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).
Exhaust pipe clearance under the back axle for a Bentley.
| Identifier | ExFiles\Box 86\3\ scan0030 | |
| Date | 25th September 1933 | |
| X2 23 To BY.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} E.4/HP.25.9.33. c. Hs.{Lord Ernest Hives - Chair} Sft.{Mr Swift} Mx.{John H Maddocks - Chief Proving Officer} Bentley Clearance of Exhaust Pipe under Back Axle. Regarding the question of exhaust pipe clearance on the 15 Bentleys, we have had one of these over a pit loaded up with its full complement of passengers. The bump clearance from the axle to the uncompressed buffers measured 2.625", and allowing .75 for compression of rubber this gives a bump of 3.375" instead of the theoretical bump of 3". The figures for the clearance underneath the axle to the exhaust pipe representing the rebound also correspond, instead of 4¼" this dimension measures about 4". The nett result is that the car is riding a little high from .250" to .375" above the designed position. With no passengers in, the back of the car lifts .875" by measurement, but naturally this dimension will be influenced by friction in the springs and dampers. We think therefore there is very little that cannot be considered satisfactory in connection with clearances, but the initial camber of the road springs will require watching. We understand that Mx.{John H Maddocks - Chief Proving Officer} has not been able to contact theexhaust pipe with the axle under any conditions round here, or by rolling the car in the garage. GWH.{George W. Hancock - Head Chateauroux} established a maximum rebound of 3¾" by actual test in France, and taking everything into consideration we are satisfied with the cars in their present condition. E.{Mr Elliott - Chief Engineer} | ||