From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Comparison of 'High Power' and 'Chevrolet' cylinder heads, showing valve sizes and cross-sectional diagrams.
| Identifier | ExFiles\Box 134\2\ scan0067 | |
| Date | 11th July 1938 | |
| High Power Head FIG. II COMPARISON OF HIGH POWER AND CHEVROLET HEADS VALVE SIZES CHEV. HIGH POWER INLET 1.15" 1.75" EXHAUST 1.25" 1.50" CHEVROLET INLET EXHAUST HIGH POWER ALTERNATIVE PLUG POSITION INLET EXHAUST J.L.E. 11.7.38 | ||