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).
New crankcase breather scheme (LeC.5067) for the Phantom III, designed to reduce oil loss at high speeds.
| Identifier | ExFiles\Box 132\3\ scan0052 | |
| Date | 22th April 1936 | |
| X 316 To E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} c. to Mx.{John H Maddocks - Chief Proving Officer} Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}22/KW.22.4.36. Phantom III Crankcase Breather. Trouble has been experienced in that when running at high speeds, 4250 r.p.m. - 4500 r.p.m., a considerable quantity of oil comes down the crankcase breather pipe, a flow taken at 4500 r.p.m. registering a loss of 30 pts/hr. In comparison, the scheme LeC.5067 incorporating an oil separator box with baffles and return oil drain via the oil level indicator into the sump, has been tested on the unit bed, resulting in almost a complete cure of the job. The actual improvement is from 30 pts/hr down to an occasional spot of oil when running at 4500 r.p.m. with the oil temperature at 90°C. Running at this speed the scheme results in an increased crankcase back pressure from 2.2 ins H2O to 3.3 ins. H2O. This test can only be regarded as a comparison between the two schemes and not as true figures for when under car conditions and running at high speeds there may be some extractor action creating a suction on the vent pipe. We are instructing that this scheme be tried as soon as possible on the road as a final test. Hs{Lord Ernest Hives - Chair}/L.H.Swindall. | ||