| Year | 1930 |
| Date | 19-Jun |
| Volume | 62 |
| Issue | 1,519 |
| Page | 582 |
| Category | Petrol Engine Topics |
| Part | |
| Title | Petrol Engine Topics |
| Author | Edgar T.Westbury |
| Notes | Valve timing, the reason for overlap, timing digaram of 30 c.c. engine, considerations in model engines, engines without overlap, r.p.m. and piston speed |