Royal Enfield 1938 “KX” 1140 cc side valve v-twin frame # 10428 engine # KX 635
The last word in luxury motorcycling’ was how Royal Enfield headlined the Model K in their 1938 sales brochure.
It was powered by a mighty 1,140cc side valve, twin-cylinder engine with totally enclosed valve gear and Royal Enfield’s dry-sump lubrication system.
This powerful unit was combined with a heavyweight, four-speed, hand-controlled gearbox to ensure that the Model K with standard ratios was ideal for both sidecar and solo use. Lucas 6 volt Magdyno lighting was standard as was black enamel finish with gold lining.
The top-of-the-range Model KX featured detachable and interchangeable wheels and hand and foot controlled clutch.
The engine with bore x stroke dimensions of 88.5mm by 99.25mm benefitted from a bottom-end redesign to incorporate dry sump lubrication, with separate conrods supported by their own pairs of roller bearings inside the massive aluminium crankcase, and no fewer than four oscillating-plunger oil pumps.
The four-speed Albion gearbox was hand operated with a set of standard ratios that were intended to suit sidecar use; solo gearing could be supplied upon special order.
The KX could reach 80mph as a solo machine but more importantly could cruise at 60mph fully laden and in a relaxed manner, returning around 65 mpg. The machine weighs about 200 kg, has a tank capacity of 18 litres and a compression ratio of 1:5. This mighty slogger is an older restoration in very decent condition.