AJS V4

This first version used a common crankcase with four individual cast iron cylinders and separate alloy heads, with exposed hairpin valve springs, and a 180° crankshaft with forked conrods.

[1] In the spring of 1936 a new racing version with alloy barrels appeared at Brooklands for testing, wearing a Zoller supercharger, driven at half engine speed, and fed by a single Amal TT carburettor.

The engine was now mounted in the same frame as the 500 cc OHC single TT racers, and used a four-speed Burman gearbox with a dry clutch.

[1] In 1936 Harold Daniell and George Rowley rode the AJS supercharged V4s in the Isle of Man Senior TT, but despite its high top speed, it lacked acceleration.

[1] Considerable work must have been done at the new AMC race shop, because the next version did not appear until 1938 and, when it did, it had a plunger rear suspension, better brakes, revised and lighter induction manifold, and raised compression.

The new duplex frame had integral rear plunger suspension housings, and the Webb-type girder forks were now graced with a deep finned alloy 8-inch (200 mm) TLS front brake.

When Sammy Miller acquired the engine from Jock West thirty years later to rebuild the AJS V4 for his museum, he found the crankpin still seized.

[1] The engine used by Walter Rusk in the Ulster GP, with 7.9:1 compression and 16.5 lbf/in2 (114 kPa) of boost, made 55 bhp (41 kW) at 7200 rpm on a dynamometer.

Motor Cycle News reported that the 'Sammy Miller' machine was refurbished and ran during August, 1979 "for the first time since it seized in Albi, France in 1946".