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).
Relative merits and designs of water-based and air-based oil coolers for various engines.
| Identifier | ExFiles\Box 131\1\ scan0121 | |
| Date | 16th June 1933 | |
| XH692 To Sg.{Arthur F. Sidgreaves - MD} from E.{Mr Elliott - Chief Engineer} c. Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Da.{Bernard Day - Chassis Design} EV.{Ivan Evernden - coachwork} E.7/HP.16.6.33. Oil Coolers. Referring to your memo Sg.{Arthur F. Sidgreaves - MD}3/E.13.6.33, we certainly agree that on the results of our experiments with the Buick water and Clayton Still air oil coolers, the former is the more desirable scheme. Air cooling for the oil is very successful on the Light Tank installations where the oil temperature is kept below that of the water. We particularly value, however, for car work the feature on the water cooler of the oil being warmed up rapidly by the water. A disadvantage of the Buick scheme not mentioned in the report is a possible failure of the matrix causing the loss of all the oil into the water system and incurring the risk of damaging the engine. In this respect we should propose to make sure that the design used would be mechanically strong. We are still somewhat mystified as to why our Peregrine developing 70 B HP. needs an oil cooler, and the 20/25 developing the same power does not. Also why the J.III developing 115 B.HP. needs an oil cooler and the Bensport with the same output does not. The wheelcase and gears at the front end of the engine have been suggested as contributing to the oil cooling effect on 20/25 and Bensport, but tests only show a small percentage of difference on this point. We shall soon, however, have a similar condition on J.3. We know that a certain amount of heat is being passed to the oil via. the flow through the camshaft case on Peregrine, but again this will be washed out on the revised J.3. with engine gears at the front. | ||