norton dominator

I have alloy rims on the Atlas,   Doubt they were an option but at least they don't go rusty.  The replacement rods are only availiable from the aftermarket and are a bit pricey and may need to be sized to suit pistons.  

I don't think many replace rods unless racing

What engine is it? 

If using the old rods  they need to be checked for ovality in the big ends and any nicks on the rod faces where they may have knocked the cases need polishing out.  There are other treatments possible ,crack testing and shot blasting , Would be interesting to find out if these are of any real value . as our  old rods are  now  very old!.

Check the parts list for that year. The 62 88 had factory option listed for alloy rims. In that era I would guess Dunlop alloy rims.  Borranni seemed to be much later.

I don't know about the 60's (I was too busy raising a family), but back in the 50's Norton would add any extras a customer required (at a price!) So, alloy rims were probably an option.

Alloy rims was a common upgrade in the sixties. Main reason was to minimize unsprung weight. And of course for looks. Since they are serrated there is no need for security bolts, making it easier to fit tyres. Did it myself back in -67 on my -60 99. So if you want a period look, alloy rims are perfectly ok.

The 88 and the 99 has a small end bushing while the 650 and Atlas don't. So my long time 650 project needed new conrods due to small end wear.

Atlas and 650 rods can have their small ends bushed back to a standard size.  A cheaper option to buying new rods.

The 1960 Birmingham factory parts list and suplimentary  list  for that year does NOT list alloy rims as an option. The usual thing was that owners replaced the steel rims with alloy after a crash or when they got fed up with rust. Our SH  Atlas fake Dunstall came with  Boranni Record  very  aged and weathered  rims taken from an old possibly pre-war race  Norton  and supplied by Alf Hagon. Somewhere between a WM1 and 2 ,  ok for a 300x 19 front  but useless for an Atlas rear  tyre. I laced in a new Acront  wm3 a few years ago.  The Factory lists do make interesting reading with many optional items.

hello aloy rims are in original parts catalog from 1963

as optional parts

My perception is that in the 1950's bikes were  ride to work transport  with very little spare cash for  bling . By the mid 1960's  cars took over that role and bikes became  more playthings  and  fripery like alloy rims and  extra chrome  became more common. Seems like sometime after 1960 Norton  responded to the trend and added rims to the list. I was surprised to read  that the Big valve 1960  88/99 heads could be ordered with even larger  inlet valve seats which must have been bigger than the std 650SS.

I can thoroughly recommend David Burton Engineering, Holly Road, Red Marsh Industrial Estate, Thornton Cleveleys, Lancs. FY5 4HH. Tel:0125 3868111.

David made a fantastic job on my 650SS barrels, it was worth the drive down from Orkney to his workshop!

Kevin

My model 50 comes with alloys, and surprisingly many stock photos show them similarly shod. Must be some logic behind fitting them, and as said previously cash for “bling” was not high on the agenda then.  Supply and demand, lack of stock of steel rims, Chrome shortages? I have no idea but there does seem to be more fitted on turn of the decade bikes, and as by my example not for sporting purpose.

cold in the garage....

Jon

Very much agree early bikes were "transportation" but with the mini, bikes slowly became "recreation".

Looking through the books I find the early heads are 1.3"intake/1.3" exhaust.

Later pre S650/136 heads are offered as optional big valve. Yet the only documented parts offered are the 1.4"intake and 1.3"exhaust. The seats for these R12-2/136 and 88SS/136 heads are 1.5" and continue to desaxe 750&850 heads. So far, I only find evidence of factory/production 1.5" valves in 750/850 heads. I have seen aftermarket hot rod 1.5"valve upgrades(sic) to small NHT engine heads. 

What are they thinking 10-12000 rpm 88SS on an early crank?  SS cam?  PW3?

Tongue firmly in cheek - Perhaps the factory knew that so many model 50's would end up as Tritons, they sent them out part dressed?

Heres to a good next year 

George. 

In the UK, for most people, fuel economy was foremost in our minds. Flashy bike but good economy was perhaps more important than the other way round. And our roads were terrible!

I was looking for a part number in my 1950 Spare Parts List for singles and the three loose sheets fell out.   They list the alloy parts that were available through Francis Beart.   Surprisingly more than what I would have thought.  

Hi David.  My 1960  88and99  came as std  with the 1.3" and 1.4" valves which were the same size as the 650.  Perhaps the 1960 parts list  bigger seat option was intended for the earlier pre 60 heads.    Can't imagine that bigger valves would have been any use on the 88SS for road use.  My 250 has 40 mm in and 36 exhausts  and it would be a far better machine if  it had smaller valves and port.

It is certainly more difficult to get any useful data here in the US since we have so little bikes before Berliner started importing nortons.

Below is what I have found so far:

1955 K12/136   measures 1.5" intake seats    1-1/2" studs  I     D12/142    1.3" E   D12/143  1.3"

1959 50166   SUPS  K12/136     1-1/2" studs I    D2010  1.3" E   D2204  1.3"

1959 option big valve/dual carb 21325A  base=50166   SUPS  K12/136? I  17221   1.4" E  D2204   1.3"

1961 R12-2/136  88/99 early valve springs   I 17221  1.4" E D2204  1.3"

1961 88SS  61/62/99SS  SScam/late springs 88SS/136     1-5/8' studs I 17221  1.4" E D2204  1.3"

61 option 21325A  polished head 88/99  18542 manifold dual carbs  ? 21225 early cam or SS cam ? I 17221  1.4" E D2204  1.3"

S650/136   61-62 650  62-88SS SScam/late springs I 17221  1.4" E D2204  1.3"

I have most of these heads except the polished head. Any insite?

added: I hate how the forum text compiler toatally changes my text structure.

I have never seen inside a genuine 88SS,   Back in the late 60's,   I was running a  twin carb 88 with the splayed inlet manifold and a 650SS cam and carbs .  I was very taken with the 88SS with the downdraught carbs and the looks of the 650SS, I persuaded a contact  with a genuine 88SS to swop bikes for a comparison. I was very dissapointed as it seemed to have less go than my fake.and did not handle as well with clip on bars. I have read that the DD head did not actually give a performance boost and it was sales hype to sell more bikes.

I just put the head back on my 88SS. No idea of the valve sizes, but David Comeau tells me it is as 650SS. Interesting to speculate on why anyone bought an 88SS for the road, when the 650 version cost so little more. I suppose it was aimed at 500cc club  racing?

Small NHT are fairly rare here in the US. I am building a 122 engine in a 59 case as a 62-SS. I will first try the S650 head with stock 28.5mm ports and  28mm concentrics. This is without port liners which would normally increase the velocity. I may later try and make some port liners to see if it improves anything. Following that I would change the head to 88SS/136 which are stock 25mm ports. I will have to machine/fabricate a dual carb manifold which should not be to difficult.

After this is all tried I will proceed to a 650SS engine for trial.

The 88SS was popular for production races and endurance events .On occasions  it out performed the 650's and won  races.  A very well balanced package and less tiring to ride than  more vibratory  bigger bikes.