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).
Performance of fixed throat carburetters and proposing future developments for continental models.
| Identifier | ExFiles\Box 102\1\ scan0085 | |
| Date | 30th May 1932 | |
| HS.{Lord Ernest Hives - Chair}) FROM R.{Sir Henry Royce} E.{Mr Elliott - Chief Engineer}) X5080. R3/M30.5.32. X.5080 C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} CARBURETTERS - 16-C-4. I have only driven this car a short distance, but it appears to be remarkably good as regards carburation, snap acceleration, and low speed torque. I mention this because at one time we thought this nearly impossible with fixed throat carburetters. I believe the combination that we have on this car the best that had ever been achieved with non-expanding carburetters, and one would infer that it would prove remarkably consistent. It does however strike one as being a little bit formidable for ordinary common practice. It is a really high class piece of mechanism which has been very successfully completed, and gives one a certain amount of pleasure. We believe that with a better exhaust (less HP. waste) and perhaps a rather later setting of the camshaft, as we have been favouring recently, it would give wonderful satisfaction to the owner driver. If it were urgent that we produce something with these characteristics for our continental 25HP. with this J.1. head, I should agree to its adoption as a standard for the continental model, and I am sure it would please customers as Lord Cholmondeley. If not urgent, I should push on with the semi-expanding single carburetter which would embody the few modifications suggested from the first model. This I think is an urgent piece of work for E's dept. at Derby as it will be wanted for both J.3. and Peregrine. The features that are uppermost in my mind are to increase the size of the air valve, and to arrange for the suction to operate the air valve from either the main venturi or from underneath the throttle, beyond the top of the venturi restriction. This was the wish I expressed some time ago and seems to be confirmed by HS{Lord Ernest Hives - Chair}/LOV{Mr Lovesey}'s experiments. It is intended to make it possible that when the extra air valve is wide open there is extremely little depression in the space below the end of the venturi tube. | ||