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).
The condition and performance of controls, induction pipe, carburetter, and exhaust system components after testing.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan292 | |
| Date | 1st September 1970 | |
| - 3 - Controls, to L.O.P. E.72843 & L.E.C. 2118. These have operated satisfactorily & very little wear has taken place. Induction pipe & carburetter. Smaller diameter aluminium pipe & bend (water heated) to L.E.C. 2058, otherwise to L.O.P. E.72039. We have not noticed anything detrimental in the running of the engine with this pipe. It is in a good condition. The condition of the carburetter is good. There was no dirt or fluff on the filter when examined. We have had no stoppages of any kind due to carburetter failures. The carburetter, as compared with the exhaust heated carburetter, is not so good from points of getting away quickly when cold, misfires at medium speeds when running in top gear on hills, due to heavy petrol collecting in the induction pipe. This is not so noticeable if water temp. is taken care of, but would be very noticeable if a driver neglected to do so. Calorised exhaust down pipe. E.72868/9/70. During the first 2,500 miles, the distortion of the front down take pipe was such that the sliding joint at the front silencer became disjointed. This again occurred after resetting the pipe during a further 2,500 miles. We fitted a new pipe sent out from Derby. This pipe has not functioned at the sliding joint, although this was left perfectly free for it to do so. The distortion has this time caused the front exhaust box to crack half way round between the two ports. There does not appear to be any scaling of pipes, and they appear to be in good condition. Exhaust boxes. The two end lugs nearest centre of the engine broke off early in the test. During the continuation of the test, the dowel pins in the same position were broken off. The boxes remained in good condition until the last 1,000 miles, when the front exhaust box cracked half way round underneath, between the two ports. This we believe was due to the distortion of the front down take pipe, which, when the sliding joint is not functioning for some reason, reacts on the box tending to swivel the box downwards, the front dowel acting as a pivot, & the rear end being held causes a strain to take place in the centre of the box, with the result that it cracks. The sliding joint, during the latter part of the test, has not functioned. Exhaust silencers. The rear exhaust silencer is fitted with concentric tubes, & is not lagged. The rear silencer has remained in a good condition through-out the test. The front silencer is lagged & bound with sheet aluminium. The aluminium covering, early on in the test, was torn away from bands by stones, etc., & is now in a very poor condition. This, in time, would materially affect the exhaust noise. We would recommend that the material be of a tougher material. All brackets holding silencers have remained intact, & bolts in same have remained secure. With these silencers we are of the opinion that the exhaust noise is satisfactory for silence. The exhaust is free from any bad booms on retard. There has been a slight whistle at approx. 40 m.p.h. | ||