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).
Investigations and proposals for dealing with engine overheating complaints, specifically silting up of the matrix and idling overheating.
| Identifier | ExFiles\Box 94\3\ scan0207 | |
| Date | 7th June 1937 | |
| -2- With regard to the first type of complaint, we are carrying out investigations on this at the moment and our tests to-date show that a std. Ph.III. car when idled dead slow with the car stationary will reach 100°C. in the top tank in 20 - 25 minutes on a normal warm day - 20 - 22°C. air temp. with bonnet shutters open. It will not, however, commence to lose water until 105°C. is reached (assuming steam valve is set correctly) which will necessitate idling for 30 - 35 minutes continuously with bonnet shutters open - the water loss even then is very slight. The opening of bonnet shutters or fitting of a louvred bonnet effects a definite improvement under idling conditions. These figures show that this idling overheating will necessarily be peculiar to very dense traffic such as the worst experience in London etc., and is a function of the duration and frequency of traffic blocks. Any increase in the speed of the engine or car reduces the water temperature from the figure when idling stationary. We are carrying out tests with higher speed and more effective fans and these will be complete within approximately one week. SUMMARY Our proposals for dealing with these complaints are as follows:- (1) Silting up of matrix (a) Before any matrix is changed, a road test of the car should be carried out to decide whether the overheating genuinely occurs at high speeds or whether it is an idling complaint - a flow test will not show whether the matrix is silted up. (b) If definitely a case of silting up, the matrix unit (complete with top and bottom tanks) should be replaced by one from a floating stock of Mk.V units and the defective unit returned to Works and thence to Messrs John Marston for renovation. After renovation, the matrix unit will be returned to the floating stock at the Depots. (c) We have ensured that all future matrices will have correct sized waterways and are endeavouring to find a means of stopping the aluminium corrosion - we do not know of a cure for this yet and tests will necessarily take a long time to complete. (2) Idling overheating. (a) On any complaint case, it should be checked that the steam valve is correctly set - this should be pressure tested to lift at a pressure of 2 1/2 lbs/sq.in. continued | ||