BMW IV
The BMW IV was a six-cylinder, water-cooled inline aircraft engine built in Germany in the 1920s. Power was in the 180 kW (250 hp) range. World record. On 17 June 1919 Franz Zeno Diemer flew a DFW F37, powered by a BMW IV engine to an unofficial world record height of from Oberwiesenfeld, reaching that altitude in 89 minutes. Diemer stated at the time, "I could have gone much higher, but I didn't have enough oxygen."