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).
Performance and issues of various engine components after mileage testing.
| Identifier | ExFiles\Box 5a\2\ 02-page131 | |
| Date | 29th June 1929 guessed | |
| -2- CARBURETTOR LOP. E.54492.- There has been no trouble with the carburettor. EXHAUST MANIFOLD LOP. E.53421.- The exhaust manifold at a mileage of 7.500 cracked and broke during a day's run close to the port of No. 1 & 2 cylinders. The fracture showed that the casting was weak, the section being only .125" in thickness. We should recommend that the thickness of the manifold should be increased, as this failure has occurred during all our 10.000 miles tests. A new exhaust manifold obtained and fitted developed a slight crack in the centre of the centre port during the 200 miles of the test. EXHAUST FITTINGS LOP. E.55357.- The exhaust pipe flange which makes the joint to the manifold was found cracked half way round when dismantled to fit the new exhaust manifold. A new flange was formed and again in this broke right off at a mileage of 7.200. This flange is a definite weakness and has broken off each time during the 10.000 miles tests. On each occasion we have had a flange with a short neck turned out of mild steel and welded on to the pipe which has given satisfactory results, the flange being made .787" in thickness. The silencer, cut-out and brackets have remained in good condition. With the cut-out open an increase of approx. 5 M.P.H. full throttle, has been obtained. No trouble has been experienced with the cut-out controls. WATER PUMP LOP. E.54728.- No attention to the water pump has been needed throughout the mileage. No deterioration can be observed. Cooling during the tests has been efficient, no boiling during the hot weather having taken place. Max. temperature reached 90°C. OIL PUMP LOP. E.53658.- The oil pressure dropped two or three times during tests, due to the release valve in the oil pump sticking in the guide, the cause being slight foreign matter scoring the valve stem. Otherwise oil pressure has been O.K. and pump satisfactory. OIL FILTERS LOP. E.51448 & E.53924.- The oil filters have been examined twice during the mileage. On the last occasion, a small amount of swarf and fluff was found on the sump filter. CRANKCASE & BEARINGS LOP. E.55342.- A slight oil leak developed from the front end through the timing gear case cover where fan pulley revolves, which indicates an increased crankcase pressure. We are of the opinion that an increased diameter breather pipe would be beneficial, as when the filler cap is released, the oil leak immediately ceases. We experienced this trouble on two or three other cars that have done 10.000 miles tests. A slight oil leak also developed from the rear end of the crankcase and drained out of the clutch case, towards the finish of the mileage. | ||