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).
Investigation into a broken exhaust manifold and a proposal for a redesigned, telescoping version to cure the problem.
| Identifier | ExFiles\Box 179\1\ img039 | |
| Date | 24th October 1931 | |
| HS.{Lord Ernest Hives - Chair} ) FROM R.{Sir Henry Royce} & E.{Mr Elliott - Chief Engineer} R1/W21.10.31. Sent off 24.10.31. 'CHINA' BROKEN EXHAUST MANIFOLD. Y5230. We have spent considerable time on examining this problem. Personally I concluded that it had nothing whatever to do with the down pipe, but was entirely due to the expansion of the manifold compared with the cyl. head, to which it is attached. On measuring up the broken specimen we find that the end which gets the hotter (the rear) had contracted in the centres .2" and the front and unbroken end had contracted .150". This could be, seen by examination of the faces compared with the copper asbestos washer which had remained with the studs. Apparently it did not break until it got to the end of the clearance in the studs. It is a little/bit of a mystery as to why the pipe gradually gets shorter, and it must be due to the bending of the casting during heating up, when the hot pipe may have cool ends which are still tightly attached to the cylinder. We are sending you tonight the best scheme we can think of for curing the trouble. This consists of making the two ends telescope into the middle casting, and has the novel feature of a non-expanding tie-bar to insist upon the xt joints sliding, so that if they are somewhat tight, or oxidise, they will not jam or the pipe behave as if solid. We hope you will be able to get a model of this made quickly. It seems quite interchangeable without altering the surrounding parts. The rather complicated design is brought about by the existing conditions which cannot be altered. J.{Mr Johnson W.M.} 1. and 3. will be simpler and more orthodox. DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} is sending the application of the P. 2. silencer with its exhaust pipe. R.{Sir Henry Royce} | ||