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).
Tests conducted to reproduce big end split pin failures in Kestrel engines.
| Identifier | ExFiles\Box 179\2\ img203 | |
| Date | 2nd February 1932 | |
| [Handwritten] R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/LMS. R.H.P R.W.H G.P.B c.c. to Mr. Jaques. x2965 x3857 [Typed] ORIGINAL. KESTREL ENGINES REPRODUCTION OF BIG END SPLIT PIN FAILURES. Tests, using the old standard slack fitting type of split pins on the big end nuts, have been carried out on an engine running fully supercharged. The tests were carried out at high engine speeds 2400-3000 r.p.m., and were successful in reproducing split pin failures, as recently experienced in service. Poorly fitted pins, having a certain amount of initial play, were fitted to the following big end nuts :- Forked Rods. Blade Rods. No.1 Front B. No.1 B. No.2 Rear A.{Mr Adams} No.2 A.{Mr Adams} No.3 Front B. No.3 B. No.4 Rear A.{Mr Adams} No.4 A.{Mr Adams} No.5 Front B. No.5 B. No.6 Rear A.{Mr Adams} No.6 A.{Mr Adams} The engine was then run as follows :- 1 hour: 40 mins: at 2500 r.p.m. detonating. 3 hours: 20 mins: at 2500 r.p.m. rated boost. 1 hour: 40 mins: at 2700 r.p.m. Dev HP: 2 hours: 50 mins: at 2400 r.p.m. 460 HP. 50 mins: at 3000 r.p.m. 500 HP. Total Running time 10 hours. At the end of the run the condition of the pin was as follows :- All the pins correctly fitted were in good condition, tight when tried before removal, and with no signs of serious wear behind the heads. In certain cases a small patch of polished area was to be seen on the stump. The pins fitted loosely, showed varying degrees of wear, one fork rod pin from No.3 crank, and the B side blade rod pin from No.5 crank, having come out. The list shows the state of the loosely fitted pins, at the end of the run. | ||