| Year | 1933 |
| Date | 21-Dec |
| Volume | 69 |
| Issue | 1,702 |
| Page | 593 |
| Category | New Tools and Supplies |
| Part | |
| Title | New "Wall" Petrol Engines and Accessories (Elmer A.Wall) |
| Author | |
| Notes | "Question Mark" air-cooled four-cycle engine, the "Wizard" flat twin, the "Featherweight" two-cycle model aircraft engine, new four-cylinder experimental engine |