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).
Engine component testing, including bearings, supercharger pads, plugs and valves, with recommendations for improvements.
| Identifier | ExFiles\Box 179b\3\ img186 | |
| Date | 10th February 1933 | |
| -3- Ha/Bur.3/ML.10.2.33. Cont'd.{John DeLooze - Company Secretary} consumption in Pts/HP/Hr. is .018 and compares very favourably with the Special Category Type Test results on Kestrel 1025 engine which shewed 13 Pts/Hr. or .14 Pts/HP/Hr. Should the bearings shew satisfactory condition after the completion of ten hours running at 891 BHP., we consider further development of the grooved bearing scheme should be carried out to avoid the disadvantages of the oil pressure and temperature effects with the existing pump. In conjunction with bearings, tests were also carried out on the supercharger slipper pads which had been modified to Ex.10336, which consists of criss-cross grooving of the pad surfaces to break up the oil film and to increase the unit pressure. These pads are much more effective than the existing standard, the grooved pads which have run for a period of eleven and a quarter hours including eight hours in excess of 890 BHP., only showed signs of slip when running at full throttle 1000 BHP after seven and a half hours; the plain pads slipping in some instances after only 30 mins. running under high output conditions. We recommend that grooved pads should be fitted to all Goshawk type superchargers. Although the bearing tests were terminated owing to an exhaust valve burning, we should point out that we have had no trace of plug trouble on this engine over a period of 28 hours running. The plugs used are K.L.G. 744 14 mm. type and have functioned extremely well during the whole time, which includes 10 hours in excess of 890 BHP. and includes full throttle running up to 1100 BHP. This is attributed chiefly to the improved cooling. The improvement is compared with the standard Kestrel cylinder blocks, in which the Lodge K.170 plugs will commence to heat up occasionally when running at full throttle for periods up to 15 minutes, and deteriorate after 3 - 4 hours of high power running. The valve which terminated the tests is a salt cooled type in S/SLV. and has run for approximately 60 hours including 28 hours at high power. Ha/G.W.Farmer. 9.2.33. | ||