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).
Comparative analysis of the cooling performance of Hispano and 40/50 HP fans and cooling systems.
| Identifier | ExFiles\Box 38\2\ Scan268 | |
| Date | 25th November 1924 guessed | |
| SHEET 3. RELATIVE VALUE OF HISPANO AND 40/50 FANS. 30 M.P.H. CAR DETAILS. | δt | % difference from 'Ad. | Critical ats. temperature. 40/50 HP. 20¾" matrix. Louvres. | 70.5°C | 'A' | 24.5°C Ditto - no Fan. | 91.5°C | 30% worse. | 3.5°C Hispano - louvred bonnet. | 60.7°C | 'A' | 34.3°C " - No fan. | 66.8°C | 10% worse. | 28.2°C RELATIVE EFFICIENCY OF HISPANO AND 40/50 COOLING SYSTEMS. 40/50 HP. 21¼" matrix. Louvres - 30 M.P.H. | 68.2°C | 'A' | 26.8°C Ditto - 20 M.P.H. | 73.6°C | 8% worse | 21.4°C Hispano - Louvres. 30 M.P.H. | 60.7°C | 11% better. | 34.3°C Ditto - 20 M.P.H. | 61.2°C | 10.2% better. | 33.6°C | ||