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).
Piston knock issues, lubrication improvements, and the use of castor oil.
| Identifier | ExFiles\Box 181\M11\ img209 | |
| Date | 5th September 1919 | |
| 40/80 To Mr. from R.{Sir Henry Royce} Copy to C.H. B.M. D.A. E.F.C. ORIGINAL D X.2448 RE PISTON KNOCKS. X.1434 STAMP: 5th SEP 1919 REC'D Thank you for your memo EH4/LG29/8/19 with reference to piston knocks. I am pleased to hear that considerable progress has been made in finding the cause of variation from one piston to another. I do not think for a minute that we can purposely upset the alignment to reduce the tendency to knock. I have much more faith in the general design of the piston and the method of lubrication. I am very pleased to hear that castor oil and the continued action of the cylinder lubrication, even at light loads, is a distinct improvement. I am sure that with this extra quality and quantity of lubrication, both the engine and the pistons will wear better. The extra cost of the oil is very little indeed considering how little the engine consumes, and I shall be pleased if you will let me know the relative cost of the Vacuum Company's oil, and castrol, at such prices as they would be supplied to the car owner. In conclusion, the next car put on a long test should be run with castrol and castor oil, whichever you recommend should be used by the owners, there being just the possibility that these oils may not remain in condition long enough in the crankchamber, considering the great number of miles we can run the engine on a single charge of oil. In future I am looking into the possibilities of entirely draining the crankcase more easily. R.{Sir Henry Royce} | ||