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 design changes for various engine components, including tappets, crankshaft, and connecting rod nuts.
| Identifier | WestWitteringFiles\V\October1930-February1931\ Scan287 | |
| Date | 4th February 1931 guessed | |
| (2) (e) To avoid stopping up the waterway above the exhaust bend we have arranged a pocket for the stud hole to break into, and a groove to evacuate these pockets which should also help to feed the top lip of metal when casting. We also added .050 to dimension B. to facilitate casting. INVALID (f) On the original Japan we introduced a refinement of a rib across the rocker box floor between every push rod and the next to improve the distribution of oil to the tappets. We have washed this out as being no longer necessary as it enables us to make the cyl. studs uniform and of the minimum length within the valve gear cover. WATER JACKET COVERS ON CYL. BLOCK. Derby would like these in thin cast iron instead of aluminium and without spigots as shewn so as to disc grind both surfaces. CONNECTING ROD NUTS. Derby wish to make these from hexagon bar in nickel steel instead of milling flats and we have shewn a nut suitable for this that we used successfully on Eagle 16. TAPPETS. Derby ask for a circular recess in each side of the tappet instead of the profiled shape we had shewn. This latter was an oversight on our part but what we suggest trying is a circular hole right through as shewn removing the same weight of metal as the circular recessing. CRANKSHAFT. We propose boring out the pins and journals to the same dia. as shewn. Derby would like to use permanent expanded steel discs to cover in the journals where the dirt does not accumulate, and removable aluminium caps in the pins. | ||