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).
Compression ignition engine design, comparing it with Beardmore's catalogue, and weighing the trade-offs between performance and economy.
| Identifier | ExFiles\Box 178\3\ img214 | |
| Date | 1st June 1932 | |
| ORIGINAL. FROM R.{Sir Henry Royce} C. to SG.{Arthur F. Sidgreaves - MD} C. to WGR. C. to RH.{R. Hollingworth} C. to HE. RECEIVED COMPRESSION IGNITION ENGINE. x4 33 Thank you for the Beardmore catalogue forwarded with your F1/LAM7632., and we return it herewith as requested. I do not think that Beardmore's show anything in their catalogue which is sufficiently attractive. I doubt if they have got quite as far as we have with our single unit 4 stroke scheme. I thank you also for the suggestion of the combustion chamber shape contained in your F1/LAM4632., but (as we have found ourselves) the valves are the bugbear of getting a combustion chamber shape which promises to be ideal. If however the single sleeve can be made to be reliable, it promises to give a port area, port openings, and a combustion chamber, which can be varied to almost any extent. In fact, it has shown in our investigations such remarkable advantages as to make it worth while to struggle hard to make the exhaust part of the sleeve action satisfactory by very complete water-cooling, lubrication, and all other advantageous features that can be thought of. You will understand that I am not expecting with the present state of knowledge to equal the petrol engine for weight per HP. output, but we have reasonable hope of getting a reliable engine of high economy at about 2.5 lbs. per MBHP. Apparently one has to choose between an engine of narrow speed flexibility and the best fuel economy, or one of great speed flexibility, with a rather lower fuel economy. These would have the open and bulb type combustion chamber respectively. For the particular work we have in mind personally I cannot see that we require very great flexibility as regards speed. As regards loads we do not think it matters about maximum economy at the maximum load, provided we get maximum economy at cruising load. (1) | ||