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 performance of Pynol fuel compared to petrol, outlining necessary engine modifications for its use.
| Identifier | ExFiles\Box 32\1\ Scan089 | |
| Date | 15th May 1929 | |
| REPORT UPON PYNOL X.1555 1 It would appear from consideration of the results given with this fuel that in order that to obtain any marked improvement in engine performance or to obtain such a good all round performance as that given by petrol, it would be necessary to considerably modify the carburetter to suit this fuel. Pynol apparently has a large distillation range which makes carburation more difficult, it also seems to require more heat to vaporize it. The high consumption & unsteady torque at low engine speeds tend to prove this. Distribution with the engine cold, or no "hot spot" on induction pipe, was not so good as with petrol. I have no figures for the explosive range of this fuel, but it appears to possess a smaller range than petrol. It has the advantage that it does not detonate so readily as petrol and an increase in power output would probably be shown by giving the engine increased ignition advance. From consideration of the H.P. curves it will be seen that the "Pynol" curve lies considerably below the Petrol curve at high engine R.P.M. A probable explanation is that with the particular setting of the carburetter for this test it would not supply a sufficiently rich mixture at this speed. From these tests it can be seen that this fuel cannot be used satisfactorily, or to its greatest advantage, without modification of carburetter, heat supply and ignition timing. AHS 15.5.29 | ||