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 Peregrine engine's fuel consumption and potential improvements through valve and cam angle adjustments.
| Identifier | ExFiles\Box 179b\1\ img211 | |
| Date | 9th December 1932 | |
| HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} ORIGINAL C to SC WHL. BY R.{Sir Henry Royce} R5/W6.12.32. Sent off 9.12.32. PEREGRINE FUEL CONSUMPTION, AND POWER. We are a little shocked at Peregrine only running 13 MPG., but presume this would be very different if the speed was reduced to ordinary every day figures. With reference to the power curves I cannot think it is right to reduce the size of the inlet valves, and on reference to the valve timing diagram I should have thought that a few more degrees in the cam angles up to about 110°- 112°, and a little later timing so as to keep the exhaust in about the same place, would have been beneficial, but we naturally must submit to the result of experiments. Our earlier experiments shewed that we had to close the inlets rather late to avoid detonations, and get power at high engine revs. Naturally none of us agree that for RR. cars we should do this, except very slightly, but it should not be overlooked, even if we get some good from the turbulent head. R.{Sir Henry Royce} | ||