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).
Various piston designs and potential modifications, including the Zephyr split piston.
| Identifier | ExFiles\Box 41\1\ Scan073 | |
| Date | 22th December 1919 | |
| X3776 Extract from R1/C22.12.19. X.2748. RE PISTONS. X.3754. <handwritten>X3776 X3751 X3465</handwritten> X.3751. I have not seen the suggestion for Mr. Barrington's Zephyr split piston. I ought ot have done so, even if the matter could not bear the time of a post to me. The descriptive advice of what you are doing should be sent parallel with the instructions to the shops because we have been over the Zephyr type just lately with a view of splitting or retesting the combination piston with modification. So far we have found nothing quite worth sending you. I am still anxiously awaiting the result of the multiple ring plunger pistons. All our studies point to the necessity of keeping the power side of the piston rigid. X.3776. We have lately thought that if a piston could be made to collapse on emergency, <strikethrough>being sprung out by as</strikethrough> steel spring against a stop which could be adjusted, one would get a scheme which is hopeful, the idea being that one steel is not likely to lose its elasticity. X.3765. We also believe that the oil piston plunger might be profitably supplemented by a steel spring, say, of 20 to 40 lbs effort, with intermittent oil, i.e. oil which is shut off on the top of the stroke, the spring would induce the oil to get <strikethrough>in</strikethrough> when it would be trapped from setting <strikethrough>out</strikethrough>, and a fairly oil-tight plunger would prevent the piston leaving the power wall. We cannot understand how the oil from the plunger piston can do any harm with an effective <strikethrough>scraperring</strikethrough>. Contd. | ||