| Mercedes-Benz M23 | |
| Manufacturer: | Mercedes-Benz |
| Production: | 1933-1936 |
| Configuration: | Inline-4 |
| Bore: | NaNmm |
| Stroke: | NaNmm |
| Displacement: | NaNL |
| Valvetrain: | 16-valve, DOHC, two-valves per cylinder |
| Power: | NaNhp |
| Torque: | 74lb.ft |
| Fuelsystem: | Carburetor |
| Fueltype: | Gasoline |
| Compression: | 6.0:1[1] |
| Oilsystem: | Dry sump |
The Mercedes-Benz M23 engine is a naturally-aspirated, 1.3-liter, inline-4 gasoline engine, designed, developed and produced by Mercedes-Benz; between 1933 and 1936.[2] [3] [4] [5] [6] [7] [8] [9]
At the beginning of the 1930s, there were attempts to move car engines from the forward compartment to the rear of the car. Such a move allows a reduction in the volume of the front compartment. At the same time, the voluminous rear provides a lot of space above and behind the rear axle. Moreover, when engines are rear-mounted, the drive shaft is eliminated.
In 1930, Daimler-Benz entrusted Hans Nibel with the development of a small rear-engined car, starting from the same principles. In 1931, working with Max Wagner, the type W17 or 120(H) was created, a two-door, equipped with a four-cylinder boxer engine in the rear with a displacement of 1200 cc and a power of 25 hp (18.4 kW). There were also attempts with transverse four-cylinder inline engines. In 1932/1933 Mercedes built a prototype with a front similar to the later VW Beetle, and a longer tail.[10]
Created in 1931 by Nibel, it had the 1.3 liter sidevalve[11] four-cylinder engine mounted at the back, hence the "H", from German heck (rear),[12] With the fan between the rear coil springs,[13] it drove a transmission with three forward speeds, plus a semi-automatic overdrive which did not require the use of a clutch.[11]
It was derived in 1935 from the 130, and a more powerful engine. Displacing 1498 cc and a power of 55 PS (40 kW). The engine powered the car to a top speed of 125 km/h.
Created in 1934 by Nibel and chassis engineer Max Wagner.[12] the 150H was a two-seat sports roadster.[12] It featured transverse leaf spring front and coil-sprung swing axle rear suspension. A water-cooled 1498abbr=onNaNabbr=on OHC four-cylinder engine, producing 55hp, was mounted in back, hence the "H", from German heck (rear).[12] The radiator was behind that, above the transaxle, with a squirrel-cage blower[12] (reminiscent of the VW Type 1) feeding both radiator and carburetor.[12]
The gas tank, which in the case of the Mercedes-Benz 130 was installed over the engine, was transferred to the front compartment.
In 1936, in parallel to the classical front-engine Mercedes-Benz 170 V, Daimler-Benz AG introduced the Mercedes-Benz 170 H which had the same engine as the 170 V, with an architecture derived from the one of the 130, its predecessor. The 170 H was powered by a four-cylinder 1697 cc engine with a power of 38 PS (28 kW). The "H" stood for "Heckmotor", or rear engine.[14]