Fig. 114.—Sectional Views of Sixteen-Valve Four-Cylinder Automobile Racing Engine That May Have Possibilities for Aviation Service.
Fig. 115.—Front View of Curtiss OX-3 Aviation Motor, Showing Unconventional Valve Action by Concentric Push Rod and Pull Tube.
CHAPTER IX
[Constructional Details of Pistons]—[Aluminum Cylinders and Pistons]—[Piston Ring Construction]—[Leak Proof Piston Rings]—[Keeping Oil Out of Combustion Chamber]—[Connecting Rod Forms]—[Connecting Rods for Vee Engines]—[Cam-Shaft and Crank-Shaft Designs]—[Ball Bearing Crank-Shafts]—[Engine Base Construction].
CONSTRUCTIONAL DETAILS OF PISTONS
The piston is one of the most important parts of the gasoline motor inasmuch as it is the reciprocating member that receives the impact of the explosion and which transforms the power obtained by the combustion of gas to mechanical motion by means of the connecting rod to which it is attached. The piston is one of the simplest elements of the motor, and it is one component which does not vary much in form in different types of motors. The piston is a cylindrical member provided with a series of grooves in which packing rings are placed on the outside and two bosses which serve to hold the wrist pin in its interior. It is usually made of cast iron or aluminum, though in some motors where extreme lightness is desired, such as those used for aëronautic work, it may be made of steel. The use of the more resisting material enables the engineer to use lighter sections where it is important that the weight of this member be kept as low as possible consistent with strength.