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).
Modifications to the carburettor float design for the Vee engine.
| Identifier | ExFiles\Box 42\3\ Scan072 | |
| Date | 7th January 1927 | |
| To E.{Mr Elliott - Chief Engineer} RG.{Mr Rowledge} HS.{Lord Ernest Hives - Chair} c. to BJ. Wor.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} RR. F.10. CARBURETTERS. X3841 RL/M7.1.27. X.3933 X.3841 Confirmation and addiations to my telegram. The RR. design for the Vee probably has the defect of being too much affected by the long inclination on the plane, and possibly by the acceleration, as pointed out by Mr. Lovesey, therefore we ought at the earliest moment to have in readiness a modified design, the same as near as possible, but in effect to have the float ex central (fore and aft) with the throat. Mr. Elliott should proceed with a design, having as near as possible equal capacity each side of the double throats, and a diabolo or other suitable shaped float. This XXXXXX naturally can be in one or two pieces. It is assumed that we shall soon know the size of target that is needed for the full power - i.e. the smallest possible without losing too much power, say 2%, and with a well formed venturi it would seem that 1.75 or 1.80 would be about right. Our reason for not making a double float was simplicity and accessibility, and still holds good, and suggested to me that if we could get the float between the throats we could still obtain these advantages, and a large cheese as shewn here would be a simple modification, but I fear this may not be possible, so that two half diabolo, or large dia. cheeses may be best, but this would require considerable changes. We now have some good features for a design, and know most of the limitations, so it ought not to be a long job to change to a more perfect general arrangement. It is difficult to see how our older Claudels did not give trouble, but possibly they did, and also it may account for some of the complaints of bad distribution which were put down to air currents. However we ought to do all that we know now that it is found to be so sensitive to petrol level. At first I thought that increased height of petrol might mean more petrol in the diffuser jet, but I assume this has been tested, and that this idea is not supported by other contd :- CERTIFICATE OF INSPECTION | ||