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).
Analysis of noise reduction modifications for a sunshine roof, including a diagram and conclusions from tests.
| Identifier | ExFiles\Box 160\2\ scan0176 | |
| Date | 20th February 1934 guessed | |
| - 6 - An appreciable improvement was noted. The sum total of these modifications was to produce a 85 %. improvement. A similar car was as good as this without being "doctored" and the following features of difference were noted:- (1) The wooden rail above the screen protruded more on the bad example. (2) The joint at the front of the Sunshine roof was gaping. CONCLUSIONS FROM THESE FIRST TESTS. (1) The Sunshine roof is usually responsible for 50% of the noise in a bad case. (2) The joint at the front of the roof must be fine. The T.& M.{Mr Moon / Mr Moore} scheme of a plain metal strip on the outside is to be preferred to the Park Ward scheme wherever the metal strip is trimmed over with fabric. This latter scheme causes a coarse joint. (3) The old type of Sunshine roof which does not come up flush when closed is not so good as the latest type as used on Bentley, because it leaves an open edge at the rear, causing noises and a draught on the necks of the front passengers. | ||