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).
Page 2 of a report on engine and carburettor investigations, including single jet carbs, manifold design, and competitor analysis.
| Identifier | WestWitteringFiles\S\September1928-October1928\ Scan161 | |
| Date | 16th October 1928 guessed | |
| contd :- -2- carrying a measured quantity of fuel. The whole system can be set in motion by a single switch and exact measurements taken over the whole speed range of the engine of : (1) the volumetric efficiency of the engine, (2) the exact air ratio supplied by the carb. i.e., the exact carb. characteristics, (3) investigation of induction pipe characteristics, valve and port shapes etc. Mr. Norton has, with this apparatus, been investigating the possibility of the single jet carb. with a view to bringing the single jet in at a lower speed than has been hitherto possible. On the Solex carb. he has reduced the engine speed at which the main jet comes in from about 400 r.p.m. to 230 r.p.m., by altering the design of the jet passages internally etc. He is working on Chrysler and Buick engines. he has many curves which shew slight torque variations due to critical gas velocities in the manifold causing fuel deposits on the sides of the manifold. These, he states, often shew up as flat spots on the road in one way or another. he has curves shewing the short comings of most of the American carburetters. He uses a special type of prony brake [redacted] to supplement the Froude water brake for large torque very slow speed work. We ourselves have found the Froude brake unsatisfactory under these conditions. INTERNAL 3RD. SPEED. This is fitted to the Paige Jewwett and the 6-cyl: Mathis. We tried the latter car fitted with a 4-seater closed fabric body carrying 4 passengers. The engine displacement is only 1991 c.c. and yet the top gear of the car was 3.9 to 1. Considering this its performance was remarkable. The car contd :- | ||