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).
Technical note on engine overoiling, proposing a different method of feeding oil to the crankshaft to ensure proper lubrication.
| Identifier | ExFiles\Box 16\1\ Scan079 | |
| Date | 14th February 1915 | |
| EXTRACT OF PEAT'S LETTER R.R.-93940 (S.A. 383. 4-3-15) C. 0970. DATED 14/2/15. "Thinking over the question of overoiling engines it occurs to me that a strong case can be made out for a different method of feeding the oil supply to the crankshaft of our engines. As fed at present a fairly high pressure must be maintained to ensure oil reaching the small main bearings (4), and the big ends of Nos 2 & 5 connecting rods at the times when the engine speeds are sufficiently high to set up a centrifugal force which by greatly increasing the pressures at which the oil reaches connecting rod bearings 1&3 or 4&6 causes so much oil to leave these bearings that there is a little or none left for the small intermediate main bearings and even less for the Conn.Rod bearings Nos. 2&5. It must be remembered that what oil is available for these bearings has at very high speeds to travel along its passage in the crank web AGAINST a very considerable centrifugal force which is constantly trying to force it back again to the Conn rod bearings (Nos.1.3.4.&6.), which it is endeavouring to leave thus still further increasing the pressure and therefore the amount of oil lost at these bearings. If oil were fed to every main bearing centrifugal force, which at present is a hindrance to our oiling system would it self ensure that oil would reach all bearings whatever at any speed whatever and this would be infallible at even very low oil pressures. For this reason, although our present oil pressure of about 15 lbs could still be adopted as our standard or normal oil pressure YET it would be possible and quite safe to reduce this pressure to 3 or 4 lbs. in the case of an overoiling engine without any risk of seizing or damaging any part of the engine. At present Nos.2&5 big ends are absolutely at the mercy as it were of any of the | ||