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 effects of compression ratio on heat flow and cylinder temperatures, with plans for further tests on Phantom and Falcon X engines.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan022 | |
| Date | 6th October 1926 guessed | |
| CONTD :- -3- .2" and having to pass about 9 B.T.U's per min/sq.in. we should expect the temperature of the other side of the walls to only be about 3°C higher. With regard to compression ratio it is not expected that a reasonable increase would result in much higher, if any, average temperatures, because we have found from our tests that the heat flow to the cooling water remains substantially the same. (N.B. - The heat flow per B.HP. decreases with increased compression ratio). Actual results on the Phantom shew that an increase of compression ratio from 4.12 to 1 to 5.2 to 1, results in the heat flow decreasing slightly, from 3058 B.T.U's/min. to 2960 B.T.U's/min. or 3.2% at a speed of 1250 r.p.m. From these tests we see that the temperature of the non-jacked cylinder skirt is not so very much higher than the jacketed portion and no doubt the temperature of this would be influenced by the oil temperature. As these results were only taken in connection with another experiment - where it was thought that unequal expansion of the cylinder might affect the oil consumption - they are not very complete but we are arranging to record by the same method the temperatures of the aluminium cylinder and liner at various points for the new lighter Phantom engine and the Falcon X., with a view to obtaining some information re. piston ring carbonizing on the latter. Hs{Lord Ernest Hives - Chair}/A.C.Lovesey. | ||