Continental Motors O-200-D, Инструкция по установке и эксплуатации, Страница: 38 / 112

2-16 O-200-D & X Series Engine Installation and Operation Manual
3 January 2017
Engine Description
2-3.4.1. Pistons
Pistons are aluminum alloy castings. The skirts are solid with cylindrical relief cuts at the
bottom. Weight differences are limited to ten grams between opposing cylinders bays.
Piston pins are full floating with permanently pressed-in aluminum end plugs.
The lightweight piston has two ring grooves above the piston pin and one oil control ring
below the piston pin. The upper ring is a semi-keystone design, the second compression
ring is rectangular shaped.
Figure 2-11. Piston Features
2-3.4.2. Hydraulic Valve Tappets
The hydraulic valve tappet (lifter) provides an interface between the camshaft lobe and the
remaining valve train. Hydraulic valve tappets ride on the eccentric cam lobes, opening
and closing the intake and exhaust valves mechanically via push rods and rocker arms,
allowing conversion of the cam lobe profile into a linear movement for intake and exhaust
valves actuation. The hydraulic mechanism inside the tappet maintains zero clearance
between the valve and actuating components.
The interface between a cam lobe and tappet is intended to wear to some degree as the
engine operates. This is similar to the piston ring / cylinder wall interface that must seat
together for proper operation and wear over time.
Oil Control Ring
Rectangular
Second Ring
Semi-Keystone
Top Ring
Oil Control Ring
Rectangular
Second Ring
Semi-Keystone
Top Ring