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 component failures and inspection results, including comparisons with Bentley components.
| Identifier | ExFiles\Box 123\5\ scan0344 | |
| Date | 25th February 1939 | |
| Failures - Cont'd.{John DeLooze - Company Secretary} Regarding the rocker cover, the platform on the cylinder head to seat the joint washer is not sufficiently wide and a slight distortion of the washer allows it to squeeze in. Also as previously mentioned the rubbers under the rocker nuts are too flimsy to be durable. Inspection of Parts. A complete detailed report giving measurements etc. will be issued by HPS.{Horace Percy Smith - Experimental Factory Mgr}, but other than the parts mentioned previously in this report we give herewith a general description of the inspection. The crankshaft has negligible wear on the journals and pins and generally is in good condition, likewise the AC.7 big end bearings which are thick section, now obsolete. Regarding the main bearings which are standard R.R. whitemetal, the intermediate are badly cracked, also the upper half of the centre bearing on which several pieces of white-metal have broken away at the joint face. These compare unfavourably with Bentley V which ran 300 hrs. on the test bed, the bearings being in excellent condition. We are not unduly disturbed by the inferior condition of the B.60 bearings owing to the excessive pressure to which they must have been subjected during the development of the cylinder head which involved bad detonations, over advanced ignition and preignition. The cylinder bores, particularly No.1 show bad bore wear to the extent of .006 or .003/100 hrs. compared with .0014/100 hrs. on Bentley V.{VIENNA} Similar to the bearings, the abnormal running conditions may have been a contributory cause of this excessive bore wear, coupled with the fact that several sets of various types of pistons were run in these bores. No. 3 piston is slightly cracked in the internal web supports above the gudgeon pin boss. | ||