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 endurance test results, including performance metrics and component failures.
| Identifier | ExFiles\Box 123\5\ scan0342 | |
| Date | 25th February 1939 | |
| -2- Fuel. Shell No.1. Oil. Motorine 'C' with inlet temperature controlled to 100°C. Oil pressure 28-33 lbs/sq.in. Silencer. Test bed exhaust system which is a free system and loses only 3% to max. power open exhaust. Ignition Running. Hand controlled to give minimum advance for max. power. Power. The power at the termination of the endurance was 2 - 3 BHP higher than at the commencement and attributed to later valve timing after fitting a new camwheel, following the failure of the original wheel. During the full throttle running the power developed was approximately 116 BHP at 3000 R.P.M. and 123-125 BHP at 3500 R.P.M. and 4000 R.P.M. Consumption, Petrol and Oil. Under the weakest maintained conditions the petrol consumption came out at .59 pts/BHP/hr. at 3000 R.P.M. and .65 at 3500 and 4000 R.P.M. at full throttle. For the first 7 hrs. run the oil consumption came out at 3 pts/hr. but improved to 1.5-2.0 pts/hr. This is rather higher than the Bentley V with similar close clearance Aerolite pistons which averages 1 pt/hr. We attribute this, however, to the fact that during the development running on the B.60 prior to the endurance several sets of various types of pistons were run in these bores. Failures. Commencing with the R.R. type of harmonic damper, the camwheel (Attwater fibre) failed after 7 hrs., a dozen or so of the teeth being stripped off; this wheel, however, had previously run 140 hrs. on general development. Upon dismantling the damper was found to have a number of broken springs with others digging in so that it was thought that the crankshaft oscillation as transmitted to the camwheel would be much higher than the original setting permitted, i.e. .5°. | ||