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).
Reducing engine oil consumption and smoke by fitting 'L' shaped piston rings.
| Identifier | ExFiles\Box 66\1\ scan0022 | |
| Date | 18th March 1925 | |
| R.R. 493A (50n) (D.B. 175 25-9-24) J.H.D. X8040 EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}5/LG18.3.25. 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. X8040 X8980 EAC+ 'V' SERIES - OIL CONSUMPTION. We have confirmed on three separate EAC. engines that we can reduce the consumption so that at any speed it comes below 1 pt. per hr. when we fit the 'L' section rings. We have also tried similar rings on a 20 HP. engine which had a complaint of smoking very badly after running light for a short time. Modifying the rings on the 20 HP. pistons reduced the amount of smoke 75%. Although we have confirmed that the 'L' shaped rings reduce the consumption, we are not certain that the reason they do this is because of the scraper effect. At the present time we are carrying out tests to prove whether it may not be gas pressure at the back of the ring which is making the rings more effective as regards scraping the oil off. The pistons with the groove below each ring were improved by fitting the 'L' shaped rings. Hs.{Lord Ernest Hives - Chair} Photostats not sent out | ||