Здесь же просто хорошая схема автомобильного парового мотора. Механизм Джоя, самый компактный по всем измерениям. Примечателен сбалансированный коробчатый золотник. Он подвешен к поршеньку, на тот изнутри давит пар, а снаружи давление атмосферное.
"The petrol engines fitted to motor-cars," says Engineering, "are rated by some makers at powers which could only be obtained if the mean pressure during the working stroke was 120 lbs. to 150 lbs. per square inch. We have always had great hesitation in accepting these figures, although assured by the makers that the actual powers stated have been recorded on the brake. Even in the Korting gas-engine, where the compression is 125 lbs. per square inch, and the maximum pressure about 400 lbs. per square inch, the mean effective pressure on the piston is only 90 lbs. per square inch. Further, the motors supplied to the North-Eastern Railway Company for their Hartlepool service, which were rated at 100 horse-power, have, it is reported, proved quite inadequate to the requirements of the traffic. These considerations all point to the conclusion that the engines fitted by some motor-car makers yield in actual fact much below their nominal horse-power. Brake trials by independent experts would, of course, settle the matter; but until authoritative figures of this kind are published we are inclined to the opinion that the actual power of a motor-car or motor-bicycle is often not much more than one-half to two-thirds of its nominal rating."
tl;dr производители бензиновых автомобильных моторов завышают фактическую мощность в два-три раза