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).
Engine oil temperatures, bearing leakage, and flywheel balance tests.
| Identifier | ExFiles\Box 83\1\ scan0206 | |
| Date | 21th September 1936 | |
| x200 a copy sent to all Testers GWH{George W. Hancock - Head Chateauroux}/ HOTEL DE FRANCE, CHATEAUROUX, Indre. France. To. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} C. G.W.H. GWH{George W. Hancock - Head Chateauroux}/IMW{Ivan M. Waller - Head of Chateauroux}/2/JAB. 21st September 1936. 6. B. IV. Re memo. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}2/KW.19.9.36 Thank you for your memo re oil temperatures. The main oil pipes are not interchangeable with any existing pipes on account of the pressure oil filter. Perhaps you could let us have a pipe fitted with a thermometer pocket suitable for this job. The pressure test which you recommend for ascertaining the leakage from the main bearings was carried out when the new con-rods were fitted. There was more leakage from the last three main bearings than the others; N° 7 was the worst. This would contribute towards the big end failure. Oil is now leaking from the rear main bearing into the clutch housing, and is finding its way on to the new clutch linings. We have measured the lift on the flywheels of both cars by means of feelers between the clutch & the pointer. 22.G.V. is .004" and 6.B.IV. is .020". We have endeavoured to improve the balance by means of steel strips under the nuts attaching the clutch to the flywheel. Weights equal to four 3/8" full nuts added level with the BDC mark seem to effect the best improvement with the engine running light. We shall have the gearbox back and the car running again to-morrow and will report if there is any improvement on the road. Observation has shown that for any given engine, oil temperature is determined only by the revs maintained (the only external factor that makes any difference is water splashed onto the sump from wet roads). On these engines, the approximate temperature is 110°c at 4,000 revs.p.m. and above this from 120° up to 135°c at maximum revs. We attribute the bearing failure to high bearing loads and excessive oil temperatures. These are due to high engine revs. These in turn are due to a top gear that is too low for the conditions under which the car is driven. ---------------- P.S. In your memo we have interpreted "N°6 bearing" to mean "N°7 main bearing". Please confirm this. GWH{George W. Hancock - Head Chateauroux}/IMW.{Ivan M. Waller - Head of Chateauroux} Ivan M.{Mr Moon / Mr Moore} Waller. | ||