Page 1 of 3 Next >> In a shock announcement in September of 1938 the Italian motorsport association declared that during the following season all single seater races on Italian soil would be run for Voiturettes instead of Grand Prix cars. In retrospect the decision was understandable as the Italian manufacturers had played second fiddle in Grand Prix racing to the German Mercedes-Benz and Auto Union teams. For the smaller Voiturette class both Maserati and Alfa Romeo had just developed brand new and highly advance cars. A shift to the Voiturette class for all events would greatly increase the chance of national glory in Italy's premier events, including the prestigious Tripoli Grand Prix in May.
Despite having just six months to design, build and test a brand new car, Mercedes-Benz team director Max Sailer gave the green light in November of 1938; the 'Silver Arrows' would defend their title in the 1939 Tripoli Grand Prix. Although some design elements from the existing W154 Grand Prix car could be carried over, the new Voiturette most certainly needed a bespoke engine. French for small car, the name of the class could be taken very literally as the cars featured engines half the size as those found in the 'big' Grand Prix cars. To be exact, the displacement limit was set at 1.5 litre for the Voiturette class.
Although no parts were interchangeable, the new M165 engine owed much to the M154 3-litre Grand Prix engine. Apart from the displacement, the biggest difference was the number of cylinders; a V8 for the Voiturette compared to the original V12. What was carried over was the valvetrain with twin gear-driven camshafts per bank and four valves per cylinder. Designed for high revs, the cylinders were 'oversquare' with a bore of 64.0 mm and a stroke of 58.0 mm. Two Roots-Type Superchargers were fitted, boosting the power to a hefty 254 bhp. To cope with all this power the engine was constructed mainly from steel with the blocks and heads welded together. Page 1 of 3 Next >>