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).
The preliminary general arrangement for a 28HP engine, detailing modifications and design particulars.
| Identifier | WestWitteringFiles\V\October1930-February1931\ Scan204 | |
| Date | 13th January 1931 | |
| DY.{F R Danby} FROM E.{Mr Elliott - Chief Engineer} C. to HS.{Lord Ernest Hives - Chair} Mr. ENG. SECRET 28HP. ENGINE. PRELIMINARY GENERAL ARRANGEMENT. We send you herewith a print of LeC. 2853. showing the above. This drawing gives particulars of the pistons, con. rods, valves, and valve gear, and cross sections through crankcase, cyl. block, and head, also general information respecting crankshaft and main bearings. The following remarks should be noted:- The extra sparking plug shewn is only required for special heads. The valve lifts shewn are as present standard, and therefore on the small side for the larger valves. This was satisfactory for the 3.25 bore but we should like to be able to use higher lifts if necessary now that the bore is increased to 3.4". We shall therefore modify the rocker ratio for this purpose and provide two cam lifts. The valve springs shewn are as present standard. These will be lengthened for more lift. We shall send you a scheme replacing LeC. 2833. Cylinder Head and Rocker Gear modified for the 3.4 bore. A design will also be made shewing the crankshaft in detail complete with balance weights. We have only been able to obtain one blueprint today, but will send another along tomorrow for HY.{Tom Haldenby - Plant Engineer} and RHC.{R. H. Coverley - Production Engineer} to enable them to go over the design from the economy point of view. E.{Mr Elliott - Chief Engineer} | ||