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 test results comparing high compression and standard cylinder heads with different induction pipes.
| Identifier | ExFiles\Box 82\3\ scan0261 | |
| Date | 11th May 1935 guessed | |
| ( 3 ) CONDITIONS. Axle ratio...10 x 43 Rear Wheels..19 inch. 6 x 19 tyres. High Compression Head.Cut-out Closed. Maximum Engine revs.....4,350 Oil Temp..............102°c Small Induction Water Temp............78°c pipe. Average Lap Speed.....88.5 MPH. High Compression Head. Cut-out Open. Maximum Engine revs.....4,450 Oil Temp..............120°c Small Induction Water Temp............78°c pipe. Average Lap Speed.....89.9 MPH. High Compression Head.Cut-out Closed. Average Lap Speed.....88.5 MPH. Standard Induction pipe. High Compression Head. Cut-out Open. Average Lap Speed.....89.9 MPH. Standard Induction pipe. Standard Head Cut-out Closed. Maximum Engine revs.....4,250 Oil Temp..............110°c Standard Induction Water Temp............82°c pipe. Air Temp..............18°c Average Lap Speed.....85.59 MPH. Standard Head Cut-out Open. Maximum Engine revs.....4,450 Oil Temp..............115°c Standard Induction Water Temp............82°c pipe. Average Lap Speed.....87.4 MPH. Standard Head Cut-out Open. Maximum Engine revs.....4,450 Oil Temp..............115°c Small Induction Water Temp............82°c pipe. Average Lap Speed.....87.4 MPH. 2) SMALL BORE INDUCTION PIPE 1.375 DIAMETER. The results on the Montlhéry Track did not show any advantage or otherwise. The distribution is not too good. The two end parts show strong, centre weak; considerable time was spent with the exhaust manifold off to obtain the best setting of Carburettors. Slow running is definately no better than present standard. There has been an Induction pipe note at high speeds which could be altered in tone by the position of the throttle. ............... | ||