Secret memorandum discussing car radiator and fan design improvements to prevent overheating.
| Identifier | WestWitteringFiles\L\2July1924-September1924\ Scan82 | |
| Date | 1st August 1924 | |
| TO RG. {Mr Rowledge} } FROM R. {Sir Henry Royce} HS. {Lord Ernest Hives - Chair} } SECRET. *OVERHEATING R1/M29. 8.24. Copy to CJ. BJ. " " DA. {Bernard Day - Chassis Design} H. {Arthur M. Hanbury - Head Complaints} " " BY. {R.W. Bailey - Chief Engineer} EP. {G. Eric Platford - Chief Quality Engineer} re. VISIT OF RG. {Mr Rowledge} & HS. {Lord Ernest Hives - Chair} TO WW. ON 27th & 28th inst. X766 X3438 X3456 X4214 X9250 X4240 CAR RADIATORS. From figures the 20.HP. has ample size and effic-ient fan, and should be O.K. Compared with the Hispano the big 40/50. engine heats a lot of water. Our radiator face area is propor-tionately smaller, and as regards natural air currents - independent of fan - it is worse than Hispano, but with a more efficient fan makes us superior. What can be done. - Both our 20.HP. and 40/50 cars can have louvred bonnets; (which we think a decided advantage, and very generally fitted to all other large cars) to partly meet the complaint, but as these have the disadvantage of noise, and appearance, we do not propose to fit them as standard. The 20.HP. should have no other changes made unless we can find a better scheme. Two years ago the 40/50 had a 19" matrix (height.) At present it is 20". We are arranging for this to be 23", and the fan also will be increased in diameter and greater freedom for the escape of the heated air has been arranged. Greater size than this 23" matrix would drive us into difficulty and to go down would force us to adopt complex and costly construction, while to go up we should get German appearance, and would make it difficult to see if the front wing would clear near objects. The width is at present great, and up to the full limit. FAN. (SIZE & SPEED.) With the larger matrix the fan will be increased in diameter, but owing to noise and slipping belt we do not propose to alter the standard speed which is already fast, being 1 1/4 times engine speed. DESIGN OF FAN. I propose that the Aircraft people be asked if they could suggest a better design of a 2, 3, 4, or 6 bladed fan, either one that will increase the air circulation, or for equal circulation, one that would be easier to drive. In my remarks on radiators it should be understood that not one car in 500 is satisfactory under full throttle, low speed, and hot weather, and the larger the engine the greater the deficit. Careful comparison will be made. Reports are not to be relied upon. (1) | ||
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).