Wagner made an engine to be  installed on the rotor head of a helicopter.

“Wagner engine on a rotor”

-The engine has four cylinders in a horizontal star shape. It runs diesel fuel. It delivers 85 hp.

“Cross-section of a cylinder”

-The helicopter's blades extend from the cylinder head, reminding us of the Anita engine (see).

From Appendix 6: The four-cylinder engine mentioned in the main text, of which there are some sketchy illustrations, can now be seen in a photo taken at the German Helicopter Museum.

-This is the Wagner rotary engine installed on the Rotocar helicopter. Two blades extend from the two-cylinder cylinder head. The other two blades are above.

“Engine detail”

From Appendix 10: Diesel engine installed under the rotor of a helicopter. See description in the main text. Here is a new, slightly more detailed photograph.

"Wagner Diesel Engine on a Helicopter"