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).
Report comparing cooling standards and test results with those of General Motors and Vauxhall.
| Identifier | ExFiles\Box 131\5\ scan0030 | |
| Date | 24th November 1937 | |
| -3- (4) With regard to other peoples' standards of cooling, the writer was informed by The Harrison Radiator Corporation (who deal with the cooling systems of the whole of General Motors Corporation in U.S.A.) that they consider the standard of cooling adequate if a car can be driven at full throttle at 20 m.p.h. and 60 m.p.h. respectively with a critical air temp. of not less than 40°C - 42°C (104°F.{Mr Friese} to 107.6°F) under either of these speed conditions. Examination of Sheet (3) shows that the Wraith car is adequately cooled by these standards - the 'minimum alteration' specification just about satisfied the above requirements while the 'optimum specific-ation' is above the standard set. Messrs Vauxhall's representative, Mr.Larking, informed the writer during a recent visit to Luton, that their criterion of adequate cooling was a critical air temperature of not less than 40.5°C. (105°F.{Mr Friese}) under any of the following conditions:- (a) 5.M.P.H. full throttle 1st. gear. (b) 10 M.P.H. full throttle 2nd. gear. (c) 15 M.P.H. " " 3rd. " (d) 20 M.P.H. " " top " He stated that these cooling standards applied to both their passenger and commercial vehicles. Examination of Sheet (3) indicates that with the 'optimum' specification, the Wraith car cooling is above the Vauxhall standard under 15 M.P.H. 3rd. gear and 20 M.P.H. top gear conditions, but the discrepancy between their quoted figure of 40.5°C. for 5 M.P.H. first gear and our corresponding figure of 21°C. is so great that we are sceptical as to whether they really attain this first gear figure. In any case the condition is an entirely artificial one for a passenger vehicle and one which we cannot conceive occurring on a passenger car. (It necessitates continuous full throttle running at 5.M.P.H. on bottom gear). No test was made in 2nd. gear. Result (3) on Sheet (3) indicates that full throttle running over a 10 miles stretch of excellent road (but not a dead straight permitting continuous max. speed) does not give as severe a test as Brooklands, the critical air temp. being about 5°C. higher than the corresponding Brooklands figure - in this respect it agrees roughly with similar tests on Ph.III. Further the road test is not suitable for detecting small effects on the car's cooling owing to the fact that conditions cannot be maintained constant enough - this test, however, is quite capable of being used for estimating effects of relatively large alterations to the cooling system and also for obtaining comparative values of other cars' cooling systems. continued | ||