Mercedes-Benz M 198
| Daimler Benz | |
|---|---|
.jpg) M 198 in a Mercedes-Benz W 198 |
|
| M 198 | |
| Production period: | 1954-1961 |
| Manufacturer: | Daimler Benz |
| Working principle: | Otto |
| Motor design: | R6 |
| Valve control: | OHC |
| Displacement: | 2996 cm 3 |
| Mixture preparation: | Direct petrol injection |
| Engine charging: | Free sucking |
| Power: | 158 kW |
| Previous model: | none |
| Successor: | none |
The Mercedes-Benz M 198 is a gasoline engine from Daimler-Benz AG , which was built from 1954 to 1961. It is considered to be the first passenger car four-stroke engine with gasoline direct injection . It was designed by Hans Scherenberg .
technology
The M 198 is a liquid-cooled six - cylinder in - line engine with a counter-flow cylinder head . The fuel is injected directly into the combustion chambers. The cylinders are inclined at an angle of about 50 °, the intake manifold and exhaust manifold are arranged approximately in a semicircle above the crankcase axis. It is a dry sump lubrication system used. Each cylinder has the engine an inlet and an outlet valve, they will be of an overhead, duplex chain driven camshaft via drag levers actuated.
The structure of the combustion chamber is similar to that of the M 186 . The cylinder block is beveled at its upper end, the cylinder head is flat on the underside and is placed on the block at an angle of about 289 ° to the cylinder axis. The combustion chamber is roughly hemispherical and protrudes sideways beyond the cylinder; however, it is very compact. The piston is roof-shaped on one side over a little more than half the cylinder bore and thus forms a pinch gap. The inlet valve is largely located in this squeeze gap. The gap height is very small at those points where the roof-shaped piston head and inlet valve disk form the squeeze gap. The injection nozzle, which is at an angle of around 102 ° to the cylinder axis, is precisely aligned with the squeeze flow, the spark plug is installed in the cylinder head at an angle of around 147 ° to the cylinder axis and protrudes into the combustion chamber so that it is close to the exhaust valve is.
The M 198 is operated with almost the same air ratio in every load condition ; the torque is set via the amount (change in quantity ) of the fuel-air mixture generated , as with a carburettor engine . In order to provide sufficient time for the mixture homogenization, the fuel is already injected into the intake stroke. The injection quantity is regulated by the crankshaft speed and the intake manifold vacuum via a flap connector. Injection, fuel is targeted to hot spots like the exhaust valve and piston crown to cool these parts, which improves performance regardless of fuel consumption. To compensate for low air pressure at high altitudes, the injection pump has a barometric can that corrects the injection quantity when the air pressure drops.
Bosch was the supplier of the valve body, the six-piston in-line injection pump with leakage oil barrier and the outward-opening injection nozzles without a leakage line. In principle, these parts corresponded to the components that had already been used in the two-stroke engines of the small cars from Goliath and Gutbrodt.
Technical specifications
| Parameters | M 198 |
|---|---|
| Engine type | In-line six-cylinder engine (Otto) |
| Mixture preparation | Direct gasoline injection , mechanical control, six-piston injection pump, injection pressure 45 bar |
| Displacement | 2996 cm 3 |
| Bore × stroke | 85 mm × 88 mm |
| Nominal power (DIN 70020) | 158 kW (215 hp) at 5800 min -1 |
| Max. Torque (DIN 70020) | 280 N · m at 4600 min -1 |
| Valve control | 2 hanging valves per cylinder, overhead camshaft, drive by duplex roller chain |
| Engine lubrication | Dry sump lubrication |
| source |
- Speed diagram
Source:
Images on Wikimedia Commons
Individual evidence
- Kurt Lohner, Herbert Müller (authors): Mixture formation and combustion in gasoline engines , in Hans List (ed.): The combustion machine , Volume 6, Springer, Vienna, 1967, ISBN 978-3-7091-8180-5 .
- Richard van Basshuysen (Ed.): Otto engine with direct injection and direct injection: Otto fuels, natural gas, methane, hydrogen , 4th edition, Springer, Wiesbaden, 2017. ISBN 9783658122157 .