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).
Summary of a strip examination on a Bentley 60 No. 1 unit after a 50-hour endurance test.
| Identifier | ExFiles\Box 123\5\ scan0326 | |
| Date | 24th February 1939 | |
| 1044. To Rm.{William Robotham - Chief Engineer} from HPS{Horace Percy Smith - Experimental Factory Mgr}/EW. c. to By.{R.W. Bailey - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} HPS{Horace Percy Smith - Experimental Factory Mgr}/EW.1/CB.24.2.39. BENTLEY 60 No. 1 UNIT. Herewith a summary of the strip examination on the above unit in accordance with HPS{Horace Percy Smith - Experimental Factory Mgr}/WSC.{W. S. Cassel}3/BA.18.2.39, after 50 hours endurance test :- Crankcase & Bearings. LOP.EB.4068. The cylinder bores are worn .0008" to .0058" near the top and a ridge .0005" to .0035" in depth has developed at the first piston ring position at T.D.C. This ridge is not limited to the thrust face but is evident on all sides of the bore. All the bores are slightly scored, and there are several minor damage marks in No.1, apparently caused by the previous valve failure. The distributor drive housing bore is deeply scored by the lower boss of the drive shaft; this is directly due to the taper pin failure in the oil pump driving gear. The general condition of the main bearings is poor; all are extensively cracked on the whitemetal surfaces and several are broken away locally: Nos. 1, & 4 cap-halves and No.4 case-half near the section faces, and No.6 cap half in the vicinity of the dowel hole. The petrol pump operating push rod (EB.4046 in S/ZN) is worn .080" on the end face at the camshaft end. Crankshaft. LOP.EB.3695. The crankshaft has been magnetically tested and is free from cracks. The maximum wear on the journals is .0018" and on the crankpins .001". Connecting Rod. LOP.2704. The connecting rods and caps have been magnetically tested for cracks, and are in good condition generally. Apart from rather deep scores in the centre of the bores of Nos. 4 & 6 big-end bearings, the condition of both big and little-end bearing bushes is good. continued. | ||