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).
Increase of oil sump capacity for the 20/25 & J.3 models.
| Identifier | ExFiles\Box 103\2\ scan0242 | |
| Date | 25th April 1931 | |
| COPY. SG{Arthur F. Sidgreaves - MD} from E.{Mr Elliott - Chief Engineer} Secret. E1/M25.4.31 20/25 & J.3. OIL SUMP CAPACITY. Referring to SG{Arthur F. Sidgreaves - MD}7/E23431 we are definitely in favour of carrying more oil in the engine and we should like to have two gallons in Japan 3. Unfortunately the conditions imposed by a low transmission line, adequate ground clearance and longer stroke restricted the oil space to 1.5 gals. on this engine, but we shall make a further attempt to reach 2 gals. We do not agree that the oil requires completely renewing on the 20/25, but we can well understand that on long fast runs in France the oil requires topping up daily and that more reserve oil would be an advantage. On the old 20 HP. RR. the maximum oil capacity was 1 gal. and the dial was marked in such a way as to indicate that .75 was the normal quantity. On the 20/25 there is no encouragement to restrict the oil to .75 but the maximum marking is still 1 gal. We have made an investigation and believe that the 20/25 oil can be increased to at least 1.25 gals. with a possible maximum of 1.5 gals., taking a little more risk, as we do now-a-days, with the end big ends dipping on gradients. No alteration beyond an extension of the gauge reading would be required but we should ask HS.{Lord Ernest Hives - Chair} to confirm the figures experimentally. E.{Mr Elliott - Chief Engineer} | ||