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).
Comparison of engine design principles, focusing on cooling, cylinder construction, and materials like aluminium.
| Identifier | ExFiles\Box 27\2\ Scan245 | |
| Date | 2nd July 1934 | |
| - 3 - fact the area of metal not directly cooled was surprising but Pomeroy says it has not given any trouble, but on the contrary they had suffered from wear on the cool part of the bore, and in consequence he was going all out for bypass thermo control to get a quick warm up. Pomeroy claims that this new engine is 150 lbs lighter than one it will eventually replace on production and that he has lost nothing in smoothness in using an aluminium crankcase in place of cast iron. Also that the elimination of the detachable head besides saving considerable weight has enabled him to put up his compression ratio to 6/1 on account of the improved cooling of the head. For our part we agree this may be so but then the design may have been very bad before in respect to this point. In the case of our own engines we believe the arrangement of the bolting and the cooling is technically very good, and the results have been very good, and it must be remembered also that the detachable head confers a freedom as regards combustion chamber shape not otherwise attainable. Nevertheless it must be admitted that the one piece cylinder has its points and it remains to be seen how this scheme with such improvements as are possible to combustion chamber shape compares with the aluminium integral cylinder and crankcase construction, with the same developments in cylinder bore and piston technique available though not necessarily applicable to both. E.{Mr Elliott - Chief Engineer} N.B. This report will be continued after the S.B.A.C.Pageant. There are further design notes as well as a trial of the Hayes' gearbox to be dealt with. | ||