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).
Piston and ring specifications for 20 HP engines with 3.000' and 3.250' bores.
| Identifier | ExFiles\Box 105\2\ scan0203 | |
| Date | 16th July 1928 | |
| -2- 20 H.P. 3.000" BORE. Lec.2577. Features: (1) Alteration to webs in head : one nearer split side made thick; other one thin. (2) 4 rings all stopped, instead of 5 rings 3 stopped. (3) Groove milled round below bottom scraper ring. Std. gudgeon pin fixing. This piston was to replace one that broke (in 10-G3) and was in accordance with R's telegram of 16.7.28. 5 different ring arrangements were shown, requiring 3 different designs of rings. E.55345 E.55346 E.55347 Perfect circle type. Lec.2578. Features as Lec.2577, but - (1) Single bolt pedestals. (2) Invar ring round base. (E.54929) (TRIED IN IV-G-6 UNIT AND THEN REMOVED. NO RECORD WHATSOEVER OF WHY THEY WERE REMOVED. PISTONS APPEAR TO BE IN GOOD CONDITION.) 3.250 BORE. LEC. 2698 - E.55324. Features : (1) 3.625" long. (2) New method of retaining gudgeon pin. (3) 4 rings (bottom Perfect Circle Type) (FOR USE WITH NON-TURBULENT HEAD AND STD. CONN. ROD. FITTED TO G.C.1-3 & 5 UNITS. NO REPORT TO HAND.) Hs{Lord Ernest Hives - Chair}/Tsn. | ||