The Daimler-Mercedes D.III was a six cylinder, liquid-cooled inline engine, developed and used on a variety of German aircraft during World War I. Three production variants of this engine are generally recognised to have been designed. These were: the 170hp D.IIIa, introduced in June 1917 and upgraded to produce an output of 180hp during it’s service life. The second variant was the upgraded 180/200 hp D.IIIaü, introduced in late 1917. The the ü stood for “über”, meaning “overcompressed”. This variant featured a new altitude-compensating carburettor, this engine changed the pistons from the standard 170hp D.IIIa, this time to a domed profile that further increased the maximum compression. The third example of the Daimler-Mercedes D.III was the 200 hp (200-217 hp) D.IIIav (or avü), introduced mid-October 1918. This version used longer aluminium pistons, which further increased compression.
Stage 5 of the full-colour Wingnut Wings instruction booklet deals with the engine build. The 12 stages took approximately 10 hours. Wingnut Wings provides 2 pages of colour photographs, which detail the D.IIIaü version of the Daimler-Mercedes from all aspects. 11 detailed photographs are provided, detailing this engine from every angle.