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 results on B.60 oil pumps regarding improved oil pressure at idling speed by reducing gear clearance.
| Identifier | ExFiles\Box 124\2\ scan0317 | |
| Date | 1st July 1941 | |
| 1094 To Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager} c. to Rm{William Robotham - Chief Engineer}/JNR.{Charles L. Jenner} c. to Rm{William Robotham - Chief Engineer}/OFS. SECRET. Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager}S/JH.1.7.41. In reply to memo. Jnr.{Charles L. Jenner}7/SW.13.5.41. we have now obtained some figures on B.60 Oil Pumps, which show that with reduced end clearance of the gears in the casing we can get a much improved oil pressure reading at engine idling speed. By reducing the end float of the gears from .0065" to .0025 we get an increase in oil pressure at idling speeds from 2,3 lbs. to 9 - 10 lbs.sq.in. The following tables give the results of our tests :- lbs.insq. lbs.in.sq. SPEED. Oil Temp Max. Oil Pressure. Min. Oil Pressure A B C. A B C A B C 80 mph. 82oC. 82oC. 88oC. 38 40 40 2to3 9to10 7to8. 70 " " 88o 36 39.5 39 " " " 60 " " 90 35 39 38 " " " 50 " " 90 32 36 36 " " " 40 " " 90 29 32 32 " " " Details of pump. A.{Mr Adams} End float of gears, including .002" thickness of packing = .0065". Radial clearance of gears .002". B. As A but .004". C. As A - .0025". The paper packing between the casing faces compresses to .002". We would suggest a working end clearance on the gears of .0005" to .0015" which together with the .002" clearance created by the packing would give a total end clearance of .0025" to .0035". We have not yet been able to do any experiments with the drilled up camshaft as this necessitates dismantling an engine. Rm{William Robotham - Chief Engineer}/wym.{G. Harold Whyman - Experimental Manager} | ||