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).
Engine condition report for chassis 10 G.III after a 10,027-mile test.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan092 | |
| Date | 4th May 1926 | |
| ORIGINAL Hotel de France. Chateauroux, Indre. France. To "H.S." From G.W.Hancock. G.W.H.3/R.P. 4-5-26. Report on chassis 10 G.III. after 10.027 Miles. ENGINE. x5840a Power. We have not noticed any deterioration in power with the performance of the car on the road during the 10.000 miles. We have been continually reaching 70 M.P.H. and over. Compression taken immediately after the close of test was poor. Nº1,2,3,5 & 6 compression were passing past piston rings into the crank chamber, Nº4 was fair. The detonations have not increased since our last report. These can almost be obliviated by retarding the ignition. Lubrication of cylinders. Nºs 3 & 4cylinders are now slightly over lubricated, Nº1,2,5 & 6 have become normal. Condition of cylinder walls. The condition of the cylinder walls from examination without dismantling appear to have remained good. Slight score marks previously reported cannot now be detected. Valve & Fittings. We have had no trouble with valves throughout the test. At the finish of the test Nº3,5 & 6 exhaust valves were slightly open, the remaining valves were O.K. We have reported during the test slight variations of the valve clearances, but these have never affected the running of the car. The tappets have remained fairly quiet; there has been one or two occasions when tappet noise was heard. These were quietened by slight adjustement. Examination of push rods and rocker arms show good bedding surfaces in either case. We have had an oil leak from the valve cover throughout the test. Pistons. Pistons are fitted with "L" shape piston rings E.53625; E.53749. otherwise to L.C.P. E.51487. Examinations of pistons shows an increase in carbon which now requires decarbonising. Piston knock in Nº5 cylinder previously reported has now disappeared, this has not been noticed for the last 1500 miles. | ||