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).
Technical report on a visit to E.R.A. detailing their racing car and engine specifications.
| Identifier | ExFiles\Box 128\1\ scan0177 | |
| Date | 12th November 1934 | |
| To E.{Mr Elliott - Chief Engineer} H/GRY.{Shadwell Grylls} X3531 E/TSN.2/MN.12/11/34. VISIT TO E.R.A.'s. They have built three cars so far, 1100 c.c., 1500 c.c. and 2000 c.c. All weigh 13 cwt. Mays reckons the 2 litre does about 155 m.p.h. The horse-powers they get are 130, 187 and 230 respectively, at engine speeds of 8000 R.P.M. down to about 7000 R.P.M. They use 2-blader Roots blowers vertically in front of the engine, driven by bevels at 1.8 times crankshaft speed, and the boost and compression ratios are 18 lbs. and 7¼ on all the cars. The fuel they use is 40% Benzol and 60% methanol, with some acetone for easy starting. This is similar to our speed record fuel. Going up from 7 : 1 compression gave a lot more power. They find now that they get much more power without detonation with 100% ethyl alcohol. They reach their boost at about 2500 R.P.M. and it does not rise however fast they run, indicating good valving. The engine is basically the Riley 6, having a cast iron mono-bloc, with no water between the bores, and the camshafts fairly high up in the crankcase on either side. The head is aluminium, and there are short push-rods and bell-cranked rockers. The valves are at 90º in a hemi-spherical head, seating on the aluminium. The plug is towards the side of the hemisphere, nearly vertical, and is pocketted. It communicates through a 3/16" hole about ¾" long. The gasket is a thin sheet of steel. The exhaust valves have a dural rod pushed up the stem from the head end. They use about 96º overlap. The exhaust valve opens 45º early, much later than we use. Pistons are sand cast slipper type, much domed, with two small gas rings and a perfect circle scraper, all at the top. They have only had piston trouble when they used magnesium. Contd: | ||