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 strip-down, detailing component damage and proposing further comparative testing.
| Identifier | ExFiles\Box 179\2\ img099 | |
| Date | 31th December 1931 | |
| -2- cylinder block and head was blowing in the region of A.J. inlet plug. Condition of the Engine. When the engine was stripped it was found that all the head gas joint rings had burnt on a portion of their lower faces, A.J. being completely burnt through. Signs of burning were also evident on all the cylinder heads at spots which were situated on a diameter approx. normal to the diameter joining the spark plug centre lines. The burning was worst between the inlet valves and the portion of the head immediately behind the valve remote from the spark plug. Here the metal had been burnt away from the seat, which however, appeared to be in good condition. One head (B.4.) was cracked in two places between the inlet and exhaust ports. The pistons also show signs of overheating on the crown at spots corresponding to the marking on the head. The attached photographs illustrate all the above points. Summary. It is interesting to note that the condition of the cylinder heads, joint rings and pistons were almost exactly the same as those of R.11, when this engine was run under conditions of severe detonation (Report ref. Ha/ACL/D22.10.31.) We have no direct comparison on this test with a standard engine on a time basis but the fact that the condition of the engine when stripped was so similar to that of R.11, assures us that this type of head and top joint construction is a fairly sound proposition. The fact that the joint rings have burnt where they come into contact with the liners and not with the heads seems to point to the fact that the heads were keeping reasonably cool. It has now been decided to build up an engine with one standard cylinder block and one two piece cylinder block and run an endurance test detonating, in order to have a direct comparison between the two types. Ha/H.R.Young. | ||