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).
Analysis of oil consumption issues, their causes such as leaking rockers, and potential remedies.
| Identifier | Morton\M18\ img086 | |
| Date | 26th June 1925 guessed | |
| contd :- -5- oiling tendency and in the majority of cases they have found to actually increase the consumption due to the suction past the baffles as the piston moves towards the end of its stroke. LEAKING INLET ROCKER MAY BE CAUSED BY OIL THROUGH THE VALVE GUIDES. The oil holes in the end of the inlet rockers were now plugged as it was found that if the inlet valve stem was slightly on the 'free' side in the guide, oil would be sucked down the stem into the induction pipe when running with small throttle openings. This produced smoking exhaust and fouled plugs. We also experience similar trouble with smoking exhausts with plain exhaust guides. The oil runs down the guides at low revs or when the engine stops. SUMMARY :- From consideration of the above results we find that :- (1) The rate of aggregate oil discharge through the bear- ings is one of the chief factors controlling oil consumption. By reducing the flow we can reduce the consumption. (2) 'L' section rings are excellent oil scrapers when new and when worn are as good as plain rings. (3) Oil flow can be reduced by (a) smaller bearing clear- ances (b) lower oil pressure. (4) Reduced bearing clearances better than a very low pressure. (5) A Phantom engine has run satisfactorily on the test bench with an oil flow of .7 pts/min. at 1000 r.p.m. Increasing contd :- | ||