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).
Summary of tests investigating different types of power loss during engine running and their potential causes.
| Identifier | ExFiles\Box 179b\3\ img211 | |
| Date | 1st February 1933 | |
| -21- GENERAL SUMMARY OF TESTS. It will have been noted from the above description of the tests that several investigations were proceeding simultaneously and in consequence the tests relating to any one line of enquiry are somewhat scattered. For convenience it is proposed to collect the relevant data under suitable headings and briefly discuss the general results. Loss of Power during Running. From an examination of the tests this may occur in three different ways :- (1) More or less steady falling off in power as in Tests 2h, 2d. (2) A sudden drop in power without subsequent recovery as in Tests 2f, 2g, 3b and 3c. (3) A sudden drop in power with almost immediate recovery as in Tests 2k, 2l. In all the above cases, no matter what is the primary cause, the loss of power is due to some change in the jet of oil issuing from the injector. In Tests 3b and 3c this is known to be a leakage in the fuel system causing a loss of sharpness of injection and otherwise modifying the spray. The practical cure for loss of power while running is to adequately cool the injector, keep the nozzle holes clear and ensure that the injection system is free from leaks and in all other ways is functioning correctly. Two working theories were advanced to account for the loss of power. (a) Vapourisation of the lighter fractions of the fuel in the overheated nozzle. (b) Formation of a carbon deposit in or in the region of the nozzle holes. | ||