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 running and type testing experience of high-speed valve springs on Kestrel engines.
| Identifier | ExFiles\Box 179\3\ img096 | |
| Date | 22th March 1932 | |
| HIGH SPEED VALVE SPRINGS. OUTER SPRING E.31025/1. INNER SPRING E.31026/1. Test Bed Experience: Development Running. We have completed approximately 500 hrs. running on development engines fitted with the above springs, without breakage. Up to March 1930 we had completed 230 hrs. with these springs, attaining speeds of 3250 R.P.M. Since then Kestrel No.27 has run 200 hrs. with the high speed springs, the running periods being as follows:- 4 hrs. at 2700 R.P.M. 50 hrs. at 1000 - 2700 R.P.M. 69 hrs. at 2150 - 2250 R.P.M. 86 hrs. at 1500 - 2250 R.P.M. Also Kestrel No.93 has run approx. 60 hrs. so fitted at engine speeds ranging from 1000 - 2250 R.P.M. The performance of these springs on Development engines has been entirely satisfactory, and their adoption has been frequently recommended by us. Type Test Running. - Kestrel I B. No.25. This engine, which underwent a Type Test in Oct.1930, was fitted with the high speed valve springs E.31025/6. The test, which included an hours running at 2835 R.P.M. was successfully accomplished without spring breakage, and is the only type test we have run, which included an hours run at this speed, that was concluded without spring breakage. Kestrel III MS. No.13. The high speed valve springs E.31025/6 were a feature on this engine, which was Type Tested in July 1929. This test was run at a speed of 2400 R.P.M. but due to reduction gear failure, only 53 hours. running were accomplished. The springs survived the running, at this higher speed, successfully. Hw/D.B.Hall. | ||