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).
Performance data for a 40/50 HP engine cooling system, showing the effects of speed, ventilation, and fuel mixture.
| Identifier | ExFiles\Box 38\2\ Scan269 | |
| Date | 23th March 1921 guessed | |
| SHEET 4. INCREASE IN EFFICIENCY OF 40/50 HP COOLING SYSTEM WITH SPEED. 20¼" matrix. Road speed. | δt | % difference from 'A'. | Critical atmospheric temperature. 20 M.P.H. - all closed. | 82.2°C | 'A' | 11.8°C 30 M.P.H. - " " | 77°C | 7.5% better. | 18°C 40 M.P.H. - " " | 71.6°C | 14% better | 23.4°C 40/50 HP. WITH 22¼" MATRIX AND LARGE SHUTTERS OPEN COMPARED WITH STD. HISPANO CONDITION 30 MPH. Car and Ventilation details. | δt | % difference from 'A' | Critical atmospheric temperature. 40/50 HP. 22¼" Matrix. 4 large shutters. Total area 112 sq.in. | 62°C | 'A' | 33°C Hispano - louvres. | 60.7°C | 2.1% better. | 34.3°C AFFECT OF MIXTURE STRENGTH - HISPANO - 30 M.P.H. Std. rad. conditions. Mixture control. | δt | % difference from 'A'. | Critical ats: temperature. Strong mixture. | 58°C | 'A' | 37°C Weak mixture. | 63.4°C | 9.3% worse. | 31.6°C Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||