M203B

Berlin-Marienfelde had been building Daimler commercial and stationary engines since before the First World War, and the M 203 belongs to that half of the company rather than to any model line. It is a pre-chamber diesel of 140 mm bore and 210 mm stroke running 17:1 compression, rated at 1,200 rpm, weighing just under a tonne dry — the proportions of an engine built to hold a governed speed for hours rather than to accelerate anything. It could be started electrically, mechanically or on compressed air, and built to turn in either direction.

The A version was made from 1948 and the B from 1954; 453 units left Marienfelde in 1950 alone. A Daimler-Benz press kit of 1957 quotes the M 203 B not at one output but across a 40 to 90 PS band, which is how industrial engines were sold — the customer picked a governed speed and took the power that came with it. It sits between the M 202 B and the M 204 B in a closely related trio, and survives today mostly as a press photograph and a column of figures: a large, slow three-cylinder built for machinery rather than for a car.