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).
Ongoing issues with the Goshawk II chassis regarding brakes, water loss, oil filtration, and over-oiling.
| Identifier | ExFiles\Box 5\3\ 03-page046 | |
| Date | 2nd January 1922 | |
| X4257 To E.{Mr Elliott - Chief Engineer} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to De. c. to BY.{R.W. Bailey - Chief Engineer} c. to EP.{G. Eric Platford - Chief Quality Engineer} c. to HY.{Tom Haldenby - Plant Engineer} c. to Wor.{Arthur Wormald - General Works Manager} Hal/LGi2.1.22. GOSHAWK 11. There are one or two points in connection with this chassis which we have still to get right. X4257 BRAKES. The trouble we are having with the brakes is the drums wearing badly and the brakes squeak. We have got to overcome both of these faults before they can be considered satisfactory. Customers will not endure squeaking brakes. Even on the 40/50 we have had a fair amount of complaints of this. In order to overcome these troubles the following tests are in hand. We are testing four different makes of brake fabric. We are getting some brake drums made of higher carbon steel. We are also rigging up a Goshawk brake driven by a motor so that we can rapidly test different brake materials or drums and make observations as regards the cause of squeaking. X4248 LOSS OF WATER WHEN IT BOILS. A considerable amount of water is carried away in steam when the water boils. We are trying baffles in the top tank as separators. X4232 OIL FILTER. We find that the oil filter on Goshawk cars quickly becomes silted up. As a rule, the engines we have at present, do not run very long before the engine is dismantled. So far we can only get about 400 to 500 miles running before the filter must be cleaned. We consider the reason for this is that there is no settling chamber. All the dirt and sludge in the engine drains down into the filter chamber. We consider that a settling chamber is the most effective way of filtering oil. A gauze is not very effective. If a fine gauze is used, it will never pass the oil. The most satisfactory engine we have seen as regards filtering the oil, is the Marmon, on which they have a very large settling tank. The only gauze they use is very coarse, about a mesh. The oil filter on the Goshawk cannot at present be considered satisfactory. X4128 OVER-OILING. We are finding that one reason for the excess oil is that oil is being sucked through the inlet valve guides. At present there is a great excess of oil fed to the valve rockers. We have reduced the number of oil holes by half on one engine and we still get ample. The oil which is fed along the hollow rocker enters the cup-shaped washer, runs through the slots in the wedger and is fed right on to the valve stem. We are making certain that no oil is getting through the inlet valve guides before we fit oil baffles in the crankcase. contd:- | ||