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 table of radiator and engine cooling metrics for various car models, based on litre displacement.
| Identifier | ExFiles\Box 24\4\ Scan111 | |
| Date | 5th October 1923 guessed | |
| COMPARISON ON LITRE DISPLACEMENT BASIS. First Column Group: Car. Order of merit. | Area of matrix face per litre displ: sq.in. Fiat. | 207 R-R 20 HP. | [struck]132[/struck] [written]131[/written] Panard. | 111 Bentley. | 111 Delage. | 98.7 Isotta. | 92.0 Hispano. | 88.6 Farman. | 83.6 Voisin. | 83.5 Napier. | 79.5 [written]New R.R. Rad.[/written] | 68.7 Minerva. | 67.6 [written]R-R 40/50[/written] | 67.6 Packard. | 64.6 Second Column Group: Car. Order of merit. | Water capacity per litre displ: galls. Fiat. | 1.468 Bentley. | 1.337 R-R 20 HP. | [struck]1.336[/struck] [written]1.3[/written] Minerva. | 1.237 Delage. | 1.09 [written]R-R 40/50[/written] | [written]1.05[/written] Napier. | .92 Voisin. | .9 Third Column Group: Car. Order of merit. | Surface of core per litre displ: sq.ft. Fiat. | 44.9 Panard. | 33.2 R-R 20 HP. | 33.0 Isotta. | [struck]32.0[/struck] [written]26.6[/written] Hispano. | 25.6 Farman. | 24.25 Bentley. | 24.0 Minerva. | 22.6 [written]New R-R Rad[/written] | [written]21.0[/written] Napier. | 20.5 Delage. | 20.3 Packard. | 20.15 [written]R-R 40/50[/written] | [written]19.98[/written] Voisin. | 18.1 Fourth Column Group: Car. Order of merit. | Surface of core per litre displ: per inch of depth. sq.ft. Fiat. | 14.9 R-R 20 HP. | [struck]8.5[/struck] [written]8.35[/written] Panard. | 8.3 Bentley. | 8.0 Isotta. | 6.74 Farman. | 6.6 Hispano. | 6.4 Delage. | 6.25 Voisin. | 6.03 Packard. | 5.21 Napier. | 5.1 Minerva. | 4.64 [written]New R-R Rad[/written] | [written]4.37[/written] [written]R-R 40/50[/written] | [written]4.15[/written] Total core surface per cu.ft. of vol. taken as :- AIR TUBE 110D S.Ft ZIG ZAG DIAGONAL 125D S.Ft STRIP FINS 110D S.Ft CONTINUOUS FINS AND TUBE 130D S.Ft | ||