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).
Tests to overcome exhaust fumes entering a Bentley by extending the exhaust cut-out pipe.
| Identifier | ExFiles\Box 86\3\ scan0062 | |
| Date | 4th September 1934 | |
| Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager}13/KW.4.9.34. Bentley Exhaust Cut-Out. We have carried out a series of tests to try and overcome the complaint of exhaust fumes getting into the body of the car when running with the exhaust cut-out open. We have succeeded in making a very considerable improvement by fitting a 2.00" dia. pipe 3 ft. 3 ins. long as an extension to the existing cut-out, this pipe carrying the gases just beyond the front face of the rear expansion chamber. Tests on the test bed shew this pipe extension to lose only 1 HP. more than the present cut-out, but the weight of the exhaust system is increased by 5 lbs. 13 ozs. when using 14 S.W.G. piping and 3 lbs. 1 oz. when using 20 S.W.G. piping. We consider the 20 S.W.G. piping would be quite all right for this particular job, and the additional weight of approx 3 lbs. is amply compensated for by the lack of poisonous fumes in the body. Hs{Lord Ernest Hives - Chair}/G.H. Whyman. Att: Sketch. | ||