I tried my best making a replica of the Napier Sabre II 24 cylinder H-engine, but since there are no gears in simple planes, I had to make them myself, which resulted in alot of problems with spinning direction when approaching high RPM. I went for functionality with this engine, meaning that it doesn't work exactly like the real thing, nowhere near actually. Back in 1941, the Napier Sabre was the most powerful inline piston engine of it's time, and the most complicated one. All parts were made by hand and assembled by craftsmen. The Sabre was the engine that powered the Hawker Typhoon and Tempest V fighter bombers, these were also known as the fastest piston aircraft at low altitudes.