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).
Improved car engine performance by analysing and potentially adopting Bentley's twin inlet valve design.
| Identifier | ExFiles\Box 17\6\ Scan134 | |
| Date | 30th August 1933 | |
| x7080 To Wor.{Arthur Wormald - General Works Manager} from Hs.{Lord Ernest Hives - Chair} c. to C. E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} Rg.{Mr Rowledge} c. to Ds. PN.{Mr Northey} c. to Bn.{W.O. Bentley / Mr Barrington} Lr.{Mr Ellor} Hs.{Lord Ernest Hives - Chair}5/KT.30.8.33. x5660. x254. x1497 IMPROVED PERFORMANCE OF ROLLS ROYCE CAR ENGINES. Two years ago we tried an 8 litre Bentley that was more than 10 M.P.H. faster than our latest Continental Phantom, and had considerably better acceleration without any marked vices that one could attribute to the power output. Since R.R. have taken over the Bentley Co. we have had an opportunity of analysing their components. We believe that the only feature where they gain is in their design of valve port and in having two inlet valves per cylinder with un-masked entry there-to. The attached series of tests are a complete vindication of the effectiveness of this arrangement in improving volumetric efficiency which is the secret of power. We think the results justify immediate design work to see if two inlet valves can be satisfactorily incorporated on our type of push rod engine. If we can get two small inlet valves, it will at once help us with silent valve operation and the elimination of timing gear rattles apart from improving the power output. We look forward to the single cylinder unit helping us with this job, because considerable development work will undoubtedly be required to retain our present immunity from detonation with a new cyl. head design. While the 12 cyl. is being designed, the possibility of a double inlet valve might with advantage be taken into consideration; at the moment the unit that requires it most is undoubtedly the new J.III, owing to its long stroke. The silent tappet development is sufficiently promising for us to ask for to be available on any new valve gear. Hs.{Lord Ernest Hives - Chair} | ||