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).
Comparison of engine heat rejection and efficiency between Silver Ghost, Phantom, and Hispano engines via two graphs.
| Identifier | ExFiles\Box 178\1\ img021 | |
| Date | 15th February 1926 guessed | |
| - 5 - less B.HP. than the others, gives 20% more heat to the cooling water than either of them. The Hispano gains somewhat from com-pression ratio but the graph is sufficient to shew what diverse results can be achieved in designing over-head valve engines. GRAPH I HEAT TO COOLING WATER B. TH. U/ MIN. ENGINE R.P.M. SILVER GHOST PHANTOM HISPANO It is only fair to take the road wheel H.P. developed into consideration, however, which is done in Graph II. This gives a better comparison of the results produced by the two designs. GRAPH II B. TH. U. TO WATER PER ROAD WHEEL H.P. PER MIN. ENGINE R.P.M. PHANTOM HISPANO contd. | ||