Mercedes-Benz M09 engine

{{Infobox automobile engine

|image =

|name = Mercedes-Benz M09

|manufacturer = Mercedes-Benz

|production = 1928-1929

|configuration = Inline-6

|bore = {{convert|80|mm|in|1|lk=on|abbr=on}}

|stroke = {{convert|115|mm|in|1|lk=on|abbr=on}}

|displacement = {{convert|3.4|L|cuin|0|lk=on|abbr=on}}

|valvetrain = 12-valve, SOHC, two-valves per cylinder

|power = {{convert|60|hp|kW|0|lk=on|abbr=on}}

|torque = {{convert|100|lb.ft|N.m|0|lk=on|abbr=on}}

|fuelsystem = Carburetor

|fueltype = Gasoline

|compression = 5.0:1

|oilsystem = Dry sump

|weight =

|predecessor = Mercedes-Benz M04 engine

|successor = Mercedes-Benz M10 engine

}}

The Mercedes-Benz M09 engine is a naturally-aspirated, 3.4-liter, straight-6, internal combustion piston engine, designed, developed and produced by Mercedes-Benz; between 1928 and 1929.{{Cite web|url=https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/1460-hp-Type-350.xhtml?oid=4211|title=14/60 hp Type 350|website=Mercedes-benz-publicarchive.com|access-date=10 November 2021}}{{Cite web|url=https://www.carfolio.com/mercedes-benz-14-70-hp-type-mannheim-350-164395|title=1929 Mercedes-Benz 14/70 hp Type Mannheim 350 W 10 specifications | technical data | performance | fuel economy | emissions | dimensions | horsepower | torque | weight|website=Carfolio.com|access-date=10 November 2021}}{{Cite web|url=https://sportlichleicht.com/info/engines/m09/|title=Mercedes-Benz M09 Engine|website=Sportlichleicht.com|access-date=10 November 2021}}{{Cite web|url=https://robbreport.com/motors/cars/mercedes-benz-1928-sports-tourer-bonhams-quail-auction-1234627933/|title=Bonhams Presents Mercedes-Benz's Golden Age with a 1928 Sports Tourer |website=Robbreport.com|date=2 August 2021 |access-date=10 November 2021}}{{Cite web|url=https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/1470-hp-Mannheim-350.xhtml?oid=4167|title=14/70 hp Mannheim 350|website=Mercedes-benz-publicarchive.com|access-date=10 November 2021}}{{Cite web|url=https://mercedes-benz-archive.com/marsClassic/en/instance/ko/1460-hp-Type-350.xhtml?oid=4211|title=14/60 hp Type 350|website=Mercedes-benz-archive.com|access-date=10 November 2021}}{{Cite web|url=https://mercedes-benz-publicarchive.com/marsClassic/en/instance/ko/1255-hp-320-and-1460-hp-350-W-03-W-04-W-05-1926---1929.xhtml?oid=4206|title=12/55 hp 320 and 14/60 hp 350 (W 03, W 04, W 05), 1926 - 1929 |website=Mercedes-benz-publicarchive.com|access-date=10 November 2021}}