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).
Letter to W.L.P. Saunders discussing car heater design, thermostat noise, and oil cooler issues.
| Identifier | ExFiles\Box 149a\3\ scan0222 | |
| Date | 27th April 1958 | |
| M.L.P.Saunders. -2- 27th. April 1958. We have been taking a good deal of interest in car heating recently and have designed a combined heater and defroster to DCD.221 (print attached) - further we are now testing such a unit. Our main consideration is to keep the bulk of the job down as far as possible as we are very tied up for room when it comes to fitting a heater on our dashboard. Would be interested to know whether you have made any tests with a system of heating using fresh warm air drawn from the rear of the car's radiator matrix - we have made a few tests with such a system and find it very promising, but it has the objection that it is difficult to avoid noise transmission into the body. We have recently come up against a thermostat peculiarity through the agency of a car heater - the latter gave a peculiar "clicking" noise and this was traced to a water hammer effect caused by flutter of instability of the thermostat valve - this being due to the mean area of the bellows being considerably greater than that of the thermostat valve. Would like to know whether you have found the separate diaphragm type of bellows which you use in any way superior to the rolled bellows or hydraulically formed bellows construction which is general over here. Oil coolers continue to be a source of trouble with us - in spite of improved manufacture and detail improvement in design, we still get failures. Actually we shall dispense with the cooler on future cars in view of its unreliability - this is now permissible because of the use of aluminium-tin bearings. Would like to emphasize that it is a unique experience and a very pleasurable one to be writing to you without a list of urgent requests for information, and would also like to repeat my thanks for the mass of information which you have passed on to us from time to time. Best personal regards, Yours sincerely, | ||