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 development of lubrication systems, comparing Kestrel and Merlin engine modifications.
| Identifier | ExFiles\Box 115\2\ scan0586 | |
| Date | 23th July 1940 | |
| Rm.{William Robotham - Chief Engineer}1/Dn.23.7.40. - 2 - During all these developments we retained a maximum oil pressure of 35 lbs. per square inch, since we found that raising the oil pressure usually affected the oil consumption, and also that it was not a permanent cure for failures after wear had taken place. The success of this logical development of an adequate lubrication system is emphasized by the fact that, since these alterations were incorporated in the power plant, we have been able to decrease the area of the big end by 15%, increase our specific output by 10%, and the present range of cars in the Experimental Department as fitted, have run 300,000 miles without failure, in spite of the fact that they have purposely been overdriven. For purposes of comparison, we attach print of the various modification systems which have been on production since the introduction of the Kestrel engine. Conditions have altered more gradually on the automobile than on the aviation power plant, and there is not such a well defined sequence of modifications on the latter; in fact it is not easy to understand how the original Merlin arrangement became established. It does seem, however, that the point has been established that complete annular grooves are necessary in order to get adequate feed into the crankshaft. We recommend that a second oil feed hole in the Merlin pin should be tried out experimentally in conjunction with By.{R.W. Bailey - Chief Engineer}'s other modifications. Rm.{William Robotham - Chief Engineer} | ||