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).
Cold chamber starting tests for Phantom III, 25/30, and Bentley models using various oils.
| Identifier | ExFiles\Box 151\3\ scan0336 | |
| Date | 10th December 1937 | |
| To Rm. {William Robotham - Chief Engineer} from Rm {William Robotham - Chief Engineer} /FD. {Frank Dodd - Bodies} Rm {William Robotham - Chief Engineer} /FD. {Frank Dodd - Bodies} 3/MH. {M. Huckerby} 10.12.37. PHANTOM III COLD CHAMBER TESTS. Attached is a report on the starting of a production P.III chassis fitted with hydraulic tappets. Results show a very unsatisfactory start with a sump oil temperature of only 29°F, engine R.P.M. was 45. Attached is also a report on the starting of 37-EX with fixed tappet mechanism. It will be seen from these figures that at the same sump temperature of 29°F the engine R.P.M. are approximately the same on the two cars, yet the starting is not comparable, 37-EX starting at the second effort with the starter and continuing to run evenly on all cylinders. Mobiloil arctic was used in both cases. A test was also made on 37-EX with Castrol XL Summer oil and the results were very good, the engine starting at the fourth attempt and running evenly after 10 secs., oil temperature 14°F, (figures on attached sheet). 25/30 COLD CHAMBER TESTS. There should be no difficulty in starting a 25/30 using winter grade oil, down to 8°F. {Mr Friese} oil temperature, a quick start can be made down to 23°F oil temperature on summer oil Castrol XL, the figures are attached. BENTLEY COLD CHAMBER TESTS. 5.B.4. UNIT B.16 AEROLITE PISTONS. Attached are the results of starting tests on various grades of Winter oil, the following makes were tested:- Mobiloil Arctic, Castrol CW, Castrol AA {D. Abbot Anderson} , Shell Light and Duckham's N.P.XX. Our tests show that Mobiloil Arctic is the best oil for easy starting, and that we should never have any starting trouble on the Bentley even under extreme conditions, down to | ||