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).
Radiator design alternatives, materials, performance issues, and testing requirements.
| Identifier | ExFiles\Box 38\2\ Scan017 | |
| Date | 18th December 1918 | |
| -3- R7/G181218. Contd. Mr. Johnson's and Sales' approval of the radiator as it will appear with this tank will be required. The difficulty will probably be in connection with this matter, to obtain flat surfaces. Material of 16 SWG should be tried, and if this is successful, try also a lighter gauge. The alternative method is to construct the tank from flat sheets as at present, but using brass angles in the corners, (as shewn on some early LeC. drawing) instead of the wire with heavy fillet of solder. A bonded round tube radiator cannot be made without loss of efficiency, as its arrangement necessitates large water spaces and a smaller number of tubes. There seems to be a distinct tendency to have the radiator too large, so that the engine is much too cool with consequent bad effects on the carburation. It is not possible to make the radiator to suit all climates, and we should endeavour to keep the size of the radiator down for English models. It has always been found necessary to block out in the Winter, a very large portion of the radiator on the car used by Mr. Royce, to get the engine in a reasonably warm state. Radiators ought not to weigh more than 80 lbs. The whole of the draughting work required by the above should be carried out by Mr. Bailey and the designs should be submitted for Mr. Royce's approval before ordering the radiators. X.3456D A fourth radiator should be added to the list, made with a bonded square tube matrix, as in radiator No.(3) but with the bonding wires vertical and horizontal. The square tubes to be used for radiators (3) and (4) should have large radii in the corners so that any small variations of this dimension will not have the effect of spoiling the metal in the corners. It was at first not desired to test any radiators with smaller tubes than those specified, but Mr. Royce has since pointed out that the small tube matrix may be stronger than the larger tube matrix in resistance to bumping, and that therefore a test to determine this point should be made. A fifth radiator built with small tubes must therefore be added to the list. X.3456E This latter instruction supercedes Mr. Royce's memo R2/G4119 to Mr. Bailey. | ||