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).
Meeting notes discussing design improvements and modifications for engine cylinder block cores and castings, specifically for the Phantom III.
| Identifier | ExFiles\Box 142\4\ scan0045 | |
| Date | 25th November 1936 guessed | |
| (Sheet 2) It should be pointed out that since these cores were made the core boxes have been gone over again, and the sections brought up more nearly to drawing standard. (3) It was also suggested that the roof of the jacket core should be doubled in thickness where it passes over the gas passage ways. (4) Mr Raby said that he had for many years advocated starting with a single cylinder and making up cores for this before embarking on a multi-cylinder block. It is impossible to judge of the passage ways entirely from drawing sections, but the production of a set of jacket cores etc. for one cylinder only enabled the foundry to form fairly conclusive views, and these cores formed the basis of any proposed modifications. We are arranging to carry this out in connection with revising the coring of the four port Phantom III cylinder head. It will be realised that one of the major difficulties is that the spacing of the six stud bolts, the two sparking plug bosses, the exhaust and inlet gas passages, and the passages for tappet rods, which are all grouped round a single combustion chamber, and which do not leave very much room for jacket core thicknesses between. We are hoping to improve matters by increasing the centre distance of the studs from the cylinder bore. (5) One of the points raised was the question of making the stud bosses oversize, which is considered necessary on a long casting where contraction troubles are likely to occur. Although allowance is made for contraction this feature is a variable quantity in practice, and it is necessary to elongate stud bosses in many instances where this occurs. (6) It was agreed that internal gas passage ways could be dimensioned at .175 thick, as now, with the expectation that these would turn out in practice to be .187. (7) In the case where minimum thickness of jacket space requires to be settled as a fundamental to the design which occurs where twin gas ports are used with a | ||