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).
The merits of pinning piston rings, comparing American and 40/50 practice.
| Identifier | Morton\M22\ img176 | |
| Date | 11th August 1920 | |
| (2) You will remember that EP.{G. Eric Platford - Chief Quality Engineer} reported that America had abandoned pinning the piston rings. I think this would reduce efficiency of gas-tightness, and occasionally become disastrous unless a more complex ring was used. Personally I am entirely in favour of a large number of narrow simple rings alternately pinned at right angles to the piston pin, the pinning being slightly staggered to break the joint. This is our 40/50 practice, but I am not sure what pistons are on the Hawk engine (Hawk North-cliffe, not Goshawk) which is here. They seem extremely good. R.{Sir Henry Royce} | ||