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 issues, adjustments, and exhaust system trials.
| Identifier | ExFiles\Box 6\7\ 07-page164 | |
| Date | 26th October 1931 | |
| Please file under X583D. 25 H.P. exhaust systems 18.G.IV. 26/10/31. Over-run 50-40 Boom ) Diamond Forward 40-45. Boom ) Mounting. Clutch does not stop easily. Not too easy getting out of 3rd. Sideshaft and 3rd. noisy. Starter carb. too weak. Front brakes thump. Dynamo cuts in 14 m.p.h. Ignition too far advanced. Detonations. Main crank period commences at 55 m.p.h. - 3rd. Top mean speed 71 m.p.h. Slow running moderate. Knob of brake lever vibrates. Not easy to get into reverse. 28/10/31. Torque reaction dampers reset to 7 lbs. load. 30/10/31. Unit No. G.XI. Valve timing set .020" clearance. I.O. 9° A.T.D.C. E.O. 4.5° B.B.D.C. I.C. 5.1° A.B.D.C. E.C. 1.1° A.T.D.C. 31/10/31. Exhaust Systems. (1) 2" straight through. P.II. short type silencer, 1 1/2" fishtail pipe. Fishtail area = P.II. Very tinny at front end of main silencer. Audible ticking over and up to 50 m.p.h. in the back of the car. Exhaust boom on pick up and overrun 40 - 50 m.p.h. (2) As above but front expansion box with C.I. end and lead-in pipe. Little if any improvement for tinniness, booms reduced and raised in speed. Tinniness still audible in the back up to 50 m.p.h. The worst boom period is now about 60 m.p.h. (3) As (2) but fishtail changed to 1 1/2" dia. pipe. Tinniness as before. Booms improved particularly the one at 60 m.p.h. Lagging on and off inter pipe and expansion box, no difference. | ||