Austin Champ - Design

Design

The engine was a four-cylinder in-line petrol unit of 2838 cc capacity (3.5-inch-diameter (89 mm) pistons × 4.5-inch (110 mm) stroke) designed by Rolls Royce and was the smallest of the standardised B-Range military engines. These engines had their origin in a 1936 design produced at Derby, with the concept and dimensions first developed for the Rolls-Royce 20 HP of 1922, but with the demands of the war, development was not proceeded with until the late 1940s. The engine was designed with absolute reliability as a prime criterion with fuel economy a secondary consideration, and using British Standard Fine (BSF) thread standards. A feature of this engine was the use of a cast aluminium cylinder head with screwed-in hardened steel valve seats.

With the adoption in 1949 of Unified thread standards, the engine was re-designed and simplified to ease manufacture; a cast-iron cylinder head was used in this version which can be most easily identified by the letters "UNF" cast or pressed into the rocker cover.

Rolls-Royce produced engines at Crewe early in the contract but did not have the capacity for volume production at the rate required, therefore Austin was lent tooling and licensed to build a virtually identical engine, and Austin-made engines were fitted in the great majority of Champs built.

The gearbox had five ratios with synchromesh on all gears. A conventional Borg & Beck clutch with mechanical linkage was used and drive from the gearbox was by shaft to the rear combined transfer box and differential assembly which incorporated reverse gear, thereby allowing five reverse gears also, and then by a long shaft to the front differential which incorporated a simple dog clutch to enable four-wheel drive when required. A conventional separate transfer case was not possible due to the cruciform layout of the vehicle chassis which placed the junction of the cruciform where the transfer box would reside on a conventional ladder-type chassis. Bendix "Tracta" type constant velocity joints were fitted at all wheel stations. All transmission assemblies were sealed against the ingress of water.

The suspension system was based on longitudinal torsion bars for primary springing and featured fully independent suspension at all four wheels using double wishbones. Each wheel station was also fitted with a rubber cone and cup system to buffer extreme upward suspension travel with energy control exercised by double-acting telescopic hydraulic dampers. This system gave an exceptional cross-country performance. Front and rear axles were constructed into a cradle sub-assembly, which could be rapidly exchanged in the field.

The braking system was by Girling and was a simple single-line hydraulic layout without power assistance.

The engine and all electrical items were waterproofed so the vehicle could wade to a depth of 6 feet (2 m) with minimal preparation; a snorkel attached to the air cleaner and normally carried horizontally on the right wing (US = fender) could be raised during wading operations.

Electrical equipment fitted on military Champs was a 24-volt system in accordance with agreements reached in 1948 with the US and Canadian armies and comprised standardised military pattern equipment used on many British post-war vehicles, supplied by Lucas, CAV, Delco-Remy and Simms. Instrumentation was a system common to many other military vehicles of the period and supplied by Smiths Instruments of London.

The body was a utilitarian open four-seater tub of welded pressed steel panels and similar in style to the war-time Jeep layout although unlike the Jeep, the Champ body is designed to carry part of the vehicle stresses and chassis flexing. The inner windscreen opened forwards for ventilation or the whole frame and glass assembly could be folded down onto the bonnet (hood). Military items such as a shovel, pickaxe and a carrier for a standard 20-litre jerrycan (for the carriage of water not fuel) were normally fitted. A 20-gallon (91 litre) fuel tank was fitted at the rear of the vehicle, giving an operational range of approximately 300 miles.

Various bolt-on kits were produced to convert basic vehicles for specialist roles, for example tactical radio carrier, telephone line laying, field ambulance with two stretchers, and an appliqué armour kit. The armour components were listed in the Austin civilian parts catalogue but not in the army one. A standard radio fitting kit for 1/4-ton vehicles comprising a 50-inch table running on sliding runners, battery mountings and appropriate fittings was introduced in 1956. Some prototype vehicles with a Land Rover-style rear body with tailgate rear access were constructed in an attempt to improve the versatility of the basic design but were not put into production.

Champs made for the civilian market (model WN3) could be specified with the Rolls Royce engine or, as was much more usual, a modified version of Austin's 2660 cc A90 engine. Military body fittings such as rifle clips were omitted and the windscreen was a fixed assembly. Commercial 12-volt electrical components by Lucas were provided.

Around 500 of the civilian version are thought to have been made, including a left-hand-drive version. They were priced at £750 in November 1952 and at £1000 in November 1954. Many went to Australia, where some can still be found. Two are known to have survived in the UK. Some of the design features of the Champ were carried over to the Austin Gipsy, of which some 21,000 were made from 1958 to 1967.

A Champ is featured throughout the video for the song "Reward" by English post-punk/neo-psychedelic band The Teardrop Explodes. The song reached no. 6 in the UK single charts in January 1981.