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).
Properties of airship diesel oils and subsequent tests on nozzle and piston development.
| Identifier | ExFiles\Box 133\3\ scan0063 | |
| Date | 6th March 1939 | |
| -3- Fuels. Anglo-American Airship Diesel Oil. Spec. Gravity............... 0.850 Flash point.................. 210°F Initial boiling point...... 200°C Viscosity (Redwood No.1).. 35-40 secs. at 100°F.{Mr Friese} Anglo-Persian Airship Oil. Specific Gravity........... .832 Flash point.................. 210°F Initial boiling point...... 235°C Viscosity (Redwood No.1).. 31.5 secs. at 100°F.{Mr Friese} (A) Tests carried out on original cylinder. Nozzle Development. The injection valve setting is the static pressure required to lift the nozzle valve, and except in the case of the inverted valve, this pressure is considerably higher than that at which the valve closes. Pump Advance refers to the crankshaft position for closing of the injection pump inlet port. The optimum performance of 101.6 lbs/sq.ins. BMEP at 2000 R.P.M. was obtained with a Bosch nozzle employing integral construction of valve guide and seating as compared with a similarly dimensioned nozzle in an RAE indicator - separate seat and valve assembly - which gave only 94.8 lbs/sq.in. BMEP. A further advantage of the Bosch assembly is the lower injection pressure of 3000 lbs/sq.in. as against the 5000 lbs/sq.in. required with the R.A.E. nozzle. The advantages of the integral valve and seat construction are very evident from these results, and are presumably due to the better alignment possible with this construction. A modified piston was made which gave a more compact combustion space requiring less fuel penetration to reach the piston crown. Results showed a power output about 1.0 BMEP less than with the other piston, and, using an RAE nozzle a reduction in injection pressure to 3000 lbs/sq.in. was possible. Nozzle | ||