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).
Special tests following a failed Civil Type Test on an Exp.3 engine with two-piece detachable head cylinder blocks.
| Identifier | ExFiles\Box 179b\4\ img071 | |
| Date | 20th April 1933 | |
| ORIGINAL To From Hs{Lord Ernest Hives - Chair}/Yng. Hs{Lord Ernest Hives - Chair}/Yng.4/MJ.20.4.33. X2965. 83866. SPECIAL TESTS SUBSEQUENT TO ATTEMPTED TYPE TEST WITH TWO-PIECE DETACHABLE HEAD CYLINDER BLOCKS. Introduction. The recent failure of an attempted 50 hours Civil Type Test on Exp.3 engine fitted with two-piece detachable head cylinder blocks owing to the burning of Nos.A.3 cylinder head aluminium joint ring and compression chamber at points normal to the sparking plug axis, prompted the suggestion that Nos.3 cylinders were subjected to increased duty due to a "ramming" action of the mixture in the induction pipe. It was decided to run a series of tests to prove or disprove this theory and the Kestrel slave engine was assembled with standard cylinder blocks and run with a test fan under similar power conditions as when Exp.3 engine failed. These tests consisted of :- (1) Cylinder compression pressure tests. (2) Exhaust flame temperature tests. (3) Cylinder maximum indicated pressure tests. Details of Tests. (1) Cylinder compression pressure tests. It was thought that these tests would give an indication of any additional supercharging or "ramming" action which might be taking place in A.3 and B.3 cylinders. The engine was run at 2500 R.P.M./485 B.H.P. and compression pressures were taken in each of the cylinders of both blocks, but there was no substantial increase in pressure recorded in A.3 or B.3 cylinders, the maximum pressure being 175 lbs/sq.in. (2) Exhaust flame temperature tests. For some time we have been endeavouring to find the 'pulse' of our engine cylinder - this being taken to be a spot which showed the greatest temperature reaction to any change in working conditions. The object in so doing was to be able to establish a standard by which the safe limit of working may be judged and in addition to be able to tell when the engine was in distress from the thermal standpoint. The suggestion was put forward that the temperature of the exhaust flame would provide a suitable guide and therefore tests were carried out to find whether this reacted to a given | ||