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).
Proposed modifications to a cylinder head, including hole sizes and dowel positions.
| Identifier | ExFiles\Box 123\5\ scan0038 | |
| Date | 5th August 1938 | |
| RHC{R. H. Coverley - Production Engineer}/G.Mc. BY.19/G.5.8.38. B.60. CYLINDER HEAD. Referring to G.Mc.1/MJ.22.7.38. the position in regard to the various points raised is as follows :- (1) The forward dowel and oil feed holes can be increased to .3125 reaming allowance i.e. .307 drill. (2) To reduce the holes from .375 to .3437 would mean a loss of area on these holes of 20% but there is a fairly wide margin between the area of these holes and the water inlet, and I would suggest that we try the engine in the first place with holes .3437. (3) We can arrange to modify the drilled .250 hole to .265, the centres can be widened 1/8", but we will have to modify the jointing surface to keep the jointing area right. (4) The core plug hole .7031 is demanded by the screw thread for the thermometer fitting, which is inserted into the cylinder block at this point. If the Foundry can work to the .703 core hole then we could alter the size to suit, but I think they should try it in the first place. (5) Water outlet - there is 1" space in which steam can collect, but it would not interfere with circulation, and therefore is of no moment, but you have evidently read the drawing correctly. BY.{R.W. Bailey - Chief Engineer} | ||