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).
Engine efficiency tests comparing synchronized and single ignition systems under various loads.
| Identifier | ExFiles\Box 69\4\ scan0322 | |
| Date | 18th September 1925 | |
| contd :- -4- in the standard position and synchronised ignitions gave no different results to single - see report Hs{Lord Ernest Hives - Chair}/ACL/LG18.9.25 attached to Hs{Lord Ernest Hives - Chair}4/LG18.9.25. The form of these curves shew how synchronised ignition in effect, speeds up combustion - the 'crests' shewing the advance required to give the maximum power for each. Having found that with regard to detonation, synchron- ised ignition gave us no advantage [inked out] over one, we made some tests to see if the efficiency was influenced in any way. The specific consumption curve appended shews the variation of the MEP. with consumption taken for one and two ignitions and we note that the same results are obtained in each case. This test therefore proves that the synchronised ignition gives no higher efficiency than single at full load and does not result in the more efficient burning of either the weak or rich mixtures. EFFICIENCY UNDER REDUCED LOADS. We have always found that more ignition advance can be given on reduced throttle openings than is required for full load and results in slightly more power. As the spark timing is governed by the engine speed and is unaffected by load, a tests was made with the single and double ignitions respectively, fixed in their most efficient positions at full load and readings of the specific consumption taken while the load was varied by throttling. The results are interpreted in terms of pts/HP/Hr. against the percentage of full load. contd :- | ||