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).
Design evolution of the Straight 8 Engine from a two-valve ramp head to a turbulent head design.
| Identifier | ExFiles\Box 6\6\ 06-page001 | |
| Date | 7th May 1934 | |
| 605 To Mr. and WCr. From E.{Mr Elliott - Chief Engineer} E.1/HP.30.4.34.(Dictated) c.c. hs.{Lord Ernest Hives - Chair} hy.{Tom Haldenby - Plant Engineer} oft. RRC. 7.5.34. re R.R. Straight 8 Engine. ----------------------- The designs for the above were originally produced based on the two valve ramp head and much good scheming work has been done, but although there is reason for encouragement from results uptodate, the present position of the development does not justify continuing on these lines. We have therefore been changing over recently to the standard type of turbulent head as originally developed by S. and as used on the present Bentley and F.11 and at the same time we are introducing such features as thermostatically controlled exhaust heating for the induction, silent chain drive timing gears etc. based on the information obtained from America. We are attaching herewith a specification of the modified design of engine and we would point out that the best arrangement of camshaft and accessory drives that we have found also makes the engine suitable for adapting the ramp head if ever this is found to be desirable provided the cylinder head studding is suitably modified. Another point of interest is that on this engine owing to the proportionately smaller cylinder bore we are able to prevent the valves dropping on to the piston in the event of spring breakage by making the valve heads overlap the cylinder block. We should welcome any criticism of the constructive type in connection with this specification. E.{Mr Elliott - Chief Engineer} | ||