The M116 V-8 Engine in Mercedes-Benz R 107 Roadsters

 Taken from a brochure. Nice visual!

Mercedes-Benz M 116 V8 engine. In 1969, this power plant was initially available in the 300 SEL 3.5 (W 109), 280 SE 3.5 Cabriolet and 280 SE 3.5 Coupé (both W 111) models

In the 1960s, it was not clear whether the new rotary piston engine according to Felix Wankel would really hold its own against conventional piston engine designs. This is why Mercedes-Benz decided in favour of a parallel development approach. The M 116 and M 117 piston engines can trace their beginnings back to engine designer Adolf Wente, who developed the first V8 injection engine offered by the brand ─ the 6.3-litre M 100 found in the Mercedes-Benz 600 (W 100).

The M 116 and M 117 had an overhead camshaft and two banks of four cylinders mounted at a 90-degree angle to each other. On the M 116, the bore-to-stroke ratio measured 92 × 65.8 millimetres, giving the engine an extremely short stroke. In addition to its wonderful ability to rev, the power plant was also a very smooth runner. The M 116 was the second engine from Mercedes-Benz to have the D-Jetronic electronic fuel injection system by Bosch. The M 117, on the other hand, had a bore-to-stroke ratio measuring 92 × 85 millimetres, which made the unit an extremely pleasurable “cruiser”.

 Both the M 116 and M 117 were comparably lightweight engines. The 4.5-litre engine with a cast-iron block weighed just 250 kilograms, whereas the M 110 six-cylinder unit of the time tipped the scales at 240 kilograms.

The market launch: Both engines were earmarked for the new SL (R 107) and SLC (C 107) ─ which débuted in 1971 ─ as well as the S-Class (116 model series). The launch of the S-Class was postponed, however, and the model was not showcased until 1972. Since the predecessor six-cylinder engines were technically outdated after having been around for a long time, the company decided to start using the new engine variants as soon as 1969 in the W 109 and W 111 model series as well as in the W 108 later on. All of these vehicles were predecessors to today’s S-Class.

The career: The forward-looking design made it possible to keep both engines up to date for decades with only minor modifications and adjustments required. The M 116 and M 117 found their way into the S-Class, SLC-Class and S-Class Coupés, SL sports cars and G-Class.

The successor: In 1989, the thoroughly modernised M 119 V8 engine featuring two overhead camshafts was introduced and is largely the work of Wente’s staff member Ralf Ohlendorf. The power plant was initially offered with two engine block heights of the M 116 for 4.2 litres and of the M 117 for 5 litres displacement. When the LH-Jetronic system was launched in 1991, a standardised version of the engine was offered based on the lower M 116 engine block