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).
Examination of the Goshawk cylinder head, comparing it to a Marson car and detailing observed failures.
| Identifier | ExFiles\Box 180\M2\M2.1\ img038 | |
| Date | 1st May 1922 | |
| R.R. 199 (500 H) (SD. 296. 15.8.17) M.P. 176549. ORIGINAL. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to H.{Arthur M. Hanbury - Head Complaints} c. to Ds. c. to BY.{R.W. Bailey - Chief Engineer} ------------------------------------- HsS/LG26. 5. 22. GOSHAWK CYLINDER HEAD. X4225 ------------------------------------- We have examined the Marson Car as regards water passages etc. to see if there is any outstanding difference in this car compared with the Goshawk. The cylinders on the Marson being in two lots of three, they have a water inlet into each block. The outlet from the cylinder into the cylinder head is by means of 12 7/16" holes and 4 5/16". The walls of the combustion chamber are formed in the cylinder casting. Also the sparking plugs are fixed into the cylinder casting. The detachable head forms a flat plate with the valves and ports. The diameter of the pipe in the outlet of the pump is ¾" bore. The outlet from the cylinder head which is in the same position as our own, is also aluminium casting approx. ¾" bore. The water pump on the Marson is driven direct off the crankshaft so that although the rotor is considerably larger than the Goshawk, it will run at reduced speed. The Goshawk ll. cylinder heads we have had fail at the Works, have been condemned because of cracks in the head water jacket which have caused external leaks. We have experienced no trouble with valves sticking or burning. We have examined sections of the cylinder heads which have failed and found that in several cases there are cracks in the exhaust valve seating. These cracks appear to be in approximately the same relative contd:- | ||