Engine component condition report for No. 21 Unit (25-EX. Chassis) after a 30,000 miles test on Shell Oil.
| Identifier | ExFiles\Box 11\3\ 03-page545 | |
| Date | 24th November 1931 | |
| X7941 No. 21 Unit (25-EX. Chassis). After 30,000 Miles Test on Shell Oil. CRANKCASE AND BEARINGS Crankcase - O.K. Main Brgs. - Whitemetal broken away on cap halves of Nos. 3 & 5 main bearings. Other bearings in fair condition. Cap of centre main bearings broken into two pieces as shown. FRACTURE ALONG HERE One centre main bearing cap retaining stud broken off on screwed portion just below the nut, broken end with nut being found in crankcase lower half CRANKSHAFT (NITRALLOY) Journals and pins in good condition. Oil deposit in crankpin bores rather more than usual for same mileage and deposit of a more solid nature, filling approximately half of each bore and encroaching upon connecting rod oil hole. CONNECTING RODS Big end bearings generally in very good condition, except for Nos. 3 & 4 Bearings on which a small area of whitemetal had broken away from steel shell. CYLINDERS Cylinder bores in good condition. (See separate chart for dimensions). Carbon deposit on cylinder head not excessive provided engine had not been decarbonised during test in France. | ||
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).