AJS 1933 model 33-7 474cc 1 cyl OHC 3511

AJS 1933 model 33-7 “Trophy” Camshaft Competition Model 474 cc OHC single frame # 7/573 engine # 33/7 522

In 1931, in the middle of the economic depression, The Matchless Company takes over AJS Motorcycles and moves production from Wolverhampton to London. AJS machines keep their identity for some years, but from halfway the thirties rationalization is the keyword and Matchless and AJS models become almost identical, even to the engine numbering system, in which first the year and then the model code are shown. The 1933 catalogue shows two OHC models, the 33-7 3.46 HP OHC Trophy and the 4.95 HP OHC trophy, priced at £65 and £70 respectively.
The 1933 Camshaft Trophy models are broadly similar in engine design to the Wolverhampton built machines, the most obvious visual difference being that the magneto is now sited behind rather than in front of the engine. There are also changes to the lubrication of the cambox, and a new frame is employed. The models are offered in both “Competition” and “Race” trim. The racing models have no kick starter and a low exhaust position.
The machine we present here has been flat tracked in Canada and the engine bore and stroke dimensions had been changed, resulting in a cubic capacity of 474 cc and a compression ratio of 9:1. When the machine was disassembled for restoration it was found the engine work had been performed to a high standard, and it was decided to keep the engine capacity in the current state.
A total professional restoration was started in January 2022. The engine was in generally good condition, but work was required in various areas including the cambox and camshaft drive. Other work included fitting a Sturmey Archer EIV gearbox in place of the incorrect Burman unit, making a new positive stop mechanism, fitting a new (Norton) clutch, repairing and refinishing the petrol tank, rebuilding the wheels with new wheel rims and spokes, overhauling the magneto and carb, fitting a new cover to the Dunlop saddle etc. New engine plates, mudguards, stays, oil pipes, toolbox, and a silencer were fitted. The larger plated items were chromed, with the smaller parts being chromated zinc. An A10 driptray was added to keep petrol off the magneto. A full lighting set was fitted featuring a gel battery and LED bulbs. With the anticipation of only limited miles to be covered after dark, coupled with the low drain of the LED bulbs, the restorer designed this as a total loss system, and no dynamo is fitted. The entirety of the work is documented and illustrated in a very detailed blog:
https://www.vintageajs.uk/2022/02/the-ajs-337-trophy-model-restoration.html
The 33/7 comes with a photostat copy of the 1933 handbook and an A4 coffee-table book which is a copiously illustrated account of the restoration. Only a few miles have been covered following the restoration and the bike therefore still requires shaking down and running in.