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).
Test report on B.10 unit with a special crankshaft, focusing on noisy Textolite gears and an endurance test failure.
| Identifier | ExFiles\Box 85\5\ scan0071 | |
| Date | 8th August 1934 | |
| X217 8.8.34. B.10 UNIT (1.000" CRANKPINS). This unit had a special crankshaft (EX.14081) having 1.000" wide crankpins, but with standard journals. The Connecting Rods (EX.14210) had 1.000" wide Big Ends to suit the Crankpins and .050 thick R.R. Lead Bronze Strip Bearings. The Crankshaft main bearings were standard white metal. Textolite Cam Wheel and Water Pump Pinion were fitted and when unit was first run the engine gears were very noisy, the two Textolite gears were oversize and very hard in mesh. After the running in period the gears had improved somewhat, but even then they were extremely noisy. A new cam wheel having .004" backlash was then fitted and at the same time the Idler Wheel was moved out of mesh from the Water Pump Pinion. This alteration improved the gears a little but there was still far too much "whine" for the gears to be passed. From the experience gained on B.7 unit when this unit had Textolite gears it was decided to run the Endurance Test on B.10 which was necessary to prove that the new Connecting Rods and Big End Bearings were satisfactory and then to see if high speed running would improve the gears. The gears on B.7 unit improved considerably after running at high speed for some time. The Endurance test consisted of 10 hours at full throttle each hour being run as follows - 45 minutes at 4000 r.p.m. 10 " " 4250 " 5 " " 4500 " After 1 hour the oil pressure failed and the unit was returned to the shop. The reason for the loss of oil pressure was the fact that the main Gallery Oil Pipe had failed at one of the soldered joints. The failure of the Gallery Pipe joint was put down to the poor tensile strength of the Soft Solder at temperatures above 100°C. | ||