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).
Connecting rod tests for Kestrel engines, comparing Lead Bronze and White Metal bearings.
| Identifier | ExFiles\Box 179b\3\ img189 | |
| Date | 14th February 1933 | |
| To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to Sg.{Arthur F. Sidgreaves - MD} For. c. to Rg.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to Hy.{Tom Haldenby - Plant Engineer} Hs.{Lord Ernest Hives - Chair}11/MJ.14.2.33. X3859. X2965. KESTREL ENGINES. CONNECTING RODS. A number of tests have been carried out on Kestrel connecting rods and reports are being sent out. Briefly, the position is as follows :- Test (1). We have run a test with an engine fitted with Lead Bronze bearings in which the oil pressure is cut off for 45 secs. by a means of introducing an air leak on the suction side. This test is identical to the test which was carried out on white metal bearings. There were no grooves in the main bearings. We have run for 1 hr. and the pressure is reduced to 0 for 45 secs. fifty times. The object of this test was to see that Lead Bronze would stand up with shortage of oil. The result of the test shows that the Lead Bronze bearings are in a better condition than the White Metal after a similar test and therefore there is no need for anxiety that the lead bronze will show up any worse when used under the same conditions as White Metal. Test (2). High Power Test. We have two Kestrel engines which are running at 2750 R.P.M. approx. 900 HP. One is fitted with present standard rods, crankshaft, two piece cylinders. The other engine is fitted with articulated rods, short throw crank. Both engines have Lead Bronze bearings fitted with grooves. The engine with the standard rods has completed eleven hours at 900 HP. and the big end bearings are absolutely perfect. The test was stopped down because of failure of exhaust valves. The engine with the articulated rods has completed about fourteen hours. The bearings have not been taken down after the last run. The reason the test was stopped was because of failure of exhaust valves. The exhaust valves on both these engines are our standard Silchrome material Sodium filled. On the "R" engine the exhaust valves were made in Firth's Crown Steel Sodium filled. Until we started to run these high powers we had no trouble with the Silchrome Steel. The next test we run on these engines will be with Firth's Crown Valve Steel. | ||