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).
Engine failure involving bearing metal in the sump, connecting rod issues, and an investigation into valve spring breakages.
| Identifier | ExFiles\Box 5a\4\ 04-page092 | |
| Date | 20th August 1934 | |
| Hotel de France, Chateauroux. Indre. France. 20th August 1934. SO Hs.{Lord Ernest Hives - Chair} From G.W.H. c. to Hs.{Lord Ernest Hives - Chair} We have sent you the following telegram:- "TRIVES. 4B IV METAL FOUND IN ENGINE BOTTOM HALF NUMBERS ONE TWO AND FIVE CONNECTING RODS METAL BROKEN UP IN TOP HALVES. SUGGEST CAR RETURN DERBY." The car returned at noon with two broken springs, and a suspicious sound from the inside. Upon draining the sump, a quantity of bearing metal came out with the oil. We therefore dismantled the engine to ascertain the cause. We found No.5 top half of the connecting rod bearing almost all broken up, leaving very little bearing surface, left. No.1 and 2 almost in the same condition. We came to the conclusion that it would be unwise to run any further high speeds with the bearings in that condition. The timing gears also have become very bad for rattles. This will of course upset Br.{T. E. Bellringer - Repair Manager} trying the car, if it returns, but as it is, no useful comparison could be made. The valve springs broken were Nos. 2 and 11. No.2 was the single type spring we were trying. No.11 has not previously broken. The single valve spring has run 2,319 miles. The idea of Smith's that the breakages were due to the springs not seating correctly would appear to have some weight. We have found that the springs that have not broken have smaller diametre coils at the bottom than those that broke. No.1 valve which we fitted up with a single type outer spring in conjuction with the inner spring, which has a smaller diametre at the bottom, is still O.K. after 2,319 miles, whereas before, with the larger diametre coil, they were breaking every day. The standard single valve spring with the latest type inner spring, appears to be satisfactory as a double valve spring. The inner coil rubs, but has not been detrimental. 21.G.IV. This car has been held up all day endeavouring to lift the rear of the gear box to its original height. The fitting of the damper on the propeller shaft has made this job a work of art. We would like to get the designer in the pit and leave it to him. To lift the rear end up, we tried fitting a packing piece under the botton cage for the rubbers, and then found the cross member would not allow for the extra height, so we have had to dismantle it again, and place the packing under the rubber, which has taken up time. | ||