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).
Improving low-speed acceleration using turbulent heads and addressing engine detonation in the Peregrine model.
| Identifier | ExFiles\Box 179b\2\ img004 | |
| Date | 3rd October 1932 | |
| R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Sn.{Mr Sanderson} C. Ag. Wor.{Arthur Wormald - General Works Manager} C. E.{Mr Elliott - Chief Engineer} Ry. C. Da.{Bernard Day - Chassis Design} Hay. Hs{Lord Ernest Hives - Chair}/Sn.{Mr Sanderson}4/KT.3.10.32. X4027 X3867 TURBULENT HEADS AND LOW SPEED ACCELERATION. We have been trying to improve the low speed performance of Peregrine by means of the camshaft. We have succeeded, but are disappointed to find that we cannot utilize the modest M.E.P. that we have attained owing to audible detonation Curve C. Pr.28. We have to retard our ignition and so lose about 6 lbs/sq.in. M.E.P. up to 35 m.p.h. Our standard test is on Shell Mex petrol with a clean head. If an engine is free from pinking in this condition we find it will run on any No.1 fuel - for 10,000 miles without detonating excessively. Referring to our other units we find that J.1 head gives us decidedly better results (Curve B.) though it is a larger size. This confirms Phantom results that the turbulent head is an asset for reducing audible detonation. We could not have run 5.25 C.R. on the original P.I. head. The history of the turbulent head is that originally it was difficult on the Phantom as it produced torque reaction. The diamond engine mounting has eliminated this difficulty, therefore we think it would be a definite advantage to introduce a little turbulence on Peregrine. The maximum improvement we might be able to attain is shown on Curve A.{Mr Adams} Hs{Lord Ernest Hives - Chair}/Sn.{Mr Sanderson} | ||