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).
Scheme for extra cylinder lubrication during cold starts to reduce piston seizure.
| Identifier | ExFiles\Box 132\4\ scan0007 | |
| Date | 2nd November 1934 | |
| Hn{F. C. Honeyman - Retail orders}/rths.15/KW.2.11.34. Extra Cylinder Lubrication when starting from cold. The intention of this scheme is to provide a means whereby a supply of oil can be delivered to the cylinder wall when the engine is first started up under cold climatic conditions and at the same time for the supply to be cut off when the lubricating oil is thoroughly hot. This scheme should reduce the risk of piston seizure considerably with engines run in cold climates. The scheme consists of a small hole drilled in the side of the connecting rod and fed by the main oil pressure for a short duration of the crank angle so that a jet of oil is thrown on to the pressure side of the cylinder wall. Our first attempt consisted of drilling a small hole in the big end of the connecting rod as shown on sketch B.V.28, but this did not meet with much success for two main reasons - (1) That the duration of oil supply to the oil jet was not sufficient for reliable results. (2) That the oil jet was far too low down the connecting rod for the jet to be thrown on to the cylinder wall. The next test was to drilled the hole farther up the connecting rod (see B.V.51) towards the small end bearing, but here again we did not meet with much success for the same reason as the previous test, i.e., that the oil supply was not of sufficient duration. In order to carry out this test with the hole drilled farther up the rod we had of course to use the "drilled up" type of connecting rod instead of the standard rod which has an external oil pipe. | ||