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).
List of recommendations to improve engine bore wear, followed by a note on oil consumption tests.
| Identifier | ExFiles\Box 132\4\ scan0095 | |
| Date | 19th October 1937 | |
| -3- Rm{William Robotham - Chief Engineer}/Mths.{Reg Matthews}8/WR.19.10.37. Recommendations to improve bore wear. (a) Increased oil supply at low speeds, whilst maintaining present supply at high speeds. (b) Addition of chromium in the iron up to approx. 0.3% (c) Reduction in the amount of Nickel to the lowest possible requirements consistent with foundry experience and the addition of Chromium as above. The addition of the 1% to 1.5% of nickel at present used, represents approximately 40% of the total cost of the iron. (d) Lowest ring pressures we can use consistent with the requirements for good oil consumption. (e) Better crankcase ventilation. (f) Individually cast rings both from cost and more uniform hardness point of view. (g) Thermostatically controlled cooling of water by by-pass type of thermostat. (h) All pearlitic structure of cylinder material. (j) Ring hardness slightly higher than cylinder hardness. (k) As high a percentage of Phosphorus as is desirable for foundry requirements. (l) Combined carbon should be approximately 0.5% to 0.7% The Midland Cylinder Co's specification approximates very closely to our requirements and showed good wearing properties on 15,000 miles test. Oil Consumptions. In our tests on oil consumption various ring arrangements were tried and Fig.1 shows the results obtained with the standard ring arrangement, and with standard rings using stops, in the | ||