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).
Test report on crankcase breather pressures with different configurations at various speeds.
| Identifier | ExFiles\Box 82\5\ scan0104 | |
| Date | 4th May 1937 | |
| 200a (3) HOTEL DE FRANCE. CHATEAUROUX. Indre. France. Rm{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux}/IMW{Ivan M. Waller - Head of Chateauroux}/5/JAB. 4th May 1937. To. Rm.{William Robotham - Chief Engineer} c.c. Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} 3. B. IV. Crankcase Breather. In continuation of our tests reported in Rm{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux}/IMW{Ivan M. Waller - Head of Chateauroux}/5/JAB 21st April 1937, we have carried out the following tests on crankcase pressures and also checked up on the final figures of the last test. There was no noticeable variation of pressure with opening and closing throttle. At no time during the tests was a depression recorded. I) With no breather at all. Rocker cover breather and oil filler both blanked off. Speed.................... 20 60 90 Pressure in inches of water............... 0.4 0.6 1.0 2) With open breather hole on side of oil filler. Rocker cover breather blanked off. Speed.................... 20 60 90 Pressure in inches of water............... 0.0 0.1 0.2 3) With breather pipe fitted to oil filler. Rocker cover breather blanked off. Speed.................... 20 60 90 Pressure in inches of water............... 0.1 0.4 0.4 This shows that the breather pipe on the oil filler, rather than act as an ejector is forming a slight obstruction. We tried removing the front engine shield to improve the flow of air past the pipe, but this made no difference. We are continuing our running with the rocker breather deleted, and will observe the effect on oil consumption and oil leaks with the 30 HP. type filler and breather. ----------------- Rm{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux}/IMW.{Ivan M. Waller - Head of Chateauroux} | ||