Post 5 - Powered Focke-Wulf FW 61 Development Model

This is the actual, two cycle-powered, factory model used in the development of the Focke-Wulf FW 61--widely recognized to be the first practical, fully functional helicopter.

Photo from the Deutsches Museum in Munich, Germany where it is part of the permanent collection.

Post 4 - Lancaster Counter-Rotating Twin Crankshafts/One Valve Per Cylinder

An early post from my other blog, Auto Neurotic Fixation.

"Designed c.1899 by one of the all-time great automotive engineers, Frederick Lanchester, the 4000cc horizontally-opposed twin cylinder had dual connecting rods per cylinder and dual counter-rotating crankshafts, which were joined by bevel gearing.  Just as it was designed to do, the unusual configuration provided smooth running - something that was previously considered unattainable in the early days of the internal combustion engine."

Post 3 - Soviet Experimental Low Profile Piston Aircraft Engine

Quote and photo from Monino Aviation Museum

"Unusual experimental engine with cylinders parallel to output shaft. A piston can be seen in the cut-away at upper left. The design was intended to allow for a more streamlined engine nacelle."

Note the grooved track crankshaft and connecting rod idler wheel arrangement.

Post 2 - Junkers/Wankel KM8 Disc Valve Exhaust Recycling V8 Torpedo Engine

c. 1942

Quotes and photos from Rotary-Valve Internal Combustion Engines

"The engine had eight liquid-cooled cylinders of 90mm bore by 85mm, stroke arranged as a V-8 with a 90deg angle. The total swept volume was 4.34 litres and the compression ratio was 6.6 to 1. Output was 275 HP at 3650 rpm. It ran on a mixture of petrol, oxygen, and its own exhaust gas--the latter presumably to dilute the oxygen to a manageable content."

"The disc valves are fitted between upper and lower cylinder heads. They had teeth on their periphery, and formed two gear trains without the need for idlers or extra gearwheels. The train of valve discs was driven by bevel gears from the crankshaft, with splined connections to allow valve timing to be altered."

Post 1 - Bugatti T72 Bicycle Engine

c. 1941
10.5cc
Single air-cooled cylinder
Twin overhead cams
Supercharged
Capable of at least 10,000 RPM
Power unspecified
Less than 10 built

Information and photos from DucCutters