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 development issues concerning gaskets, inlet valve height, induction passages, and tests on an 8:1 compression ratio engine.
| Identifier | ExFiles\Box 134\2\ scan0092 | |
| Date | 9th November 1936 guessed | |
| -3- Gaskets. In the early stages of the development of this engine trouble, due to detonation and plug overheating, was experienced. This was ultimately traced to the use of a C and A gasket which is appeared would get a little frayed at one point, the sharp points of copper would become incandescent, set up detonation, plug overheating and pre-ignition. The trouble was cured by using a solid gasket. As, so far, we have almost always used an alum gasket this trouble has not arisen. Height of Inlet Valve above Piston. This distance appears to have a very considerable affect on the characteristics of the engine. The closer the valve is to the piston then the better is combustion, the higher the power, and the smoother the engine. At present we are running with the valve head flush with the cylinder face as standard. A series of tests were, however, carried out reducing this gas thickness between pistons and head, but unfortunately it also raised the C.R. and reduced the throat area, both of which items may have had a very considerable effect and are not therefore considered of much value. Induction Passages. In the original head, as suggested by Whatmough, the induction passages were cast in the block. With carburetters at both ends this is fairly satisfactory, but is apparently not to be compared with the normal induction pipe with two or three carburetters. 8:1 C.R. Engine. A 2-litre engine was fitted in a Triumph chassis and had a cast iron cylinder head giving an 8:1 C.R. This car was started up from cold and almost immediately pulled away on top gear, using Redline No.3 fuel (67 oct.) without detonation. The car was taken for a run and on one occasion detonation at about 40 - 45 m.p.h. could be heard. Also, after a fact stretch, when approximately 70 m.p.h. was reached, severe detonation was heard at about 5 m.p.h. on top pulling hard. It must be borne in mind however, with these facts, that Mr.Lee the chief engineer and owner of the car stated that the engine was in very poor condition and promised, on its being put right, to send it up to Derby to let us try it for ourselves. continued. | ||