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).
Criticisms on the Goshawk 11 engine regarding the over-elasticity of its cylinder head studs.
| Identifier | ExFiles\Box 180\M1\1\ img007 | |
| Date | 8th August 1921 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to EY. ORIGINAL X4219 CRITICISMS ON GOSHAWK 11. Studs holding cylinder and cylinder head. We feel that the long studs which hold the cylinder head and cylinder on this engine are too elastic. Their torsional elasticity is very great. In screwing down the nuts on the cylinder head, one never has the feeling that they are tight. When the spanner is on the nut, the stud is twisted and when the pressure is released, the stud and the nut spring back. We feel rather concerned about this point because in our opinion the cylinder head joint must be capable of being handled by persons who are not mechanics. One would expect that any owner or driver could remove the cylinder heads and replace them. We ourselves, recently, have remade a cylinder joint on the Marmon car several times with the same gasket because we had no spare ones available. We found in order to make the joint, it was necessary to screw the nuts down holding the cylinder head, very tightly. We have pictured, that if a similar case occurred with Goshawk 11., that undoubtedly some of the long studs would be broken. We have tried screwing up the studs in a fixture and we find that we can easily break them with a 8" tommy bar. We are carrying out tests in order to prove what is the maximum length of tommy bar which can be used on these studs. After we have done all that we feel that they are likely to be a source of weakness. contd:- | ||