1924 Norton 633cc Big Four
Registration no. SV 7803
Frame no. 15008
Engine no. 6619
Norton relied on proprietary engines in its formative years - winning the inaugural Isle of Man TT with a Peugeot-engined machine - before introducing its own design of power unit in 1907. The long-stroke (82x120mm) sidevalve single displaced 633cc and the new model it powered became known as the 'Big 4'. Smaller capacity versions followed and in 1911 the 500 adopted the classic 79x100mm bore/stroke dimensions which would characterise the half-litre (actually 490cc) Norton for the next 50 years. Norton's sidevalve engines were revised for 1914 and in 1921 the Model 16, as it had become known, received a new lower frame, becoming the 16H. Considered by many to be an ideal sidecar 'tug', the Big Four (and 16H) would be continuously up-dated for the next 30-plus years, many seeing service with Allied forces in WW2. Post-war, the Big Four was revised with a shorter (113mm) stroke for a capacity of 597cc before taking its final bow, alongside the16H, in 1954.
This Big Four was acquired in a dismantled state in 1997 and restored by the current vendor over the next two years. The machine's last outing was the 2000 Banbury Run and it was last taxed for the road in 2001. We are advised that the carburettor, chain guard, front mudguard and toolbox are non-original, the rear wheel rim is of the wired-on type rather than beaded edge, and that the foot-boards are New Hudson. (New foot-board castings to original specification, complete with rubbers, are included in the sale). Benefiting from an overhauled magneto (2002), the machine is described as in generally good condition and offered with VMCC dating certificate, sundry restoration invoices and Swansea V5 registration document.