Test data tables on the cooling efficiency of a 40/50 HP engine, examining the effects of speed, matrix/shutter configuration, and fuel mixture strength.
| Identifier | ExFiles\Box 22\1\ Scan221 | |
| Date | 17th February 1925 guessed | |
| INCREASE IN EFFICIENCY OF 40/50 HP. COOLING SYSTEM WITH SPEED. SHEET 4. 20¾" matrix. Road speed. | δt | % difference from 'A'. | Critical atmospheric temperature. 20 M.P.H. - all closed. | 82.2ºC | 'A' | 11.8ºC 30 M.P.H. - " " | 77ºC | 7.5% better. | 18ºC 40 M.P.H. - " " | 71.6ºC | 14% better | 23.4ºC 40/50 HP. WITH 22¾" 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. 22¾" Matrix. 4 large shutters. Total area 112 sq.in. | 62ºC | 'A' | 33ºC Hispano - louvres. | 60.7ºC | 2.1% better. | 34.3ºC AFFECT OF MIXTURE STRENGTH - HISPANO - 30 M.P.H. Std. rad. conditions. Mixture control. | δt | % difference from 'A'. | Critical ats: temperature. Strong mixture. | 58ºC | 'A' | 37ºC Weak mixture. | 63.4ºC | 9.3% worse. | 31.6ºC Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} | ||
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).