Mercedes-Benz M196 engine


The Mercedes-Benz M196 engine is a naturally-aspirated, straight-8, racing engine, designed, developed, and produced by Daimler-Benz; and used in both sports car racing and Formula One racing, between 1954 and 1955. Daimler-Benz made two versions of the engine, the M 196 R, displacing 2.5 litres, and the M 196 S, displacing 3.0 litres.
Mercedes pulled out of all motorsports after the 1955 [Le Mans disaster]. This was their last Formula One engine, and Mercedes did not return to motorsport as an engine manufacturer until, when they supplied engines to the Sauber Formula One team.

M 196 R

The new 1954 Formula One rules allowed a choice of naturally aspirated engines – up to 2.5 litres or 0.75 litres supercharged. The expected target range for competitive engines was.
By its introduction at the 1954 French GP the desmodromic valves straight 8 M 196 R delivered. The M 196 was the only F1 engine with direct fuel injection, giving it a considerable advantage over the other carburetted engines.
For the 1955 season, Daimler-Benz improved its M 196 R engine by reducing the intake manifold length, increasing the engine power slightly to.
The latest iteration of the 2.5-litre unit eventually had a compression in the range of ε=12.0…12.5, produced up to at 8500/min, and delivered a maximum torque of at 6450/min, equivalent to a BMEP of.

M 196 S

For the W 196 S race car, the M 196 engine was bored and stroked to 78 mm each, and reduced in compression from ε=12 to about ε=9. The latter allowed using standardised petrol instead of high-octane race fuel required for the M 196 R. The M 196 S has a power output of at 7,000 rpm, and produces a maximum torque of at 5,950 rpm. This is equivalent to a BMEP of.
The M 196 S is canted to the right at a 53° angle. It has two four-cylinder banks made of silumin with chromium-coated aluminium cylinder sleeves. Unlike typical car engines, the M 196 S has a crankshaft consisting of two Hirth joint halves with centre torque take-off. The silumin cylinder heads are crossflow heads and cast together with the cylinder banks. Daimler-Benz fitted the engine with a dry-sump lubrication system, water cooling, and a direct fuel injection system. The ignition system is a traditional magneto system.

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