be fitted. These engines were fitted with the 650 barrels with wider pushrod tunnels to accomodate the fatter 650 style pushrods which were needed to cope with the stronger valve springs. I agree with Anna about the 650 engine having longer barrel sleeves and also believe these were used in the 99SS engines.

The 650 cylinder head wasalso available in 1961 but not fittedto the 99SS.(there were some exceptions) The two heads are quite different in the manner that carbs and exhausts were fitted.

As far as I know, the early factory built 99SS used the QR camshaft which was the forerunner of that used in the 650 engines. The chances are that the final batch of 99SS engines also used the proper 650 SS camshaft.

Genuine factory built 99SS engines were stamped at the back with 99SS. The other four digit number in this area is the batch number.eg 3575 would mean this was the 3575th engine made, probablyin a run of around 10,000 units, which might have included other models.

At the front of the crankcase, top left there should be the5(but possibly6) figure engine number. The NOC Bike Database shows 99SS numbers beginningat 96000 up to around 98200 but there are likely to be others either side.Possibly in the same area will be the number 14 to denote an engine for the 99model.

Some people claim that the very last batch of 99SS engine made, used 650 crankcases and cylinder heads. Can anyone confirm this?

Previously wrote:

I am gettinga little worried that this thread is beginning to wind itself up into a huge mess.

The photo that I attached is basically a standard 99 cylinder head which would have been fitted to most 88 and 99 engines from around late 1959 on.On theseheads there would have been a 2 into 1 carb manifold stuck on the back. They wouldalso have had the vertical carb manifold mounting studs slightly further apart. Up from 1.50" to 1.65". The heads also featured slightly larger inlet valves compared to pre 1959 engines..

At the bottom end, the standard engines would mostly have been equiped with coil ignition and the back of the crankcase stamped 99C to show this. However, you could have a Magneto fitted by the factory as an option. In which case there would only be 99 or nothing stamped.

Now the 99SS engine also used this old style of cylinder head but had a special adapter bolted onto it so that twin carbs could be fitted. These engines were fitted with the 650 barrels with wider pushrod tunnels to accomodate the fatter 650 style pushrods which were needed to cope with the stronger valve springs. I agree with Anna about the 650 engine having longer barrel sleeves and also believe these were used in the 99SS engines.

The 650 cylinder head wasalso available in 1961 but not fittedto the 99SS.(there were some exceptions) The two heads are quite different in the manner that carbs and exhausts were fitted.

As far as I know, the early factory built 99SS used the QR camshaft which was the forerunner of that used in the 650 engines. The chances are that the final batch of 99SS engines also used the proper 650 SS camshaft.

Genuine factory built 99SS engines were stamped at the back with 99SS. The other four digit number in this area is the batch number.eg 3575 would mean this was the 3575th engine made, probablyin a run of around 10,000 units, which might have included other models.

At the front of the crankcase, top left there should be the5(but possibly6) figure engine number. The NOC Bike Database shows 99SS numbers beginningat 96000 up to around 98200 but there are likely to be others either side.Possibly in the same area will be the number 14 to denote an engine for the 99model.

Some people claim that the very last batch of 99SS engine made, used 650 crankcases and cylinder heads. Can anyone confirm this?

Previously wrote:

Previously wrote:

I am gettinga little worried that this thread is beginning to wind itself up into a huge mess.

The photo that I attached is basically a standard 99 cylinder head which would have been fitted to most 88 and 99 engines from around late 1959 on.On theseheads there would have been a 2 into 1 carb manifold stuck on the back. They wouldalso have had the vertical carb manifold mounting studs slightly further apart. Up from 1.50" to 1.65". The heads also featured slightly larger inlet valves compared to pre 1959 engines..

At the bottom end, the standard engines would mostly have been equiped with coil ignition and the back of the crankcase stamped 99C to show this. However, you could have a Magneto fitted by the factory as an option. In which case there would only be 99 or nothing stamped.

Now the 99SS engine also used this old style of cylinder head but had a special adapter bolted onto it so that twin carbs could be fitted. These engines were fitted with the 650 barrels with wider pushrod tunnels to accomodate the fatter 650 style pushrods which were needed to cope with the stronger valve springs. I agree with Anna about the 650 engine having longer barrel sleeves and also believe these were used in the 99SS engines.

The 650 cylinder head wasalso available in 1961 but not fittedto the 99SS.(there were some exceptions) The two heads are quite different in the manner that carbs and exhausts were fitted.

As far as I know, the early factory built 99SS used the QR camshaft which was the forerunner of that used in the 650 engines. The chances are that the final batch of 99SS engines also used the proper 650 SS camshaft.

Genuine factory built 99SS engines were stamped at the back with 99SS. The other four digit number in this area is the batch number.eg 3575 would mean this was the 3575th engine made, probablyin a run of around 10,000 units, which might have included other models.

At the front of the crankcase, top left there should be the5(but possibly6) figure engine number. The NOC Bike Database shows 99SS numbers beginningat 96000 up to around 98200 but there are likely to be others either side.Possibly in the same area will be the number 14 to denote an engine for the 99model.

Some people claim that the very last batch of 99SS engine made, used 650 crankcases and cylinder heads. Can anyone confirm this?

Hi, I am very hesitant to add anything further to this thread but as Phil has asked a specific question.

I have posted, in this thread, a picture of my engine Web-Pic-1, from the factory records, NOC; the 99SS machine was despatched to the dealer on the 7th June 1961. An early 99SS engine?

If the bulge in the crankcase is a true indicator, this point again is in this tread, my engine has a 650cc crankcase, the head type can also be easily identified, this point also in this tread, I have a very full photographic record of the rebuild.

The camshaft is as 650cc, timing confirmed 50/74/82/42, cam followers are flat faced and pushrods are barrel shape and correct length as 650cc.

This is first hand knowledge not hearsay or conjecture.

If this tread will stand one more question, How does an engine with a 89mm stroke use the same barrel as an engine with a 82mm stroke? The stumbling block in my mind to suggestions so far is the fact the two engines use the same length pushrod, indicating that the crankcase to head spacing is the same.

Ron C.

hello ron first the 650 manxman was built from November the 7th 1960 ,and the 99ss was buitl from April 1961 using the 650 parts like crankcases camshaft and barrel and taps and pushrods but the cylinder head was the old patent with twin manifold fitted for two carbs so the 650 came first ,and the 650 as shorter conrods and bigger journal and 3.5 mm longer bottom spigot on the bottom of the barrel but you do not notice It ? Yours Anna J Dixon

Thanks everyone for a most interesting thread for me as I am at present rebuilding engine no. 14/87947. This has the pre downdraught SS head and camshaft T2219 QR. I think this fits with the chronology outlined in the thread. I think there must be two cylinder head castings used in this period as I have one fitted to the engine marked 22707 I and a spare marked 22707 and inverted Y. Also I wonder if anyone can identify the pistons. They are +30 and marked AE AM413 56H 16606 and have solid skirts. I can't find these numbers listed anywhere. I assume these were fitted when the engine was last rebuilt. (A long time ago!) I would like to know the compression ratio before I put everything together and can measure it. I attach a photo of one of the pistons.

Cheers

Alan

Previously wrote:

Thanks everyone for a most interesting thread for me as I am at present rebuilding engine no. 14/87947. This has the pre downdraught SS head and camshaft T2219 QR. I think this fits with the chronology outlined in the thread. I think there must be two cylinder head castings used in this period as I have one fitted to the engine marked 22707 I and a spare marked 22707 and inverted Y. Also I wonder if anyone can identify the pistons. They are +30 and marked AE AM413 56H 16606 and have solid skirts. I can't find these numbers listed anywhere. I assume these were fitted when the engine was last rebuilt. (A long time ago!) I would like to know the compression ratio before I put everything together and can measure it. I attach a photo of one of the pistons.

Cheers

Alan

hello Alan Arr Yes the Camshaft T2219 its SS and the piston are Hepalite A E stands for Auto Engineering Bradford yorkshire these are re-placement piston the orginal pistons where BHB 22512 LH and 22513 RH Hope this help anna j dixon

Previously wrote:

Hello, I am very interested in the late fifties and early sixties Norton Dominator. I read through the thread and thought I could add a bit.

I have a large collection of bikes and bits from this era. Bikes: The third 650 Norton built with engine no.2. 1962 650ss still on standard bore. 62' 88ss still on standard bore. 62' "Daytona 88" works racing bike with Domiracer bucket-tappet valvetrain. 64' 650ss. Relevant bits: Late fifties alternator model 99 cylinder barrel, collection of Dominator pistons in various oversizes including wellworthy, Hepolite AE powermax and Nomad.

I looked at all the cylinders I have for these bikes, about a dozen of them. I measured the thickness of the cylinder flange which holds the cylinder to the crankcase and it was the same on all cylinders around 12.5mm. The length of the cylinder sleeve down into the case from the cylinder base was the same on all of them, the model 99 cylinder does not have the notches cut into the sleeves for connecting rod clearance. The 650 cylinders have casting #22710 on the back of the base flange, the 88 and 99 cylinders do not.

From the bottom surface of the base flange to the top deck of the cylinders the 99 and 650 were the same. I measured nine different 68mm bore cylinders dating from the alternator model 99 with no rod-notches through Norton Manxman and mid-sixties 650ss cylinders and they all fell between 4.540"-4.75" in height. This was with a vernier caliper and I tried not to get old gasket and sealer material in the way. I used to work as a machinist and I am sure that a few thousandths of the difference in my measurements was due to the handling of the tool and dirt and debris, but I am sure that the factory fully intended all these cylinders to have the same "deck height".

I am thinking the different cylinder part numbers between early 650 and late model 99 machines was to insure that old factory and dealer stocks of model 99 cylinders were not put on the new 650, which would result in the rods hitting the non-notched cylinder bottoms and resulting in a catastrophic engine failure very quickly!

The 1964 Norton parts book lists the same cylinder for 650 and 99 engines!

"Norton publication p106, the 61'-63' owners manual says "It should be understood that the pistons were not altered but that all cylinder heads on 1960 and later engines give a higher ratio by approximately 1."

It says also:

"The original Daytona camshaft is fitted to every model 99 and all models 88 from 1956. Quietening ramps were added to this on all model 1959 and later models. From 1960 onward the same camshaft was used but with flat base tappets. In 1961 a camshaft giving slightly more lift was introduced on the 650 c.c. machines for export. Thiis is not fitted to all S.S. models along with tubular pushrods and special valve springs. It is also fitted to 650 c.c. Standard and deLuxe models."

An acquaintance of mine has two of the Daytona 88 works twins with wideline frames built in the 1950's to race at Daytona beach in Florida. These bikes were some of the first Dominators to have twin carburettors on them. He says that yes, the early bikes had a twin manifold with closer stud spacing than the later bikes with special equipment and the SS bikes.

Engine shop numbers: These were started over for each new engine. When the first model 99 engine was built for 1956 it started again, the model 88 engine shop numbers were already quite high this year. My early 650 Manxman with engine shop #2 on it was installed in the third production bike, I don't know if they started with zero or 1, or if they kept them in order as they dropped them in chassis, I doubt it. The newest 650 Manxman engine I have has engine shop# 343 on it, so that many 650cc engines and bikes were built by that point in time, probably at least a few hundred of them being the blue American speck Manxman bikes. These blue 650cc bikes are well-known in the USA and are not too rare, I am sure I know of a few dozen and could dig up another dozen if I tried. The 88ss and 99ss bikes are almost never seen in the USA at all, I am sure they must be the rarest Norton Dominator aside from the works racers.

The Manxman 650 was being built in late 1960 with it's new downdraught head and ugraded valvetrain. I am betting that as soon as stocks of old parts were used up, Norton put the 650 crankcases, cylinders and other parts into the 88 and 99, and the 88ss and 99ss, which were produced After the 650, surely had a lot of 650 parts in them.

My old friend Heinz Kegler, who worked in Norton's experimental department from the late fifties through the closing of Bracebridge Street, talked about how the American export market was very important. Berliner Corporation was the U.S. Norton distributor and they handled and sold most of Norton's production through the sixties, I heard figures that up to 80% of some of Norton's production was sent to the U.S.A. market in some years. Berliner was heavily into influencing what Norton produced all through the sixties, and they wanted bigger and faster bikes to compete with the Triumph and BSAs big dual carburetted twins.

The USA sucked up all the early 650 and 750 Norton twins. No one in the USA wanted a model 88 or 99 once the bigger twins were here in 61' and 62'. Some model 88 twins were sold here to make them legal for racing. Some 88s and 99s were brought over by American servicemen or they crept over from Canada etc..

After Bracebridge Street was shut down and Norton production moved to the AMC works, it is amazing that the 88ss and 650ss were kept in production at all. The 500-650cc slimline Norton Dominator was a high-point in Norton street bikes. They did everything well and some things better than those Nortons before and after them. They were very low production, and were produced at the time when British motorcycles were at their most refined and in their best era for performance and style, before corporate greed and competition from other countries started the industry on it's fall.

Someday when things are sorted out and fall into place, the Bracebridge street performance and SS Dominators of the late fifties and early sixties will be put at the top of the heap.....

Benjamin Gradler previously wrote on Monday November 29th at 17.09hrs:

>....................................Someday when things are sorted out and fall into place, the Bracebridge street performance and SS Dominators of the late fifties and early sixties will be put at the top of the heap.....<

Benjamin,

Thank you very much for spending so much time measuring; researching and reporting on this issue. I have thoroughly enjoyed reading your message.

While I appreciate all the work you have done, I am especially impressed at the amount of typing involved (because that is something that always takes me ages, also the part I enjoy the least)!

Forgive me; but I think you have made one error, where you said: â......... is not fitted to all S.S. models along with tubular pushrods and special valve springs. It is also fitted to 650 c.c. Standard and deLuxe models."

Which should read: is fitted to all SS models?

Thatâs small change really and I did not mean it as derogatory.

Shame we don't have the facility to edit our own posts for a few hours, as other forums have.

Please accept my compliments on your collection.

By the way, are you the âBenny Gradlerâ of Erie Motorcycles Sales and Service, or was that your father?

Paul

Yep, got a typo in there, you are right. I have to learn to proof-read . My father did have Erie Motorcycle sales in the late fifties and early sixties. He raced and sold the Matchless bikes, and brain-washed me as a child to be addicted to British motorcycles for life.....

Previously wrote:

Previously wrote:

Hello, I am very interested in the late fifties and early sixties Norton Dominator. I read through the thread and thought I could add a bit.

I have a large collection of bikes and bits from this era. Bikes: The third 650 Norton built with engine no.2. 1962 650ss still on standard bore. 62' 88ss still on standard bore. 62' "Daytona 88" works racing bike with Domiracer bucket-tappet valvetrain. 64' 650ss. Relevant bits: Late fifties alternator model 99 cylinder barrel, collection of Dominator pistons in various oversizes including wellworthy, Hepolite AE powermax and Nomad.

I looked at all the cylinders I have for these bikes, about a dozen of them. I measured the thickness of the cylinder flange which holds the cylinder to the crankcase and it was the same on all cylinders around 12.5mm. The length of the cylinder sleeve down into the case from the cylinder base was the same on all of them, the model 99 cylinder does not have the notches cut into the sleeves for connecting rod clearance. The 650 cylinders have casting #22710 on the back of the base flange, the 88 and 99 cylinders do not.

From the bottom surface of the base flange to the top deck of the cylinders the 99 and 650 were the same. I measured nine different 68mm bore cylinders dating from the alternator model 99 with no rod-notches through Norton Manxman and mid-sixties 650ss cylinders and they all fell between 4.540"-4.75" in height. This was with a vernier caliper and I tried not to get old gasket and sealer material in the way. I used to work as a machinist and I am sure that a few thousandths of the difference in my measurements was due to the handling of the tool and dirt and debris, but I am sure that the factory fully intended all these cylinders to have the same "deck height".

I am thinking the different cylinder part numbers between early 650 and late model 99 machines was to insure that old factory and dealer stocks of model 99 cylinders were not put on the new 650, which would result in the rods hitting the non-notched cylinder bottoms and resulting in a catastrophic engine failure very quickly!

The 1964 Norton parts book lists the same cylinder for 650 and 99 engines!

"Norton publication p106, the 61'-63' owners manual says "It should be understood that the pistons were not altered but that all cylinder heads on 1960 and later engines give a higher ratio by approximately 1."

It says also:

"The original Daytona camshaft is fitted to every model 99 and all models 88 from 1956. Quietening ramps were added to this on all model 1959 and later models. From 1960 onward the same camshaft was used but with flat base tappets. In 1961 a camshaft giving slightly more lift was introduced on the 650 c.c. machines for export. Thiis is not fitted to all S.S. models along with tubular pushrods and special valve springs. It is also fitted to 650 c.c. Standard and deLuxe models."

An acquaintance of mine has two of the Daytona 88 works twins with wideline frames built in the 1950's to race at Daytona beach in Florida. These bikes were some of the first Dominators to have twin carburettors on them. He says that yes, the early bikes had a twin manifold with closer stud spacing than the later bikes with special equipment and the SS bikes.

Engine shop numbers: These were started over for each new engine. When the first model 99 engine was built for 1956 it started again, the model 88 engine shop numbers were already quite high this year. My early 650 Manxman with engine shop #2 on it was installed in the third production bike, I don't know if they started with zero or 1, or if they kept them in order as they dropped them in chassis, I doubt it. The newest 650 Manxman engine I have has engine shop# 343 on it, so that many 650cc engines and bikes were built by that point in time, probably at least a few hundred of them being the blue American speck Manxman bikes. These blue 650cc bikes are well-known in the USA and are not too rare, I am sure I know of a few dozen and could dig up another dozen if I tried. The 88ss and 99ss bikes are almost never seen in the USA at all, I am sure they must be the rarest Norton Dominator aside from the works racers.

The Manxman 650 was being built in late 1960 with it's new downdraught head and ugraded valvetrain. I am betting that as soon as stocks of old parts were used up, Norton put the 650 crankcases, cylinders and other parts into the 88 and 99, and the 88ss and 99ss, which were produced After the 650, surely had a lot of 650 parts in them.

My old friend Heinz Kegler, who worked in Norton's experimental department from the late fifties through the closing of Bracebridge Street, talked about how the American export market was very important. Berliner Corporation was the U.S. Norton distributor and they handled and sold most of Norton's production through the sixties, I heard figures that up to 80% of some of Norton's production was sent to the U.S.A. market in some years. Berliner was heavily into influencing what Norton produced all through the sixties, and they wanted bigger and faster bikes to compete with the Triumph and BSAs big dual carburetted twins.

The USA sucked up all the early 650 and 750 Norton twins. No one in the USA wanted a model 88 or 99 once the bigger twins were here in 61' and 62'. Some model 88 twins were sold here to make them legal for racing. Some 88s and 99s were brought over by American servicemen or they crept over from Canada etc..

After Bracebridge Street was shut down and Norton production moved to the AMC works, it is amazing that the 88ss and 650ss were kept in production at all. The 500-650cc slimline Norton Dominator was a high-point in Norton street bikes. They did everything well and some things better than those Nortons before and after them. They were very low production, and were produced at the time when British motorcycles were at their most refined and in their best era for performance and style, before corporate greed and competition from other countries started the industry on it's fall.

Someday when things are sorted out and fall into place, the Bracebridge street performance and SS Dominators of the late fifties and early sixties will be put at the top of the heap.....

Benjamin,

thanks for the technical information.

I have Norton # 93736 , Manxman shop # 70.

I take issue with your statement that they are " well known and not too rare".

i have only seen one other , maybe because you have a dozen or so tucked away? or know of a couple dozen others , also tucked away?

they belong on the road.

Steven Phelps wrote :"Benjamin, thanks for the technical information. I have Norton # 93736 , Manxman shop # 70. I take issue with your statement that they are " well known and not too rare". i have only seen one other , maybe because you have a dozen or so tucked away? or know of a couple dozen others , also tucked away? they belong on the road."

What student of Norton does not know about the U.S. specification blue 650 Manxman? It is a famous bike.

How many miles are you putting on yours each week? Glad to hear it.

I am not sure what other point you are making, you are saying because YOU have seen only one other Norton Manxman besides yours it means something because?

Of the top of my head, there is a guy in New York State that has two, there are a two others here in Pennsylvania, I have one, I sold one to a guy in Chicago who is riding it, I know a fellow in Wisconsin who has one, I know of two in Ohio. The old Norton dealer in Atlanta has one as does another old Norton dealer in Colorado. There is one in Massachusetts. I have five extra Manxman engines or case sets and have passed up others. A few have been exported back to England. I have letters of correspondence with more Manxman owners I could dig up that are not at the top of my head. Most of them need restored or other work. I love to talk about them, If you need to get in touch with other Manxman owners or parts let me know in a PM or email so we do not clog up the forum so much.

If you talk about Norton Dominators imported into the United States in the 1960's, the thousands of Norton Atlas bikes are the most common, that is a sure thing, including the various Atlas engined scramblers that are laying all over the place. The Atlas scramblers seem to come up for sale even more often than featherbed 750s for some reason. I know if I had one I would get rid of it...

After that there is not much else besides the maybe four-five hundred 650cc Nortons imported into the U.S. a few hundred of them the blue 61'-62' bikes and just as many 650ss bikes from 62' through 67'.

Again, there are very few slimline model 88 and model 99 bikes in the USA because there was simply no reason for them to be here next to the Manxman and Atlas, and they are the rarest slimline Nortons.

Now over in England things might be just the opposite. When the featherbed Dominator came out it's first year it was export-only, the model 99 was export only for it's first year in 1956, thus wideline dommies are found in the States about as often as 650ss bikes. Most all the 650 Manxman production went to North America and also most of the Atlas, Commando and Scrambler production.

What did that leave in England? While all the newest and fastest Norton twins were being exported, the English home market got all the docile singles, model 88 and model 99 production, and they got most of the 88ss, 99ss and 650ss bikes too because who in the States would buy one with the Manxman sitting next to them in 61' or the Atlas next to them in 62' on?

Previously wrote:

Steven Phelps wrote :"Benjamin, thanks for the technical information. I have Norton # 93736 , Manxman shop # 70. I take issue with your statement that they are " well known and not too rare". i have only seen one other , maybe because you have a dozen or so tucked away? or know of a couple dozen others , also tucked away? they belong on the road."

What student of Norton does not know about the U.S. specification blue 650 Manxman? It is a famous bike.

How many miles are you putting on yours each week? Glad to hear it.

I am not sure what other point you are making, you are saying because YOU have seen only one other Norton Manxman besides yours it means something because?

Of the top of my head, there is a guy in New York State that has two, there are a two others here in Pennsylvania, I have one, I sold one to a guy in Chicago who is riding it, I know a fellow in Wisconsin who has one, I know of two in Ohio. The old Norton dealer in Atlanta has one as does another old Norton dealer in Colorado. There is one in Massachusetts. I have five extra Manxman engines or case sets and have passed up others. A few have been exported back to England. I have letters of correspondence with more Manxman owners I could dig up that are not at the top of my head. Most of them need restored or other work. I love to talk about them, If you need to get in touch with other Manxman owners or parts let me know in a PM or email so we do not clog up the forum so much.

If you talk about Norton Dominators imported into the United States in the 1960's, the thousands of Norton Atlas bikes are the most common, that is a sure thing, including the various Atlas engined scramblers that are laying all over the place. The Atlas scramblers seem to come up for sale even more often than featherbed 750s for some reason. I know if I had one I would get rid of it...

After that there is not much else besides the maybe four-five hundred 650cc Nortons imported into the U.S. a few hundred of them the blue 61'-62' bikes and just as many 650ss bikes from 62' through 67'.

Again, there are very few slimline model 88 and model 99 bikes in the USA because there was simply no reason for them to be here next to the Manxman and Atlas, and they are the rarest slimline Nortons.

Now over in England things might be just the opposite. When the featherbed Dominator came out it's first year it was export-only, the model 99 was export only for it's first year in 1956, thus wideline dommies are found in the States about as often as 650ss bikes. Most all the 650 Manxman production went to North America and also most of the Atlas, Commando and Scrambler production.

What did that leave in England? While all the newest and fastest Norton twins were being exported, the English home market got all the docile singles, model 88 and model 99 production, and they got most of the 88ss, 99ss and 650ss bikes too because who in the States would buy one with the Manxman sitting next to them in 61' or the Atlas next to them in 62' on?

hello ben talking about the Norton Manxman we have now found out there was some 890 machine sent too the USA that before the 650ss it came out in October 61 ? I own num ber 288 built at the end of december 1960 sent to the USA on the 13th of january 61, alongwith 350 machines ? Now I am looking for a pair of mufflers for it , Can you Help, I have a Manxman 650 Parts Manual dated december 1960

the parts numbers are 23174RH and 23437LH

yours anna j dixon

Previously wrote:

Steven Phelps wrote :"Benjamin, thanks for the technical information. I have Norton # 93736 , Manxman shop # 70. I take issue with your statement that they are " well known and not too rare". i have only seen one other , maybe because you have a dozen or so tucked away? or know of a couple dozen others , also tucked away? they belong on the road."

What student of Norton does not know about the U.S. specification blue 650 Manxman? It is a famous bike.

How many miles are you putting on yours each week? Glad to hear it.

100 miles or more , every week. i met a fellow once who told me he had 38 Nortons, that usually means 37 are not on the road. it becomes a very personal issue, the conflict between preserving and hoarding. now that ihave retired i hope to have all theworn outbikes i have collected, assembled and in the hands of someone to ride and enjoy. thats my goal. sorry to "clog up the forum so much"

I am not sure what other point you are making, you are saying because YOU have seen only one other Norton Manxman besides yours it means something because?

Of the top of my head, there is a guy in New York State that has two, there are a two others here in Pennsylvania, I have one, I sold one to a guy in Chicago who is riding it, I know a fellow in Wisconsin who has one, I know of two in Ohio. The old Norton dealer in Atlanta has one as does another old Norton dealer in Colorado. There is one in Massachusetts. I have five extra Manxman engines or case sets and have passed up others. A few have been exported back to England. I have letters of correspondence with more Manxman owners I could dig up that are not at the top of my head. Most of them need restored or other work. I love to talk about them, If you need to get in touch with other Manxman owners or parts let me know in a PM or email so we do not clog up the forum so much.

If you talk about Norton Dominators imported into the United States in the 1960's, the thousands of Norton Atlas bikes are the most common, that is a sure thing, including the various Atlas engined scramblers that are laying all over the place. The Atlas scramblers seem to come up for sale even more often than featherbed 750s for some reason. I know if I had one I would get rid of it...

After that there is not much else besides the maybe four-five hundred 650cc Nortons imported into the U.S. a few hundred of them the blue 61'-62' bikes and just as many 650ss bikes from 62' through 67'.

Again, there are very few slimline model 88 and model 99 bikes in the USA because there was simply no reason for them to be here next to the Manxman and Atlas, and they are the rarest slimline Nortons.

Now over in England things might be just the opposite. When the featherbed Dominator came out it's first year it was export-only, the model 99 was export only for it's first year in 1956, thus wideline dommies are found in the States about as often as 650ss bikes. Most all the 650 Manxman production went to North America and also most of the Atlas, Commando and Scrambler production.

What did that leave in England? While all the newest and fastest Norton twins were being exported, the English home market got all the docile singles, model 88 and model 99 production, and they got most of the 88ss, 99ss and 650ss bikes too because who in the States would buy one with the Manxman sitting next to them in 61' or the Atlas next to them in 62' on?

Previously wrote:

Previously wrote:

Steven Phelps wrote : sorry to "clog up the forum so much"

I meant I am done talking about the Norton Manxman here. I don't want to hijack the model 99 thread and turn it into a Manxman thread, it is cluttered enough. Also note that when you do reply to a posting, you can delete all of it except for the part you are addressing so there are not fifty copies of the same thing in a thread.

Previously wrote:

Back in 1965 John Hudson referred to my own 1959 '99' as a "99 Special" because it had quite a few of the optional factory extras, like large inlet valves, twin carbs, HC pistons, chrome mudguards, full rear chainguard etc. I wrote to him with many technical queries during its first strip and rebuild. His own view was that twin carbs weren't worth the bother but small-bore siamese pipes with an "SS silencer" gave a performance increase on the 99. If your engine is a "14P" (1959 Model 99) maybe they labelled it because of the ex-works mods? Cheers, Lionel

Hi, back in 1961 I bought a 600 SS from Hooleys in Nottingham, at that time there was quite a lot of experimenting going on, one was to upgrade the piston to 8. 3/4 to 1compression, another as you have said was to put siamese pipes on, twin carbs were not fitted as standard at that time, there were many conversions brought out but try and get one now is almost impossible, many who have carburettor problems on Amal Monoblocs tend to over tighten the nuts holding the carb on to the engine, this has a tendency to distort the facing and that allows air to seep inbetween the facing, that causes the engine to run lumpy or to keep cutting out, no alteration of the mixture screw will cure this until the facing is leveled again, so now is my question to anyone reading this, can anyone tell me where I can get the twin carb conversion from.

Previously wrote:

hello do you meen 99c ,I have not heard of a 99s ,but have heard off the 99ss built from april1961 to sep1963 this engine shares the camshaft and pushrods and followers from the Norton Manxman 650

Hi, sorry to disagree with you but the 88-99 SS was first sold on the 1st of January 1958, it was bought by a consortium, I know as I have it and at present am restoring it back to its original condition,

Some late 99 motors had the 650 cases with the bulge.

late 99 motors were fitted with 650 cases with a bulge, did Norton actually sell any 650 DL bikes, i never saw or heard of one,i would think they would be fitted with a 99DL head and manifold to match the slotted side panel tickler set up.My 99 has 650 ss pistons which work well.

Previously wrote:

Previously wrote:

hello do you meen 99c ,I have not heard of a 99s ,but have heard off the 99ss built from april1961 to sep1963 this engine shares the camshaft and pushrods and followers from the Norton Manxman 650

Hi, sorry to disagree with you but the 88-99 SS was first sold on the 1st of January 1958, it was bought by a consortium, I know as I have it and at present am restoring it back to its original condition,

Hello Patrica Well You have to disagree with Norton Factory records, The first 600cc 99sports special was built in March 1961 colour's where Norton grey and dove grey the machine you are referring to where know as the Clubman fitted with twin Carburetters Colours where, post office red or metalescent blue

I think most people dont realise that Norton were really small fry compared to other manufacturers and were prepared to fit all sorts of special parts and finishes to get a sale. When i wanted to restore a 99DL i researched to find what the colours should be,Neville Hinton insisted that it should be Blue/Dove although ieventuallyfound outfor a fact it was made Red/dove,soon i discovered that initially you could have a 99DL in a wide range of colours but that was such a headache that the factory standardised with the 88 in RED/Dove and the 99 in Blue/Dove, I bet you could have had a chrome front mudgaurd and chaincases on a DL.

Hi folks. I've been a member since 2007 but this is my first post so be gentle....

I've been reading this thread with interest. My own Dommie - Eng. 79126, N14 - was first registered in Sept 1958 and is denoted as a '99 Special' on the old log book. It is Post Office Red, with chrome guards and handrails, has the larger inlet valves and is twin carb - 376/67's. It is coil ignition. Basically it appears to have most of the 'optional extras' for the '59 model. I struggle to get an even tickover on the carbs which I presume are the 50+ year old originals, and I note the point about ensuring the mating surfaces are flat which I have spent a considerable amount of time ensuring that they are. I guess the carbs are just knackered.

Anyway, here's my query... I had an idea to change it to single carb, and bought the manifold listed in my parts book - Pt. No. 18242 to do this. However the vertical stud spacings (ie on the head) are farther apart than on this manifold. Does anyone know if a manifold is available to convert this head to single carb? When I asked Mick Hemmings he suggested scouring the autojumbles, which I get very little opportunity to do.