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).
The oil consumption of the 25/30 HP engine, detailing the risk of piston seizures if consumption is too low.
| Identifier | ExFiles\Box 144\3\ scan0078 | |
| Date | 9th July 1936 | |
| W/S - C. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}8/KW.9.7.36. Oil Consumption - 25/30 HP. C5/C.3.7.36. We fully appreciate the undesirable condition of the 25/30 with regard to oil consumption as at present being delivered to customers. Since the trouble became manifest we have been running continuous experiments to determine what is the best move to make to put cars right. As you will appreciate, if the oil consumption of an engine is too good we get piston seizures. It is therefore not a matter of making the oil consumption as good as we know how, but of making sure that any improvements we effect do not bring up piston trouble. The Daily Report of July 7th on the big bore 25/30 running in France gives 1200 miles to the gallon, this engine unit having done over 10,000 miles. If we get a much lower oil consumption than this at average speeds of over 40 M.P.H., we shall get piston seizures. However, something can be done and we expect to make some recommendations next week. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||