The brothers Alan and Richard Jensen began their motor-building activities by re-bodying an Austin Seven in a form which proved particularly pleasing to the eye. The chief engineer of the Standard Motor Company was suitably impressed with its appearance and in due course had a Standard chassis delivered to the Jensens to be re-bodied in the same way.
It was from this pleasant association that Avon Standards of the thirties came to be made. It was not, however, until 1936 that a car bearing the name of Jensen first appeared using a modified Ford V-8 3.5-litre engine. Just before the Second World War a straight-eight Nash engine was used in another model. When production was resumed after the war the Jensens developed an association with Austin and used Austin engines in some models.
The Jensen 541 went into development early in 1953. Originally referred to as simply ‘The New Car’ it ultimately became the 541 as it was to be a 1954 model of the first series and was notable for pioneering glass-fibre construction. The number 541 rolled easily off the tongue and it remained, with suffixes R and then S, until the advent of CV8s. It was to be a smallish car with the Austin four-litre engine in it. The car was to be a four seater, as light as possible, with high gearing – a sound Jensen brothers formula.
The story of the Jensen brothers development of the 541 is a fascinating one when one thinks today of the development of modern cars. There was no computer design involved. Shapes and styles did not have the benefit of modern computer technology in rendering 3-D models and producing designs with a low drag coefficient. Instead smoke was blown over mock-up body designs which were continually adjusted until the desired effect was obtained.
Because it was to use a glass fibre body which didn’t provide any structural stiffness, a ladder frame comprising tubular side members with boxed cross members was chosen for the chassis frame. The steering assembly was easy; the Jensen brothers had some 150 Austin steering units left over from a previous saloon so these were to be used up.
The engine chosen was a 4.0-litre one from Morris engines. They machined the head as much as possible so as to raise the compression ratio and decided to fit three horizontal SU carburettors using three manifolds per engine of their own manufacture but based on the Austin manifold. Subsequent tests showed that their tuning raised the engine power by 25 per cent over that quoted for the original engine.
The Jensen brothers were in no doubt that the 541 had to be successful. If it was not there would be no more Jensen cars.
Many people think of the 541 as the Jensen’s first car but, of course, it was not. There were many types of Jensen made before the 541, both pre-war and post-war. However the 541 always received good publicity and there were many more than any previous model.