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).
Letter from Frank B. Halford discussing the design of a hydraulic rocker for a 3.5-litre Bentley engine.
| Identifier | ExFiles\Box 88\4\ scan0100 | |
| Date | 9th August 1934 | |
| FRANK B. HALFORD, F.R.Ae.S. DESIGNER OF AERO AND AUTOMOBILE ENGINES. Telephone Nos.: Gerrard 1217. Gerrard 1218. 8 & 9 GOLDEN SQUARE, LONDON, W.1. My Ref. ESM/EA Your Ref. HS{Lord Ernest Hives - Chair}/Smth/KW 9th. August 1934. Messrs. Rolls Royce, Ltd., Derby. SMITH Dear Sirs, Hydraulic Rocker. With reference to my letter of the 1st. instant when I sent you prints off a tracing Sk. 4394 showing proposed modifications to the valve gear for the 3½-litre Bentley, I have since had an opportunity of considering further the detail design of the hydraulic unit. For your information, I include herewith two prints off Sk. 4437 which is an enlarged view of the unit and shows in more detail the proposed differences from your experimental arrangement. In particular, the drawing indicates my suggestions for a ball-seat and ball-stop to limit the vertical lift and lateral float of the ball to reasonably small dimensions. Where angular motion exists - as in the case of a rocker - it is particularly desirable to maintain the ball well-centred over its seating if lag is to be avoided. I am now working on an alternative form of rocker which I think should be lighter than the experimental type which you have been trying. In this connection will you please let me have some information as to the maximum positive acceleration of the valve at 5,000 r.p.m. - or, alternatively, the greatest push-rod load when opening the exhaust valve - so that I can complete my figures of loading and stress. Yours faithfully, p.p. FRANK B. HALFORD. [Signature] TECHNICAL ASSISTANT. (E.{Mr Elliott - Chief Engineer} S. Moult) Encls | ||