Borgward RS 1952-1958

In 1952, Hans Hugo Hartmann gained victories at the Grenzlandring and Avus circuits in his Borgward RS with the pushrod engine, which now gave 100 bhp. A fuel-injected unit, based on the Isabella engine, was being used by 1954, still with the same bore and stroke as the basic Isabella block. This engine, which produced 115bhp, was good enough to give Bechem victory in the 1954 Eifelrennen at the Nurburgring. In 1955, the car gained a class victory in the Mille Miglia, and, for 1956, an entirely new racing engine was devised.

This new engine still had the same 84.5 mm bore and 75 mm stroke of the 1488 cc Isabella but the engine had a Silumin (silicon-aluminium) block, wet liners and a new twin-overhead-camshaft cylinder head with four valves per cylinder. It also featured fuel injection, dry-sump lubrication and twin ignition systems. The sturdy engine had a five-bearing crank-shaft with chain drive to the camshafts and, on a 10.2: 1 compression ratio, it gave 150 bhp at 7500 rpm. The car had little success in its first two seasons, although Hans Herrrnann did gain second place in the European Mountain Championship in 1957.

The tiny, open Borgward RS was often out of luck in circuit racing, but when Jo Bonnier joined the team, in 1958, he gave the all-conquering 1500cc Porsches a run for their money in the German sports-car championship.

Bonnier lost first place at the Avus by only 0.8 sec and Borgward had to be content with second place in the championship. Bonnier also had to be content with second place in the European Mountain Championship but he won the important Freiburg hill-climb by a very big margin.

On the production side, the Isabella continued throughout the 1950s, supplemented by the pretty TS coupe, but sales could never quite keep the company far enough ahead of their creditors and, in 1960, the smaller Lloyd Arabclla was given the Borgward name in an effort to boost sales of this cheaper car.

Borgward retired from racing in 1958, not from choice but because of financial problems. However, the twin-cam racing engine was lent to private owners, to fit into single-seater chassis, most notably Stirling Moss who raced a Cooper in the 1½ litre Formula Two with this engine. The engine gave around 175 bhp by this time and Moss was able to gain some success with it.