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).
On fitting a radiator blind and the impact of aluminium versus cast iron pistons on engine carburation in cold weather.
| Identifier | Morton\M22\ img034 | |
| Date | 1st February 1919 | |
| Contd. -2- EH7/LG4.2.19. We think that fitting the blind to the radiator on our cars is very urgent. We suggest that the fact of fitting aluminium pistons makes the running of the engine under cold conditions more difficult. The reason for suggesting this is because the improvement one gets by keeping the water hotter is not due altogether to the fact that there is hotter water round the carburetter. One can turn all the heating off into the carburetter and still get a marked improvement. This means that the improvement is due to the cylinder itself being hotter, which is quite reasonable. When we fit aluminium pistons in place of cast iron,^the pistons will doubtless cool the cylinder tremendously. With a cooler cylinder poor petrol and a cool radiator the carburation is very bad. X.3456. Any of the old type cars which I have tried lately which have had cast iron pistons and smaller radiators have been very much better, from the carburation view, than 48-GB is, although they have been run on similar petrol. EH. | ||