Daimler-Benz DB 603

The Daimler-Benz DB 603 was a German aircraft engine used during World War II. It was a liquid-cooled 12-cylinder inverted V12 enlargement of the 33.9 Liter DB 601, which was in itself a development of the DB 600. Production of the DB 603 commenced in May 1942, and with a 44.5 liter (44,500 cc) displacement, was the largest displacement inverted V12 aircraft engine to be used in front line aircraft of the Third Reich during World War II.

The DB 603 powered several aircraft, including the Do 217 N&M, Do 335, He 219, Me 410, BV 155 and Ta 152C.

Design and development

As Germany's largest displacement inverted V12 aviation powerplant in production during the war years, the DB 603 saw wide operational use as the primary engine type for many twin and multi-engined combat aircraft designs — the promising twin-engined Dornier Do 335 Pfeil prototype heavy fighter, the front-line Messerschmitt Me 410 Hornisse heavy fighter and Heinkel He 219 Uhu twin-engined night fighter were all designed to be powered by the DB 603.

The Dornier Do 217M and -N medium bomber and night fighter subtypes powered by inline engines, and the enormous sixty-metre wingspan, six-engined Blohm & Voss BV 238 flying boat prototype, essentially had their DB 603 powerplants installed within what appeared to be the same unitized complete engine/cowl/radiator assembly as a complete unit-replaceable "power system" for twin and multi-engined aircraft — this particular design featured a "chin"-style radiator installation directly beneath the crankcase, and the oil cooler placed on the dorsal portion of the installation for the earlier examples, as the BV 238 had no visible upper-cowl openings for engine cooling of any sort for its half-dozen unitized DB 603s.

The He 219 airframe pioneered what is believed to be a Heinkel-specific Kraftei unitized engine package for the DB 603 engine using a well-streamlined annular radiator set for primary engine cooling between the propeller and its reduction gear housing with a nearly-cylindrical cowl behind it, pierced only by the twin rows of six exhaust stacks, one row per side. The characteristic portside-cowl supercharger intake for Daimler-Benz inverted V12s was usually accommodated away from the nacelle's sheetmetal itself for the Heinkel/DB 603 unitized engine package, most often within the airframe's wing panel design. The same Kraftei packaging for the He 219 was also used for powering the four-engined prototype He 177B strategic bomber series, and with an added turbocharger in each nacelle, the six ordered (two completed) prototypes of Heinkel's He 274 high-altitude strategic bomber project.

The Mercedes-Benz T80 land speed record car, designed by aircraft engineer Josef Mickl with assistance from Ferdinand Porsche and top German Grand Prix racing driver Hans Stuck, incorporated the third prototype DB 603. It was set up for the land speed record run attempt to operate on an exotic fuel mix based on a 63% methanol, 16% benzene and 12% ethanol content, with minor percentages of acetone, nitrobenzene, avgas and ether. Adding to the power output was a pioneering form of the Luftwaffe's later MW 50 methanol/water injection boost, and was tuned to 3,000 PS (2,959 hp, 2,207 kW)— enough, it was believed, to propel the aerodynamic three-axle T80 up to 750 km/h (466 mph) on a specially-prepared, nearly 10 km (6.2 mi) length stretch of the roughly north–south oriented Autobahn Berlin — Halle/Leipzig, which passed close to the east side of Dessau (now part of the modern A9 Autobahn) and with the actual length's location due south of Dessau, reworked to be 25 m (82 ft) wide with a paved-over median, for the record to be set in January 1940 during Rekord Woche (Record/Speed Week). Due to the outbreak of the war in September 1939, the T80 (nicknamed Schwarzer Vogel, "Black Bird") never raced.