1930s The first J model appeared in 1930. Throughout the decade there was a large variety of models from small two-strokes to large side valves, from A-Z. A 225cc two stroke, B 225 cc sv, BO 250cc ohv Bullet, C 350cc sv, CO 350cc ohv, G 350cc ohv Bullet, H 488cc sv, J 488cc ohv, J2 488cc two port ohv, K 976cc sv v-twin, L 570cc sv, T 148cc ohv, Z (Cycar) 148cc two-stroke and many more variants.
1931 All the singles had inclined engines, some of which had been modified.
A radical new model called the Cycar appeared in 1932
1933 The first Bullet 500cc single, with exposed four-valve rocker gear and inclined engine, was introduced.
1935 They changed to three valves. These engines had their integral oil tank in front of the crankshaft, while post-war Bullet oil tanks were behind the crank. They were dry sump, the integral tank being separate from the crankshaft space. Royal Enfield entered a 500cc four valve racing model for the 1935 Senior TT. This was the last TT Royal Enfield entered.
In 1936 a new series of singles was introduced. These had vertical engines with oil sump in the crankcase. The range covered all the sizes described above.
1938 Royal Enfield 500cc single port J model ohv. During the 1920s a mid-range of Enfields left the Redditch factory: model 350 (350cc SV), 351 (350cc OHV) and 352 (350cc twinport sports). The two-valve J model rockers were enclosed, and the engine became upright. Model K side-valve V-twin had grown to 1140cc and was then called KX.
1931 Model K 976 cc SV V-twin
1932-1933 Models
1935 Models