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).
Comparative table of specifications for various multi-cylinder car engines.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan137 | |
| Date | 21th April 1931 guessed | |
| MAKE. | Bore/stroke No. of cylinders. | Treasury rating HP. | Capacity. | Comp. ratio. | Engine suspension. | BHP. claimed. | Con. rod big ends. | Other particulars. BUCCIALI (French) | 2.87 x 4.72 / 16 | 52.7 HP. | 4020 c.c. | 5.1/1 | | 170 BHP. | | 22.5º Vee, separate cyls. and c'case, 9 main bearings, exhaust & induction on outside of Vee, valve gear apparently out-side Vee. CADILLAC | 3. x 4 / 16 | 57.6 HP. | 7400 c.c. | 5.1/1 | 5 point rubber. | 165 BHP at 3400 BMEP 85 | Side by side. | 45º Vee, alum. c'case C.I. cyls. 5 main bearings, exhaust and induction outside Vee. CADILLAC | 3.125 x 4 / 12 | 46.9 HP. | 6030 c.c. | 5.27/1 | 5 point rubber. | | | Said to be 45º. Other details probably as 16 cyl. DAIMLER. | 2.6 x 3.7 / 12 | 32.5 HP. | 3730 c.c. | 5.2/1 | | | Side by side | Double sleeve. DAIMLER. | 2.9 x 4.1 / 12 | 40.4 HP. | 5275 c.c. | | | | Side by side. | Double sleeve. DAIMLER | 3.2 x 4.5 / 12 | 49.2 HP. | 6500 c.c. | | | | Side by side. | Double sleeve. MARMON. | 3.125 x 4 / 16 | 62.5 HP. | 8020 c.c. | 6/1 | 4 point rubber. | 200BHP. @ 3400 BMEP 95. | Forked. | Alum: cyl. block & c'case in 1 piece. Wet cyl. liners of nitro-hardened steel, alum: heads, 5 main bearings, double down-draught carb: above Vee, exhaust outside. MAYBACH. | 3.386 x 3.93 / 12 | 55HP. | 6970 c.c. | 5.6/1. | 3 point | 150BHP @ 2800 BMEP. 99.7. | Side by side. | Alum: cyl. blocks & c'case in 1 piece. Dry C.I. liners, 8 main bearings, exh: & induc: outside Vee. Two dual Solex carburetters. MAYBACH ZEPPELIN. | 3.62 x 3.93 / 12 | 62.9 HP. | 7980 c.c. | 5.35/1 | 3 point | | Side by side. | Same as other Maybach probably but with larger bore. TATRA. (Czecho-Slovakian). | 2.95 x 4.44 / 12 | 41.8 HP. | 6000 c.c. | 5.2/1 | Rigid. | | Articulated. | Cast iron cyl. blocks @ 65º on alum: c'case. Horizontal valves. Exh: & induc: above Vee. Detachable alum: heads on curved gasket face. VOISIN. | 2.83 x 3.93 / 12 | 38.4 HP. | 4880 c.c. | 5.5/1 | | | Forked. | Double sleeve. | ||