Fig. 29. Carburetor
In "shop talk," the engine may be described as follows—Bore of cylinder 41⁄2 in. Stroke 41⁄2 in. Crank shaft 13⁄8 in. Revolutions per minute from 60 to 750. Propeller shaft one inch. About 15 or 16 horse-power. A float-feed carburetor, [Fig. 29], was installed at the same time. This carburetor is an excellent one. It insures a regular supply of gasolene and air, in proper proportion, and prevents trouble when the motor is in use. The float guarantees an even level of gasolene in the float chamber at all times. The proper balance of the cork float closes the supply of gasolene automatically when it reaches the proper level. This prevents waste of fuel, every drop being thoroughly vaporized and mixed with the proper amount of air. The spraying nozzle is higher than the gasolene in the float chamber, and prevents the gasolene from getting into the engine, unless it is running. The throttle valve on the carburetor gives the operator the power to change instantly the speed, without changing the timer, and affords him absolute control of the engine.
When all the machinery was in place, and the propeller attached, Mr. Watts told the boys that he would finish up the work of installing the next day, and would then run the engine "dry" for an hour or two, to get everything working nicely before declaring the Caroline ready for sea.
It was just two weeks from the day the stuff arrived when the engine was finally installed.
"That's pretty quick work," declared Walter, "and if the boat were varnished, we could have her in the water in a couple of days."
In the evening, as all the Greggs were seated on the veranda, Fred tried to explain to his father the installation of the engine, but he failed to make himself quite clear.
Mr. Gregg said to him: "You seem to have grasped the theory of the matter, but I see you don't understand some important points, so I think a few suggestions may be of use to you. I will not confine myself to marine motors altogether, as gasolene engines are used for many purposes, more and more every day. With regard to installing an engine in a boat, the first question is the bed, as you have seen in your own case, where your foundation is made good and solid.
"Small engines may be supported upon a single cross piece at each end of the bed, but this method should be employed only for the smallest sizes.
"The heaviest, and in most cases the hardest, pipe to fit up is the exhaust. It runs from the exhaust nozzle on the engine to the muffler and thence outboard.