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).
Results and observations from a series of oil pressure tests, concluding with findings from an engine strip-down.
| Identifier | ExFiles\Box 179b\3\ img085 | |
| Date | 31th January 1933 | |
| -3- give 2250 R.P.M. Times quoted for regaining oil pressure were taken from the time of opening up after the slow running period. Results. (o) All pressures taken at the main bearing cap oil feeds were the same and equal to the pressure measured on the normal oil pressure gauge, in addition to which when the oil pressure was regained after an imaginary roll there was no discernible lag in the system. (i) Tests were made with oil inlet temperatures varying between 70° & 80°C. At the extremes of inlet temperature the time taken to regain oil pressure only differed by 8 secs, being 40 secs. at 70°C. inlet and 32 secs. at 80°C. inlet. (ii) The length of time of slow running was increased in stages to 30 secs. without materially affecting the time taken to regain pressure. General observations during foregoing tests. As far as could be ascertained a core of air formed in the oil feed pipe when the air bleed was opened, this caused the oil pressure to fall almost to zero after about 8 secs. on opening up the pump had to prime itself and clear the air from the feed pipe before the oil pressure attained its normal figure. This took from 30 to 40 seconds according to the inlet oil temperature prior to which the pressure remained at zero. (iii) For this test the engine was shut down to slow running for 10 secs. and then opened up to normal speed which was held for 30 secs. This procedure was repeated 50 times. During the whole of the various tests carried out, the engine has run approx. 40 mins. under load without oil pressure for individual periods up to 40 secs. each. Strip. When stripped there was very little conclusive evidence of any shortage of oil anywhere. All the bearings except Nos.1 and 3 Big ends were in normal condition. The whitemetal inside the blocks of these two bearings had, however, assumed on the upper halves a highly polished appearance in one place on each. | ||