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 investigation of engine inserts, chrome plating, and a test rig for cylinder lubrication.
| Identifier | ExFiles\Box 124\2\ scan0204 | |
| Date | 5th July 1940 | |
| -6- Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}4/JMS.5.7.40. Most of these are in the various cars and test engines, all of which have been charted with corresponding mileages up to the second month of this year. Results so far obtained lead one to the belief that there is nothing to choose between the "slight additions". As for short inserts, our suspicion is that the only one worth considering is "Bricrome". This recorded as "Hicrome" on our charts the name having been recently changed. It is claimed by the makers (British Piston Ring Co., Coventry) to contain 30% Chrome, and certainly contains over 20% (by analysis). If we ever have to consider this insert seriously, the royalties make the production cost high. The patent is suspected, however, by almost everyone in the trade. Our Mr. Walker has considerable dope which we have passed on to him from time to time, the idea being that we might, if necessary, challenge the claim. We have one car running about with flash chromed bores (25.G.VI) to the extent of 2½" x .0025 thick. To date this car has done about 10,000 miles. From other sources, information would lend one to believe that the rate of wear even on Chrome, might mean at least .010 of Chrome would be required. It is doubtful, however, whether such a thick layer could be economically applied, because: a) If it were applied to an insert, then pressed into the bore, it might require grinding as a final operation, even if funny things didn't happen to the bond between Chrome and steel. In any case, we would be subject to the British Piston Ring Co's royalties. b) If it were applied straight to the bore, it would have to be ground to conformity with the bore. These suggested obstacles would have to be proved, however, because the grinding necessity quoted above is based simply on the experience gained in the immediate past with existing hones. A Rig has been completed for carrying out detail observations of the lubrication of the cylinder walls. This consists of our usual mobile rig with complete six cylinder unit mounted. The cylinder head is cut in half and suitably blanked Continued. | ||