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).
Report comparing the performance of standard and larger induction systems.
| Identifier | ExFiles\Box 90a\3\ Scan052 | |
| Date | 8th March 1935 | |
| FILES. X7962 8.3.35. 2 Comparison of Induction Systems. The Induction Systems compared in this report are the standard system having a pipe 1.500 dia. with 1.375 dia. carburetters and EB.818 balance piece, and a system having a larger pipe, 1.625 dia, with 1.625 dia. carburetters. When first tried the larger system had a balance piece 1.062 dia. between the halves of the induction pipe and with these conditions the maximum power output was 132 H.P. but the M.E.P. at the middle speeds was considerably less than with the standard system, due to the balance piece being too large in diameter. The M.E.P. at the middle speeds was increased considerably by using a balance piece .500 diameter, the increase amounting to 5.0 to 6.0 M.E.P. The maximum power output was reduced to 130 BHP. This large system did not give very good distribution at the low speeds and the distributor was very critical to the throttle position but these faults may be overcome by experimenting with the amount of overhang of the pipe beyond the end of the ports and by fitting a similar type of balance piece to the one used with the standard system. The power output with the standard system was 124 HP. The induction pipe depression using the larger system was considerably lower than with the standard system at high speeds, but due to the fact that the air pistons were heavy, the depression at the low speeds was higher than with the standard carburetters. Attached are curves B.V.76 & 77. Hs{Lord Ernest Hives - Chair}/R.Matthews. | ||