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 torsion test results for various engine crankshafts.
| Identifier | ExFiles\Box 63\4\ scan0076 | |
| Date | 20th June 1925 | |
| TORSION TESTS OF CRANKSHAFTS - R.R & OTHERS. | ENGINE: | STD. PHANTOM. I + AC VII | SPORTS PHANTOM. EAC XIV | 1-C-1 | STD. 20 H.P. | EXPL. STIFFENED 20 H.P. | LORRAINE DIETRICH (6 CYL.) | FIRST IN DIA III EXPL. 20H.P. L.E.C. 2480 | STUTZ 8-CYL. | F.{Mr Friese} XI. AERO | CHRYSLER "75" (6 CYL.) | EAC 10. S.S. | E.78456 WITH LARGER CRANKPINS. | |---|---|---|---|---|---|---|---|---|---|---|---|---| | PART NO.: | E.78216 | E.76836 | E.18881 | E.54064 | E.51976 | | E.82601 | | E.24667 | E78456 or E76878 | E.79351 | | 2 b. | 1.500" | 1.800 | 1.050 | 1.050 | 1.000 | CALC. BY SPECIAL FORM OF CARTER'S TORSION FORMULA. | 1.180 | 1.850 | 1.780 | 1.250 | 1.650 | 1.68 | | 8 h | .860 | .800 | .582 | .632 | .712 | | .584 | .820 | .680 | .544 | .800 | .80 | | 3/4 (d1^4-l1^4)/(d1^4+l1^4) | 3.130" | 8.295" | 3.30 | 3.21 | 3.83 | | 4.225 | 1.287 | 2.785 | 1.65 | 3.13 | 2.095" | | 3/2 r (d1^4-h^4)/l1w^5 | 6.08 | 4.794 | 5.89 | 5.441 | 5.41 | | 2.740 | 5.39 | 4.880 | 3.16 | 3.065 | 3.12 | | l. | 11.82" | 12.39 | 10.82 | 10.33" | 10.95" | 13.62" FOR "20" CRANK, 11.20" FOR PARALLEL CRANK. | 9.694 | 9.08 | 10.098" | 6.60 | 8.645 | 7.665" | | J.{Mr Johnson W.M.} INS.4 | 4.168 | 3.74 | 1.33 | 1.33 | 1.763 | 1.21 | 1.65 | 3.83 | 5.20 | 2.51 | 4.165 | 4.56 | | STIFFNESS PER CRANK - GJ/l x10^6 LBS.INS/RAD | 4.26 | 3.562 | 1.45 | 1.52 | 1.899 | TOTAL FOR 6 CRANKS: 28,600 LBS.FT. | 2.01 | 4.99 | 6.075 | 4.49 | 5.685 | 7.03 | | TEST STIFFNESS IN BEARINGS LBS.FT./RADIAN | 45,000. | 38,820 | 14,750 | 16,350 | 19,100 | 28,350 | 26,100 | 54,400 | 78,400 | 48,000 | 52,000 | 62,800 | | CORRECTIONS: | | | | | | | | | | | | | | θm radians | .168 | .1505 | .2090 | .1149 | .1342 | - | .1094 | - | - | - | .1908 | .2315 | | θc . | .0489 | .0470 | .0388 | .0341 | .0303 | - | .0438 | .0267 | - | .0743 | .0425 | .0420 | | θ . | .7861 | .8025 | .7522 | .8510 | .8355 | - | .8468 | .9733 | 1.000 | .9257 | .7667 | .7265 | | TEST STIFFNESS PER CRANK x10^6 LBS.INS./RAD | 4.12 | 3.48 | 1.406 | 1.384 | 1.646 | - | 2.22 | 5.37 | 5.64 | 3.500 | 4.88 | 6.22 | | RATIO: CALC. STIFFNESS / TEST STIFFNESS | 1.035 | 1.023 | 1.031 | 1.098 | 1.152 | 1.01 | .906 | .929 | 1.076 | 1.283 | 1.165 | 1.13 | | TEST STIFFNESS OUT OF BEARINGS. LBS.FT./RAD. | | | | | | | | | | | | | | ||