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).
Specifications and spring compression data for a Marmon Car.
| Identifier | ExFiles\Box 32\5\ Scan130 | |
| Date | 24th December 1920 guessed | |
| R.A.B. No. 15/22 Report No. N.2. Contd. -3- Marmon Car Slack in Transmission. Top gear measured on road wheel 1 3/16". Lean of pivots N.S. 9/16" O.S. ½" measurement taken at 9¾' length Particulars of Valve. Head 1.98" Stem .3735. Length overall 6.0. Thickness at head .150 (Convex head) Angle of seat 40°. Dia. of port 1.843. Two valve springs - Small Spring particulars. dia. of wire .150 Length 2.825 Outside dia. 1.250 No. of coil 8 Large spring particulars. dia of wire .175 Length 3.200" Outside dia. 1.900 No. of coil 7 Working compression 2¼". Large spring compressed. Combined spring compressed. Small springs compressed. 52 lbs. 2¼" 82 lbs. 2¼" 30 lbs. 2¼" 64 " 1¾" 113 " 1¾" 50 " 1¾" 80 " 1¼" 130 " 1¼" 70 " 1¼" 90 chock-a-block. 170 " 1" 90 " 1" 190 " chock-a-block. 106 " chock-a-block | ||