In the history of heavy vehicle engines, Britain stands out as the only nation where heavy vehicle engines with eight cylinders in line have been manufactured in significant volume.
Until 1953-54, although in diminishing numbers, with straight-eight gasolineengined premium luxury cars were produced by General Motors and others in the US – and by Daimler in the UK for its most prestigious limos. In 1955, the configuration also ran its last as a Formula One World Championship winning power unit.
Surprisingly, from 1920 onwards, despite their use in higher performance cars, straight-eights – gasoline or diesel fuelled – never caught on in the US for trucks. Indeed, aside from what might be considered a missed British opportunity, a batch of Canadian military 6x6 prototypes were the only instance of straight-eights being installed in trucks in North America.
Even in Germany, apart from spark ignition ‘eights’ in cars, only Deutz appear to have dabbled with straight-eight automotive diesels. Scania produced type D812 straighteightsfor railway applications – and in 1951, chalked up a world first by adding a turbocharger. It subsequently tested this in a prototype military 6x6.
So – what are the ups and downs of eight cylinders in line?
With more power strokes per revolution, a straight-eight’s standout virtue is inherent smoothness under load. Cream compared to a V8, and one cylinder head rather than two – but a longer crankshaft. While astraighteight’s timing can be set to give optimal primary and secondary balance, harmonic damping of the crankshaft is required to
