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 cooling performance between Hispano and 40/50 fans and systems.
| Identifier | ExFiles\Box 24\4\ Scan306 | |
| Date | 25th November 1924 guessed | |
| SHEET 3. RELATIVE VALUE OF HISPANO AND 40/50 FANS. 30 M.P.H. CAR DETAILS. S°C % difference from 'A&A'. Critical ats. temperature. 40/50 HP. 20 1/4" 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. 21 1/4" 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°E 10.2% better. 33.6°C | ||