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).
Tests to improve the slow running performance of a Bentley engine.
| Identifier | ExFiles\Box 82\4\ scan0405 | |
| Date | 23th October 1936 | |
| 200 To Rm.{William Robotham - Chief Engineer} Rm{William Robotham - Chief Engineer}/FD.{Frank Dodd - Bodies}16/JH. 23.10.36: Bentley Slow Running. The slow running of 6-B-IV after the completion of 17,000 miles was excellent, a marked improvement on the present standard car. The engine of 6-B-IV had the following non-standard parts :- (1) Deterbulated cylinder head. (2) Small induction pipe) (3) Small carburetters } 3 1/4 Litre Type. (4) Delco Remy Ignition. We have carried out a series of change-over tests between 6-B-IV and 5-B-IV, the latter car being known to be a very erratic slow runner. 1st Test. Deterbulated head and small carburetters with small dia. induction pipe fitted to 5-B-IV. Result :- Excellent slow running at 6 M.P.H. under load and with an even tick over in nutral. 2nd Test. Deterbulated head with large carburetters and large dia. induction pipe. Result :- Slow running good at 7 M.P.H. but just lacking in smoothness when running light in nutral. Remarks :- We would say that the deterbulated cylinder head is worth 80% and the small carburetters fitted to this head 20% for aiding slow running. | ||