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).
List of modifications to a carburetter, detailing changes to various components and their dimensions.
| Identifier | ExFiles\Box 13\3\ 03-page403 | |
| Date | 19th March 1932 | |
| -4- Hs{Lord Ernest Hives - Chair}/Sec.3/WA.{Mr Wallis}19.3.32.contd (3) Modification Lec. 2993 which increases the distance between the small venture and the throttle edge in an open position to be made as one unit with the throttle body (E.32775). (4) Incorporation of draining of surplus petrol and resucking through small venture. (5) Original suction passages from, the small venture to the original suction chamber to be deleted. (6) Provision of air restoration vent from main intake to float chamber. (7) Increased clearance between float chamber wall and the float as the latter lifts to close the needle valve. (8) Suction piston to be 16 ozs. in weight and have 45o seating. one hole in side of piston .025 dia. Four holes .062 dia drilled through into the piston at right angles to the seat. The 45o seating to be cut in carburetter casting instead of using a separate piece. Similar scheme is shown on V.1324/3. The layout of steel centre guide is to Lec. 2997. (9) Main jet orifice to be .120 diameter instead of .125 dia. (10) Diffuser. (a) Delivery holes in diffuser head to be inclined as in (E.32870)., 4 in number and .125 diameter. (b) Diffuser bore to be .200 diameter. (c) Top row bleed holes to be .100 higher than shown on (E.{Mr Elliott - Chief Engineer} 32870), 6 in number and .035 dia. (d) Bottom row of bleed holes to be in original position 6 in number and .039 diameter. (e) Air supply holes in diffuser guard tube (E.{Mr Elliott - Chief Engineer} 32636) increased to .125 diameter. (c) & (d) in this section may further have alterations. | ||