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 engine specifications for various American car models.
| Identifier | ExFiles\Box 91\1\ scan0506 | |
| Date | 19th May 1937 guessed | |
| CAR INLET THROAT DIA. DIST. BET. VALVE THROATS. EXHAUST THROAT DIA. MIN. DISTANCE BETWEEN BORES. VALVE CENTRES TO CYL. BORE. OVER ALL LENGTH OF CYL. BLOCK. BIG END DIA. & WIDTH. 8 BUICK SERIES 40 3 1/16" BORE 1 3/8 1 1/4 1/2" 31 1/4" OLDSMOBILE 8 CYL 3 3/8 1 3/8 1/2 1 1/4 11/16 1 3/16" 32 7/8 DODGE 3 1/4" BORE. 1 5/16 1 9/32 5/16 1 1/4 23 3/8 2.0 1.00 TERRAPLANE 3" BORE. 1 1/4 7/32 1 3/16 3/16 1 1/8 21 1/8 FORD 80 1.3 1.3 2.2 & 13/16 PLYMOUTH. 1 5/16 1.3 2.0 & 1.0 CHEVROLET. 1 5/16 1 1/8 2.25 & 1.25 CHRYSLER 6 3 3/8 BORE. 1 7/16 5/16 1 5/16 5/16 25 1/2" OLDS. 6 CYL. 3 7/16" BORE. 1 11/32 1/2" 1 7/32 23/32 1 1/8" 27" ALL EXCEPT BUICK SIDE VALVE ENGINES. | ||