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).
The use and testing of an exhaust hot-spot for induction pipes as an alternative to hot water heating.
| Identifier | ExFiles\Box 50\3\ Scan099 | |
| Date | 1st June 1921 | |
| R.R. 235A. (10M T) S.H. 798. 10-12-20. G 2947 X4305 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to "CJ. c. to BN.{W.O. Bentley / Mr Barrington} c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to EWT. for R.R.Inc. for attention CY. Hs{Lord Ernest Hives - Chair}1/LGS.6.21. X.4305 - HOT SPOT INDUCTION PIPES. With reference to your telegram, we have already wired to you stating that we used no hot water on the throttle during our tests with the exhaust hot spot. We can quite appreciate your suggestion that the heat derived from the exhaust would be unsteady. We suggest, however, that if one considers the complete scheme on the car, i.e., the exhaust hot-spot in conjunction with shutters on the radiator to keep the engine house warm, we think that the hot water may not be necessary. For instance, if the engine is stopped and the water is warm, the induction pipe will heat up to the temperature of the engine by conductivity from the cylinders. When the engine is running with a light load, we find that the exhaust hot-spot keeps quite hot. We also get heat conducted through from the cylinders. Under light load conditions we require less heat. We do not think the hot water would cause any disadvantage but we are of the opinion that if we could get rid of the four small water pipes leading to and from the carburetter, we could fit the exhaust pipes without adding further complication to the piping. We are fitting up a exhaust hot spot arrangement on to a car for tests on the road. Below is a table giving the horse power with and without heat with different fuels:- contd:- | ||