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).
Findings on pivoted brake shoes, an engine type test at Wrights, and Condor type cylinder heads.
| Identifier | ExFiles\Box 173\2\ img279 | |
| Date | 20th March 1934 | |
| 85a COPY OF REPORT RECEIVED FROM Rs.{Sir Henry Royce's Secretary} IN U.S.A. DATED 8.3.34. To Sg.{Arthur F. Sidgreaves - MD} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to HOr. c. to Rg.{Mr Rowledge} c. to E.{Mr Elliott - Chief Engineer} c. to Hy.{Tom Haldenby - Plant Engineer} c. to Lr.{Mr Ellor} c. to Lp.{Mr Lappin} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}6/HW.20.3.34. Thank you for your Hal/WJ.14.2.34. Referring to the points you raise:- (1) Chamfering the pivoted shoes certainly cured my trouble. I found, however, that these shoes had been set solid before the car left Derby, under my instructions, to see if the brakes would squeak, and that releasing these alone had a very beneficial effect on jaggers. Incidentally, I am convinced of their silencing merit because while they were solid brake squeaks were constantly occurring. (2) I have paid a second visit to Wrights to see Mr. Nutt, whom I missed on my last visit. He said they had not run a type test at 147 M.E.P., but that they had done a type test of 140 M.E.P., 2450 R.P.M. with 4 c.c. of Ethyl fluid per gallon, and he showed me the valves. The American type test, of course, includes 150 hours in all. The valves were quite good. They had salt cooled the stems only and had semi-flexible heads. The seats were narrow, being only just over 1/16" wide. (3) Cylinder heads. Nutt is keen on the Condor type cylinder head. He considers it is the best arrangement for valve size and providing room for the insert; also the best for eliminating distortion and assures a good orifice coefficient. He says he once operated a similar valve arrangement with two camshafts but acting directly on the top of the valve by providing a generous guide to take the side thrust, and that this gave him no trouble. | ||