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 unit bench tests, focusing on the unsupercharged engine's power, reliability, ignition, and servo performance.
| Identifier | ExFiles\Box 1\8\ B001_X100 Engine Chassis-page218 | |
| Date | 23th September 1932 | |
| X402 7a R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. E.{Mr Elliott - Chief Engineer} By.{R.W. Bailey - Chief Engineer} c. Ds. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}9/KT.23.9.32. PEREGRINE UNIT BENCH TESTS. We have been running this engine continuously on various tests, since our last report, 19.7.32. UNSUPERCHARGED PEREGRINE. (1) Low Speed Power. We have managed to improve the low speed power appreciably by modification to the cam forms. We cannot tell exactly how good the engine performance will be until we get the A.R. carburetter. It would appear however, with the existing gear ratio, and 6/1 compression ratio, we shall be able to get satisfactory low speed acceleration, and at the same time, a top H.P. of about 68. This power, as Brooklands tests show, will give a speed of 73 m.p.h. which may be slightly improved with the freer exhaust system. (2) Mechanical reliability. With the unsupercharged engine, we have had no mechanical failure of any sort, since the rocker pedestals were strengthened. (3) Ignition. We find with the double contact breaker distributor timing produces a difficulty in that it is impossible to set the timing on both contact breakers to occur at the same point on the flywheel. On the distributor, we are at present running, the variation is 3°. With the high compression being used, the engine is very sensitive to ignition advance, and this small variation is quite sufficient to increase the detonation on the cylinders with the earlier timing. We have had continuous trouble with ignition when picking up on full engine torque at low speeds. One fault has been shorting from the contact breaker arms to the floor of the case. This failure has occurred when the plug gaps are set at .015". Hs{Lord Ernest Hives - Chair}/Wst. is investigating modifications necessary to overcome the troubles. the various (4) Servo. We have taken some servo efficiencies. We find that the Peregrine servo multiplication is approx. 2.3 | ||