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).
'EAC' over-oiling and the effectiveness of scraper ring bevel orientation.
| Identifier | ExFiles\Box 72\1\ scan0001 | |
| Date | 1st February 1925 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. 48980 REF. HS{Lord Ernest Hives - Chair}4/LG27. 2. 25. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} S E C R E T. 'EAC' OVER-OILING. [strikethrough]X 8050[/strikethrough] We have found on some of the EAC. cars that the excess oil consumption has been caused by oil working down passed the inlet valve stems. The pressure of the low pressure oil varies considerably with the speed, and at high engine speeds, a considerable amount of oil runs from the rockers into the recess of the valve spring washer, through the slots of the taper wedges and so down the valve stems. Immediately the throttle is shut, this is drawn through into the cylinders. We are arranging to reduce the pressure of the low pressure oil. With reference to scraper rings. We have, on a number of occasions, proved that we get less oil working passed the pistons if we have the bevel edge on the lower side of the scraper ring, than we do if we turn it the other way up, which at first sight, would appear the obvious way to have the bevel. Our tests have been carried out on the 40/50., 20 HP., Condor, and EAC. The results have [redacted] consistently shewn the bevel at the bottom to be most effective. Attached is a possible explanation by Mr. Lovesey why this occurs. Hs.{Lord Ernest Hives - Chair} | ||