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).
Series of questions regarding the optimal design and specifications for piston rings.
| Identifier | ExFiles\Box 148\3\ scan0162 | |
| Date | 13th October 1936 | |
| -4- Hs{Lord Ernest Hives - Chair}/Mths.{Reg Matthews}16/KW.13.10.36. Side Clearance. What do you consider to be the correct side clearance of rings ? What effect has increasing or decreasing this clearance ? Our existing piston has side clearance for all rings of .002" with a plus limit taking into consideration groove and ring tolerances of .0015", do you consider this to be excessive ? Do you think scraper rings should have more clearance than the compression rings ? Clearance at back of ring. What do you consider to be the maximum and minimum clearances at the back of the ring to be ? Provided there is clearance, do you attach much importance to it ? Ring Width. What do you consider should be for this type of piston the correct ring width ? And what would you suggest for the ratio of ring to land width ? Stopped Rings. Do you consider stopped rings to be an advantage from the point of view of quick running in ? Or do you think that non-stopped rings have the advantage in every way ? Ring Joint. Is there any advantage in having a butt compared with scarf joint ? Has the scarf joint any more tendency to flutter at the tips than the butt joint ? Number of Rings. What do you consider to be the ideal number of rings ? Do you think three compression rings of lower pressure and narrower width better than two high pressure rings ? | ||