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 specifications and performance data.
| Identifier | ExFiles\Box 24\5\ Scan337 | |
| Date | 24th September 1930 guessed | |
| DESCRIPTION OF RADIATOR TUBE. NO. OF TUBES SURFACE OF TUBES IN CONTACT WITH AIR. SQ. FT. FREE AIR AREA RADIATOR TUBES. SQ. INS. % FREE AIR AREA RADIATOR. % DIRECT COOLING. SQ. FT. SURFACE PER SQ. FT. FRONTAL AREA DIFFERENCE IN TEMPERATURE BETWEEN TOP WATER TEMP. & ATS. TO DISSIPATE ENGINE HEAT AT 60 M.P.H. NO BONNET VENT. 6/7 & 1/2 m.m. round tubes. | 8115 | A.{Mr Adams} 164 | 314 | 50.5% | 84.4 | 37.9 | 63.5 5 & 1/2 /7 m.m. round tubes. | 8991 | 163.5 | 282 | 45.3% | 84.35 | 37.6 | 60.5 6/7 m.m. round tubes. | 8991 | 180 | 349 | 54.2% | 84.7 | 41.6 | 57.0 6/7 m.m. square tube. 1 m.m. strip between each tube. | 7050 | 178 | 348 | 54.1% | 84.5 | 41.2 | 61 6 m.m. parallel square tube. | 8860 | 218.5 | 436 | NOW BEING MADE. 70% | 46.2 | 50.6 | 49 .5 m.m. parallel square tube | 10045 | 235 | 426 | EFFECT OF TUBE SIZE. 68% | 46.6 | 54.3 | 43 FIGURES FOR RAD. MATRIX 26" HIGH 24" WIDE. COLUMN A.{Mr Adams} FROM TESTS SHEWS APPROX. RELATIVE RADIATOR EFFICIENCY. | ||