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).
Test report detailing vehicle performance characteristics including braking, engine timing, and suspension.
| Identifier | ExFiles\Box 180\M4\M4.1\ img008 | |
| Date | 16th December 1920 guessed | |
| Contd. -2- Brakes - No jaggers. Foot brake - good but spongy. Side brake - very poor. Distance to pull up at ( clutch out - brake hard on) Foot brake Side brake 20 M.P.H. 35 ft. 83 ft. 30 M.P.H. 54 ft. 238 ft. 40 M.P.H. 112 ft. 668 ft. Engine Valve Timing. I.C. 12° B.T.D.C. ) I.O. 70° P.B.D.C. ) E.O. 20° B.B.D.C. ) .002" clearance. E.C. 27° P.T.D.C. ) Bore of cylinder. 3¼" - Stroke 5¼" Valve lift Inlet .434" Exhaust .443" dia. of port 1.843". Compression. No.5 78 lbs. No.3 77 lbs. cu. capacity 164 cu.ins. Vacuum in Induction Pipe. Springing. Rear - two elliptic springs across rear attached to brake. Front - Two elliptic springs front axle, fastened front of centre. 4 Hartford shock Absorbers fitted - 2 front and 2 rear. working crossways. Friction on rear shock absorbers - 21 lbs. - friction by steel and wood. Tests over bump on road - 20 M.P.H. Car holds road. 30 M.P.H. " " " 40 M.P.H. " " " 45 M.P.H. leaves road and throws passengers. Without shock absorbers car does not hold road so well but is more flexible over granite roads - front springing bad. Ignition. Delco coil only - Timing fully retarded 10° P.T.D.C Advanced 17° B.T.D.C. auto:Governor. Full advanced on Goven: 42° B.T.D.C. Order of firing 1, 5, 3, 6, 2, 4. Steering. Reversible - not self-centering. Road shock on steering wheel very bad - no wobbles. Friction on pivots - 8 lbs. required first initial pull from Contd. | ||