Patent Garabello engine.
In Fig. 2 AND 3 you can see the diagram of the rotary valve. Both the inlet and exhaust are axial (with a larger diameter for the exhaust). The top tube on the diagonal is the lubrication. You can see the system of stamps with springs, intended to control the tightness of both the combustion chamber as the system of lubrication.

Courtesy Sergio Scalerandi
Garabello Motorcycles