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 hydraulic plunger clearances and an analysis of Pierce engine efficiency compared to the Phantom engine.
| Identifier | ExFiles\Box 173\1\ img169 | |
| Date | 2nd February 1934 guessed | |
| VI except when the heavy load is on the hydraulic plunger. They are using 1/4 thou' clearances on plunger less but! They are not sure it is necessary. I think that they realise it isn't as they have much longer leakage paths than we have and are pressure fed. Pierce Engine Efficiency They are getting about 180 B.H.P. out of 450 cu. ins, not a bad power output compared with the Phantom considering that they are a side valve engine. Crankshaft only 70% balanced (no big end balanced only pin & webs only) They have a odd camshaft period which they say rattles the valve gear and which they can alter with the crankshaft damper. Seems to be due to 1. Having a rubber type crank damper which we know is not 100% efficient. 2. No spring drive to camshaft but a short chain only. | ||