3.01 – 100 HP Gnome Monosoupape Rotary Engine – Rocker / Valve Gear

Rocker / Valve assembly

Having purchased a digital copy of the original engine’s service manual:

The Care of the 100 h.p. Monosoupape Engine


Vendor : Weak Force Press (Huntsville, Alabama, USA)

Photos and Drawings

This manual provided a wealth of information on the major components and a crucial cross sectional view of the rocker / valve gear.


Components are rotated in this cross-sectional view for drawing convenience.

Using a combination of photos and cross sectional information, I have been able to rebuild the piston assembly, making it more representative of the original engine.

Fusion 360 – Screenshot


This was a great modelling challenge – and a compromise between actual design and originating a form that could be 3D printed in manageable sections and assembled at a later date.

More to follow…