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 table of radiator tube performance and specifications under various test conditions.
| Identifier | ExFiles\Box 29\3\ Scan292 | |
| Date | 14th October 1930 guessed | |
| FIGURES GIVEN ARE CRITICAL ATMOSPHERIC TEMPERATURES AT WHICH THE CAR WILL EVENTUALLY BOIL IF DRIVEN SUFFICIENTLY LONG. DETAILS OF RADIATOR. TABLE DATA: COLUMN HEADERS: TYPE OF RADIATOR TUBES. Temp. Centigrade tests. 60 M.P.H. NO BONNET VENTILATION ALL OUT NO BONNET VENTILATION. ALL OUT VERTICAL LOUVRED BONNET. RADIATOR LBS. WT. EMPTY. RADIATOR LBS. WT. FULL. NO. OF TUBES SQ. FT. SURFACE OF RADIATOR % DIRECT COOLING. ROW 1: Latest E.81385 5 m/m sq. parallel tubes. | 42 | 33 | 39.75 | 140 | 176+ | 8960 | 219.5 | 46.2 ROW 2: Standard 6/7 turbulent air flow tubes. | 39.5 | 30.5 | 39 | 120 | 168 | 8115 | 164 | 84.4 ROW 3: 6/7 exposed end sq. tube E.80239. | 37.75 | 29.0 | 36.75 | 138 | 173+ | 7080 | 178 | 84.5 ROW 4: 5½/7 round tubes E.79321. | 36.75 | 24.75 | 34.75 | 137.75 | 181 | 8931 | 163.5 | 84.3 ROW 5: Galley sig zag ribbon no indirect. | 34.5 | 26.0 | Not taken. | 114 | 154 | Not calculated. | Not specified | 84 ROW 6: Standard 6/7 tubes E.79449 | 34.25 | 21.75 | 32.25 | 120 | 168 | 8115 | 164 | 84.4 FOOTER: TESTS CONDUCTED ON 19-AX CAR ON BROOKLANDS TRACK. ALL RADIATOR MATRIX DIMENSIONS 25.9" x 23.7". CAR WEIGHT 49 CWT. AXLE RATIO 11 x 41. FOOTNOTE: + Solid vertical strips. Rolled vertical strips reduce radiator weight by 15-16 lbs. | ||