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).
Comparing the performance and merits of the Clayton Still oil cooler versus the Buick type cooler.
| Identifier | ExFiles\Box 131\1\ scan0102 | |
| Date | 23th May 1933 | |
| XV693. To Sg.{Arthur F. Sidgreaves - MD} From Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} C. Mor. E.{Mr Elliott - Chief Engineer} C. Ds. Hy.{Tom Haldenby - Plant Engineer} C. EV.{Ivan Evernden - coachwork} Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}3/RT. 23.5.33. ----------------- OIL COOLERS. We have carried out tests of the relative merits of the Clayton Still oil cooler to L.C.3431. fitted to 3.Per.II. and the Buick type cooler Ex.10987 fitted to 4.Per.II. We attach a chart of temperatures attained by the water and oil while driving continuously full throttle round Brooklands. With the Buick cooler, the shutters fully open, the oil never exceeded 73ºC. With a water temperature of 65ºC. If the shutters were working at 80ºC, we should expect the oil to reach 85ºC, although under these conditions on the track 85ºC. was never exceeded. At the end of four laps the oil cooler short circuited, the oil temperature rose from 30ºC. to over 100ºC. We attach a further sketch of the time taken to warm the oil from a cold engine, the engine ticking over at 900 r.p.m. It will be seen that the Buick type cooler has warmed the oil to 50ºC by the time the water reaches 70ºC. No such benefit is obtained from the Clayton cooler. As we have deleted the extra oiling scheme, we consider that rapid warming of the oil is the best way to minimise cylinder wear, the chief cause of which is driving a car with cold oil and hence insufficient lubrication to the pistons. Both coolers extract about 200 B.T.U's/min. from the oil, the Clayton by impairing the efficiency of the radiator 18%; and the water cooler about 6½%. Further, although it is a matter of opinion, we do not like the idea of oil pipes continually subjected to torsion leading to the cooler in the radiator. Failure of one of these would mean losing all the oil with possible consequent damage to the engine. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||