Transactions (Volume 29 (1893)) (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1913 edition. Excerpt: ...develop. It was two or three years before I could understand what they meant. Mr. Hopkins tried very nice experiments on a little De Dion motor and developed curves of maximum power efficiency. The facts he got were all right. If you had a motor set under load in the shop to produce 13% per cent. CO2 and I to 2 CO and a trifle of free oxygen, that would be an excellent mixture. On the road you would not get those same conditions at all. I blocked a car up at the back axle and put the brake against the rear brake drums, to get road conditions, made a note of the whole range and then took the car out on the road without altering the carbureter and tested thoroughly. The road conditions were not the same as the practical conditions in the shop. The reason seems to be that the jar on the motor affects the level in the carbureter considerably, which affects the mixture somewhat. The difference in temperature inside the bonnet under different conditions affects the carburetion very much more than is generally understood. Carburetion is affected to the extent of about 15 per cent., as near as I can make out, by 100 Fahrenheit variation. Those variations of 100 occur quite often. I ran with a thermometer in the radiator cap and got the temperature of the circulating water. If the circulating water is say 120 to 130 running on a level and you start to climb a steep hill, the circulating water will climb up to 160, 180 or even 200, and the exhaust gas analysis will change very materially without any adjustment of the carbureter at all. It will immediately become very much richer. It is leaner when it is cold and richer when it is hot, and varies materially. That is, if one were to give any opinion, the motor heats up when it climbs a hill, the...