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 endurance and detonation tests, with proposed modifications for future type testing.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan092 | |
| Date | 26th January 1929 guessed | |
| contd :- -2- will be adjusted for the 525 HP. We are at present running an Endurance Test on an engine fitted with the 5.5 pistons. The test is being run at full 525 HP., not at 9/10ths. With the lower compression pistons, the piston does not cover the cyl. joint; the endurance test will shew whether this is harmful. We have carried out a detonation test on the engine with the 5.5 ratio, and find with the gate set at 525 HP. we could brake down to 1500 r.p.m. before detonation occurred. This gives us a good margin because with the usual propeller characteristics, the revs. will not drop below 2000 r.p.m. with the throttle at the gate. If this preliminary test with the M.S/C. engine is successful it is intended to repeat the type test with the following modifications compared with the previous test : (1) 5.5 comp. ratio in place of 6/1. (2) Stiffer big end bearings. (3) S/C. with extra heat, and modified carb. with jet control. We expect to have this engine ready in 10 to 14 days. Another point we are not satisfied with on the moderate S/C. engine is distribution. It is possible that the extra heating on the carb. will correct this, but in case this is not sufficient, we have tried jacketing the bend on the outlet volute and find that this makes a great improvement. Hs.{Lord Ernest Hives - Chair} | ||