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 power improvements and comparing the Phantom engine with Ricardo's sleeve valve design.
| Identifier | ExFiles\Box 5a\5\ 05-page131 | |
| Date | 24th April 1931 | |
| X5771 Hs.{Lord Ernest Hives - Chair} E.{Mr Elliott - Chief Engineer} } FROM R.{Sir Henry Royce} Ry. } (At Le CanadelHenry Royce's French residence) R1/M24.4.31. X.7771 X.5771 X.4540. c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} PN.{Mr Northey} POWER FROM OUR CAR ENGINE AND RICARDO SLEEVE. Mr. Elliott shows on 8.4.31 that Derby have long ago got excellent B.M.E.P. - i.e. over 110 - from our old 20 HP. at 3300. when it was giving I believe, nearly 95 HP. Our Phantom at the same piston speed - i.e. 4.5/5.5 x 3300 revs. = say 2750. should give 4 1/2² / 3² = 18/9 = 190 HP. This should give 100 MPH. with suitable gear, say 33 MPH. at 1000. We ought to demonstrate 100 MPH. at Brooklands during this summer by still higher comp. ratio and long duration cams, and higher gear. Our single valve engine will not fill up well at very high revs. Concerning Ricardo's sleeve aero engine, if I remember rightly we are comparing Kestrel with doped fuel he could have 8 to 1 compression and again get still better results, consumption and power. It all shows the enormous economy of increased compression ratio as well as extra power obtainable. I agree with Mr. Elliott that we or Ricardo should try to find a better shape of combustion chamber. I am quite content to believe that our head is more practical and efficient and we do not want the type Bentley's are trying on their new smaller car - i.e. as far as I can see at present, but it is possible ours could be better. R.{Sir Henry Royce} | ||