| Year | 1941 |
| Date | 15-May |
| Volume | 84 |
| Issue | 2,088 |
| Page | 395 |
| Category | Improving the Two-Stroke |
| Part | |
| Title | "Valves for the Valveless (Valves in two-stroke engines) |
| Author | Edgar T.Westbury |
| Notes | Rotary valves, scavenge valve of Sulzer oil engine, simple form applied to crankcase compression engines, use of a single valve to control admission and transfer, rotary transfer valves, typical timing diagram |