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 crankshaft journal and big-end bearings made from zinc alloy on a 'Japan' engine.
| Identifier | WestWitteringFiles\U\January1930-April1930\ Scan126 | |
| Date | 26th March 1930 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/CHP. (Held up). c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to Rg.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} ORIGINAL Y 5770 X 5010 ZINC ALLOY BEARINGS. We have tested a set of crankshaft journal and big-end bearings of this alloy on a "Japan" engine (No.1VG-8) running on the test bed. The bearing was made entirely of this alloy, the alloy not being cast to a steel or bronze shell, as is usual with white metal. This engine was originally fitted with un-annealed bearings, and slightly varying clearances given to individual bearings. The engine was run light at speeds under 750 R.P.M. for half an hour, upon which the bearings tightened up so that the crankshaft could barely be turned by the starting handle. This tightness was permanent, and did not ease off when cold. On inspection the bearings shewed a general tightness, one having picked up slightly; the crankshaft being undamaged. The bearings were now re-machined to give a clearance of .00275 to the journals and .002 to the big-ends. The engine was run for 24 hours at light loads up to a speed of 1100 R.P.M. when a similar tightness was experienced. The bearings were removed and annealed for forty-eight hours at 100°C, then re-machined to give a clearance of .002 and .0015 to the journals and big-ends respectively. Three hours light running at 800-900 R.P.M. caused the bearings to again tighten up. The engine was kept running and the | ||