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).
Report page detailing engine testing results, specifically regarding oil flow, lubrication, and the performance of piston rings.
| Identifier | ExFiles\Box 182\M18\ img085 | |
| Date | 26th December 1922 guessed | |
| contd :- -5- This engine has been tested at full load 2750 r.p.m. on the bench and ran perfectly well without any signs of drainage of oil to pistons. When shut down it was quite free to turn over by hand and examination of the cylinder bores showed even lubrication without excess. This seems proof that oil flow as low as B.H.P is quite sufficient and reliable for successful operation of the engine. PISTON RINGS. We have demonstrated that rings exert an influence upon over-oiling the worst offenders being those which are free, i.e. possess up and down movement, in the grooves as they seem to have a pumping action on the oil. 'L' section rings are excellent when new but even with an engine having excessive oil flow will usually correct over-oiling only unfortunately their high efficiency rapidly diminishes as would be expected, with wear. When their efficiency reaches a minimum constant value they should still be equal to plain rings or even superior to new plain rings because they would have 'lapped' themselves to the cylinder bores. Therefore from consideration of the above we see no reason why 'L' section rings should not be employed. There are various other factors exerting slight, but unappreciable, influence on oil consumption, such as pistons - see previous reports. It should be mentioned in passing that we have met with no success by employing various forms of oil baffles. Numerous types have been tested but not a single one has lessened the over- contd :- | ||