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).
Power loss tests conducted on the Phantom single downpipe exhaust system.
| Identifier | WestWitteringFiles\R\2December1927-February1928\ Scan009 | |
| Date | 6th December 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL1 c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} OY. ORIGINAL Hs{Lord Ernest Hives - Chair}/ACL1/LG6.12.27. PHANTOM SINGLE DOWNPIPE EXHAUST SYSTEM. X8230 Further tests have been carried out with the single downpipe exhaust system in order to find the reason for the rather large power loss compared with the std. double manifold system. For these tests the complete exhaust system was used - ie. front silencer, rear silencer and fishtail. The method of the test was to obtain power curves with various parts of the system removed until finally we were left with the open exhaust. In this way we were able to find the power absorbed by each part of the system. The same test was also repeated for the standard system in order to afford a comparison. Referring to curves shewn on print V.176 the difference between (1) and (2) shew the power loss due to the manifold and front silencer. This amounts to 11 HP. at 2500 r.p.m. The remainder of the system only accounts for 2 HP. with the cutout open. The 11 HP. loss may be taken as nearly all due to the manifold itself, no appreciable loss being found to occur at the front manifold. Comparing these losses with those occurring with the standard system, which are shewn on print V.177, we find the standard manifold absorbs only 1.75 HP. at 2500 r.p.m. In this xx case the difference between cutout open and open exhaust is only 2.75 HP. contd :- | ||