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).
The performance and wear of a rationalised 6-cylinder car, a Wraith replacement, after 50,000 miles.
| Identifier | ExFiles\Box 111\3\ scan0161 | |
| Date | 16th February 1942 | |
| Chassis To: Sg.{Arthur F. Sidgreaves - MD} from Rm.{William Robotham - Chief Engineer} 800B Rm.{William Robotham - Chief Engineer} 1/h.{Arthur M. Hanbury - Head Complaints} 16.2.42. c. to Hs.{Lord Ernest Hives - Chair} RATIONALISED 6-CYLINDER CAR - WRAITH REPLACEMENT. The 4-seater saloon with division, 3 B 50, which represents the fully rationalised 6-cylinder car with a high-powered engine, has now completed 50,000 miles. Total troubles experienced are indicated on the attached sheet. The gear-box has done better than most of the others of the new type, although it possesses all the known design defects which have been dealt with in the latest boxes now being made experimentally. This particular box has remained quiet, and the gear-change has been consistently satisfactory. The worst feature of the chassis has been the servo, which has suffered from the recent appalling weather and 'juddered' badly, due to the ingress of snow and water. The cure of this fault remains one of the post-war problems. The engine has given no trouble whatever; the petrol consumption is remarkably good for the size of the car, averaging on long runs 18 1/2 miles to the gallon. The cylinder bore wear is as follows : 3 B 50. Cylinder Bore Wear after 46,500 Miles on the road and 30 hours on the test-bed. B 60 No.4. Engine - Oil Consumption at the completion of this period - 1470. Wear measured at the Mouth of each Cylinder (worst point) Piston No: 1 .0085 ) Standard Cylinder Bores. 2 .0052 ) 3 .00015 ) Hichrome Inserts. 4 .00005 ) 5 .0027 ) Brivadium Inserts. 6 .0034 ) It will be noticed that the wear on cylinders with Hichrome inserts is negligible, whereas those without liners have reached a stage where they need re-boring. We have, of course, definitely decided to fit liners to our cars after the war, and all the figures show that we shall be able to get 100,000 miles between engine overhauls, in the hands of reasonable customers. The 8-cylinder version of the high-powered engine is still running in 30 G 7. on the bus route between Belper and Derby, and has now covered a total of 90,000 miles. | ||