APPEARING for the third year at the Motor Cycle Show, the 1,000 c.c. Square Four Ariel again attracted an immense amount of attention. For 1938 this model is unchanged, and the four-cylinder monobloc engine remains a fine example of modern multi-cylinder design. The engine employs the unusual arrangement of double crankshafts coupled by gears, and the drive is taken from the rear crankshaft. Many features popular in modern car design are employed, including white-metal big-end bearings.

How the valves are enclosed on the 597 c.c. side-valve model

Solex carburettor, and a car-type distributor. The whole design is neat and compact, and the unit is housed in a normal-type frame. The "thousand " is the only multi-cylinder model available in the Ariel range for 1938. Its price, with full equipment, is £97 17s. 6d.

The 1,000 c.c. Ariel is the sole four-cylinder model at the Show. Among the improvements for 1988 are a longer front-fork spring, which improves the steering, and a front brake that is both more powerful and easier to operate

A number of improvements have been made to the ever-popular "Red Hunter" models, and they again attracted the sporting riders. The 250 c.c. Model LH is typical of the range in that it has a new cylinder head with redesigned enclosure of the overhead-valve gear. This enclosure consists of two neat aluminium boxes which carry the rockets. These boxes are bolted on to the cylinder head and the push-rods pass through holes in the head casting to the rockers, so that the valve enclosure is simple and oiltight. Large knurled nuts on the rocker bosses give access to the tappet. adjustment at the valve end of the rockers. This form of enclosure is used on all the new over- head-valve Ariel singles. The cylindrical silencer of the 250 c.c. "Red Hunter " has an open tail-pipe in- stead of a fishtail, and the silencer is filled with spun-glass material.

Model "VB de Luxe." -598 c.c. single-cyl. side-valve Ariel; dry-sump Lubrication; magneto ignition; all-chain drive; oil-bath primary chain case; 4-speed gear with foot control; fuel, 3¼ gals; 3.25-19 tyres. Price with lighting, speedometer, horn and licence holder (solo). £65 2s. 6d.

A close-up of the o.h.v. enclosure

This well-tried side-valve model has undergone very little change from last year, but a modification to the cam gear is claimed to improve the already high performance. In most respects the equipment is the same as on the "Red Hunter" models, for the machine is produced as a de luxe model. Totally enclosed valve gear, a four-speed gear box with foot change, 3.25 -- 19 tyres, and heavily valanced mudguards are among the important features.