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).
Engine modifications testing different carburettor setups and a T.T. cylinder head, noting effects on airflow and power.
| Identifier | ExFiles\Box 85\4\ scan0178 | |
| Date | 6th August 1937 guessed | |
| 2 remembered that on the standard engine the valves, ports, & induction system are all scaled up, whereas when six carburettors were used the same instruments (1 3/16" choke dia) were employed on both engines, thus introducing a relative air flow restriction in the induction system causing a proportionate drop in volumetric efficiency. Halls T.T. cylinder head Ex. 20943 was now fitted. & results are shown in Fig. 5. In a further test this time, six, S.U. carburettors were fitted, the throttles being removed. & the speed controlled by the moving the pistons up & down by Bowden cables. A slight gain in power was experienced at all speeds, but it is not thought that any further | ||