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).
Engine performance relating to turbulent cylinder heads and low-speed acceleration.
| Identifier | ExFiles\Box 1\8\ B001_X100 Engine Chassis-page221 | |
| Date | 3rd October 1932 | |
| X4027a R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} C. ES. WOT. C. E.{Mr Elliott - Chief Engineer} By.{R.W. Bailey - Chief Engineer} C. Da.{Bernard Day - Chassis Design} Hdy.{William Hardy} Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}4/KT.3.10.32. 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 utilise the modest M.E.P. that we have attained owing to audible detonation Curve C. Rs.{Sir Henry Royce's Secretary}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.I 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 or 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}/Rn.{Mr Robinson} | ||