Norton 88 A civilized twin
For those of us who can remember back that far, the official coming-of-age celebration represented by the 21st birthday party can be a treasured occasion, an afterwards indistinct tale of excesses, of gifts, of well-wishing.
So what did Tony do with his luscious gift? Leap aboard and ride it far and wide? Pose at the milk bar? Plant a femme fatale upon the pillion to the envy of his mates? No. “I rode the bike for about 500 miles, and being accustomed to Japanese machinery was thoroughly unimpressed by the level of vibration as it shed parts down the road on every outing,” recalls Tony. “This included both mufflers, the headlamp and even the generator at one time. The source of this vibration was traced – many years later – to loose and even missing engine bolts.” So he pulled it apart and shoved the components in boxes, there to remain until 2016. Had it not been for the expertise and perseverance of Don Tonkin, McLaren Vale’s craftsman par excellence, the 88 may well still be in those boxes.
At this point, it’s worth a quick rundown on the Model 88 itself, beginning with the granddaddy of all the Norton parallel twins, the Model 7, which set fans talking when it made its public debut at the Earls Court Motorcycle Show in November 1948. The allnew engine which produced 29hp was the work of the celebrated engineer Bert Hopwood, who had a fair hand in the concepts of both the Triumph twin and the Ariel Square Four and would later be responsible for the BSA A10 twin. Most of the Model 7 running gear was sourced from existing Norton stock, mainly the single cylinder ES2, along with a beefed up Norton gearbox. That gearbox actually began life around 1931 as a Sturmey-Archer product, but when their production ceased, Norton picked up the design and had it produced for their use by Burman. The Hopwood design was actually Norton’s second attempt at a parallel twin, following an exercise in 1946 by Jack Moore. This prototype, which was also fitted into an ES2 frame with plunger rear suspension and two-way-damped Norton Roadholder forks, was similar to the Triumph, with two camshafts and two separate rocker boxes cast in light alloy. When Hopwood came on board at Norton in 1947, he expressed little interest in the Moore design and started with a clean sheet of paper. Like its British contemporaries, the new engine used a 360-degree crankshaft, with its inherent vibrations. This trait was not seen as a major issue in the fairly mild state of tune of the Model 7, but certainly became one as larger capacity versions came on stream, each producing more and more power. The vibration bugbear reached its nadir with the 750cc Atlas, and led directly to the Commando concept which isolated (not eliminated) the vibes via the Isolastic frame/engine mounting system. The original 497cc engine, with bore and stroke of 66mm x 72.mm, used cast iron for the head and block, with a single carburettor and the fairly ubiquitous Lucas magneto and dynamo. A combination of gears and chain drove the single camshaft at the front of the engine, and a fibre gear running off the camshaft in turn drove the dynamo. The built-up crankshaft, with a central cast iron flywheel, was supported by two main bearings; a ball race on the timing side and a roller race on the drive, which incorporated an outer oil seal. Exhaust ports were splayed to allow maximum cooling air to reach the area, the air then directed through the hotter areas of the engine. The Model 7 was a solid, if unremarkable machine, but in 1952 came a change that was to invoke the Norton twin with a completely new personality, although the Model 7 continued in production for a period. The ‘Featherbed’ frame that had graced the works Norton racers for two years appeared wrapped around the twin engine at the 1951 Earls Court Show, where it caused much excitement. The Model 88 Dominator had been born. However for the home market it was only a fleeting glimpse, as the 88 was originally listed for export only. The frame followed the same general layout as on the Manx, but was made from a lower grade Reynolds tubing, arc
welded rather than bronze welded, with the rear swinging arm pivoting on Silentbloc bushes. As on the Manx, the rear sub-frame was bolted on and controlled by Armstrong spring and damper units. Up front were new, shorter Roadholder forks modelled on the Manx jobs, with the steering crowns now running in ball bearings rather than cups and cones. The Model 88 tipped the scales a full 40 pounds (18kg) lighter than the Model 7. Like the Manx, the 3.5 gallon petrol tank on the 88 sat on rubber pads on the top tubes of the frame and was held in place by a strap which hinged from the front, behind the steering head. Naturally, few fittings or chassis components carried over from the Model 7. Under the dual seat that replaced the Model 7’s sprung saddle sat a tool tray, with the oil tank and battery below that, both of these sitting on a platform above the gearbox. Brakes remained at 7-inch but the front wheel was now 19 inch with a 3.25 section tyre. The Show model 88 had a black frame, but by the time the 88 went on sale in the UK, all metal parts including the frame were painted in a metallic grey. The petrol tank was chrome plated with grey panels with black and red striping, as were the wheel rims. This décor was not universally popular, at least with the British, so for 1953 a black and silver option was listed. The peashooter silencers used on the Model 7 gave way to a new elliptical shape, with the inlet at the bottom and the outlet at the top. These soon gained the nick-name of ‘pear-shaped’ silencers. For 1958, the Model 88 received an 8-inch front brake, an item it sorely needed, as stopping power, or lack of it, had been a universal criticism, but the major change in the twin’s design came the following year when a new light-alloy cylinder head was fitted, along with an Amal Monobloc carburettor to replace the old Amal 6 Type. The Featherbed frame finally became a one-piece unit, with the sub-frame welded in place rather than bolted on. The single-sided hubs were also scrapped in favour of cast alloy full-width hubs.
In its primary export market, the United States, the 88 sold well but there was a growing clamour for more power. Both Triumph and BSA had already answered this demand, with the 6T (Thunderbird) and A10 (Golden Flash) respectively. Norton’s answer was the Model 99, with the capacity stretched to 596cc (68mm bore x 82mm stroke), with a slightly larger 1 1/16” carburettor. However the Model 88 continued in production, as it would until 1966 (as the 88SS), with an increase in compression ratio to 7.8:1. Both models had their midriff tidied up, with a new oil tank on the right and a battery cabinet on the left. 1956 also marked the end for the venerable Norton ‘lay-down’ gearbox, with the casing revised and now manufactured by Norton’s owner AMC in London. Detail changes continued to be made to the 88 and 99 year by year, such as Girling rear units in 1957 with a Lucas RM15 alternator, coil ignition and distributor replacing the magneto in 1958.
In an exercise that generated a ton of publicity, former World Sidecar Champion Eric Oliver took a virtually standard Model 88, fitted a Watsonian Monaco sidecar, and finished an amazing tenth (with Mrs Pat Wise in the chair) in the 1958 Isle of Man Sidecar TT. As the new decade loomed, Norton embarked on a restyling adventure with the addition of a rear enclosure similar to Triumph’s unloved ‘Bathtub’, which was fitted to both the twins as a De Luxe version, but which only lasted two years in production. 1960 also saw the addition of what became known as the ‘Slim Line’ frame, with the top frame rails moved closer together, along with a different style petrol tank with cast metal badges. The 88 also received modified porting and slightly higher 8.0:1 pistons. The 88SS (Sports Special) came on steam for 1961, with twin carburettors, high performance cams, dual valve springs, a further lift in compression ratio and lighter pushrods, which pushed power up to 36hp at 7,000 rpm. To deal with the extra poke, stronger clutch springs were fitted. Optional extras on the 88SS included rear set footrests, a rev counter and single muffler, and a Siamesed exhaust system. The last of the standard Model 88s were built until the end of 1963, the 500 continuing only as the 88SS, which finally received 12 volt electrics in 1964. And after 14 years in production, the 88 came to an end late in 1966.
The resurrection
Don Tonkin’s restoration of Tony Morisset’s Model 88 is well-nigh flawless and typical of this master craftsman’s work and attention to detail. Don says there are actually two shades of the Norton Polychromatic Grey, and this is the lighter of the two, which he matched from the original colour on the inside of the tool case. The actual painting was done by Daniel Stone, and the plating by A Class Chrome in Adelaide. Being a 1955 model, Tony’s 88 still has the “laydown” Norton gearbox, with magneto ignition, and features the circular plastic tank badges introduced for that model year. The new-for-55 alloy cylinder head sits atop the iron block. The primary chain case is also the pressed steel type with the outer cover retained by a central fixing that also mounts the left side footrest.
The attention to detail carries through to the bespoke battery case made by Don from wood, which is hollow and contains a modern unit. Sitting unobtrusively under the seat on the side of the tool tray is the ignition kill switch, as there is no key for the magneto ignition. Despite its age, but perhaps because of its extended period of hibernation, the 88 retains the original Armstrong rear shock absorbers, which are one-size-fits-all and devoid of any springing or damping adjustment. The wheels were rebuilt with rims and spokes sourced from Central Wheel Components in UK.
This was no cosmetic restoration, as the old Norton, as well as being completely dismantled and suffering the inevitable ravages of life in a loft, was pretty tired to begin with. “The bike had a high mileage on it, as considerable wear in all engine components, bushes and even fork legs was evident,” says Tony. “The new seat, and the mufflers and header pipes, were purchased from Norvil in UK, and Burlen Fuel Systems, also in UK, supplied the correct Amal Monobloc carb, already jetted for the model. Instead of fitting a modern belt primary drive and clutch, we decided to rebuild the original Norton components. Friction material is modern “Surflex” rather than cork. The nylon-lined cables and correct-pattern levers make the clutch light and responsive. The option to convert to a belt drive at a later date is always available as these are an off-the-shelf conversion from Norvil. The mechanical Lucas voltage regulator was replaced with a 60volt solid state item from Groves in the UK. This is fitted inside the Lucas housing and wired to the original terminals.” When I photographed the bike, the beautifully rebuilt Norton had just 8 miles on the odometer, but this will change, because Tony had a group of very keen mates in the McLaren Vale region, all of whom need little prompting to get out and enjoy the wonder roads in the area. And one thing’s for sure, thanks largely to Don Tonkin, the Model 88 is in far better fettle than it was when Tony rattled to a halt and parked it up all those years ago.