Racing Car Development

As mentioned last month the special builder is the genius at developing a racing car beyond all recognition or redemption. The Freikaiserwagen is a classic example, its pre-war design and post-war design having link similarity though, in fact, the aim and concept were the same.

Before the war Bristol was a hot-bed of racing enthusiasts and special builders and Dick Caesar was the inspiration for the hillclimb and sprint car built by David Fry, with the assistance of Robin Jackson and cousin Joe Fry. At the time the unconventional Auto-Union racing car designed by Dr. Porsche was very impressive in Grand Prix racing, and you either loved the mid-engined V16 Auto-Union, or you hated it; if you hated it you worshipped the conventional W125 Mercedes-Benz. Down Bristol way they were obviously Auto-Union fans, and Caesar and David Fry concocted a special for short speed events that they affectionately called “Porsche”, but it was known officially as the Freikaiserwagen, a play on the names of Fry and Caesar and the then-popular German word wagen for car. They could have called it the Frycaesarcar, but that would not have sounded so exciting.

Using a GN chassis and chain transmission, a Morgan 3-wheeler independent suspension layout was grafted on to the front. The driver sat as far forward as possible with a short steering column acting directly onto a circular rack-and-pinion. A V-twin 1,097 c.c. Blackburne engine from a racing Morgan was mounted transversely behind the driver, driving to the GN bevel-box and thence through the chain transmission to the solid rear axle. The engine was supercharged by a Marshall Roots type blower giving 14 p.s.i. running on alcohol fuel and Robin Jackson was the man behind this power-plant. As the engine was meteor less hidden behind the driving scat, and was air-cooled, a fuel tank in the form of an aircraft wing section was mounted on struts above the engine so that it deflected air downwards on to the cylinder-heads. The internals of the engine were all pretty special, thanks to Jackson, including the cams and it could rev to 6,000, an that with a dry weight of 730 lb. it was no mean performer, its maximum speed being over 100 m.p.h. Acceleration was its strong point, with a rearward weight bias and running on 600 x 16 rear tyres.

After the war it underwent a total rebuild as well as a total redesign, The Morgan i.f.s. was retained, as was the V-twin Blackburne engine, but the channel-section GN chassis frame was replaced with a tubular frame as used on the Bristol-built Iota 500 (F3, cars. Independent rear suspension was deemed desirable and as this was impossible with the GN chain transmission the whole layout was changed. The V-twin engine was turned through 90º so that it sat fore-and-aft and a chain drove from the crankshaft to a Norton motorcycle gearbox. Another chain drove to a counter-shaft above the rear axle and a third chain ran downwards to a ZF self-locking differential. Fixed-length tubular half-shafts drove to the wheels, these shafts forming swing-axles for the independent rear suspension, the ends being located by nailing arms.

The engine was again supercharged but this time by two Marshall blowers driven in series to give a more efficient 14 p.s.i. and they drew from a 48 mm. SU carburetter while the fuel was a heady mixture of methanol, nitromethane, acetone, benzoic and nitrobenzine and something like 120 b.h.p, was realised at 6,000 rpm.

In the early days both David and Joe drove the car while Jackson ministered to the engine and Dick Caesar watched benevolently and proffered advice. Of the two cousins Joe proved to be the better driver, apart from being much smaller and lighter than David and soon Joe was doing all the driving, leaving David to do the engineering. In its 1948/50 form the Freikaiserwagen was one of the stars of the sprint and hillclimbing scene and was a truly outstanding and successful special. Joe Fry’s driving had a real flair to it. Alas tragedy struck this happy little band of amateur sportsmen in 1950 when Joe Fry crashed at the Blandford hillclimb and was killed. David put the wreckage away and finished with the hillclimb and special-building scene. Since those days both Dick Caesar and Robin Jackson have passed-on and we can only look back on the Freikaiserwagen and its development with interest and admiration. – D.S.J..