In an OHV engine, the valve train process starts when the camshaft begins to rotate. At the highest point on the lobe of the camshaft, the lifter is lifted upward, which causes the pushrod to move upward as well. As the lifter raises the pushrod, the pushrod applies pressure to the underside of the rocker arm. The rocker arm is balanced between the pushrod and the valve spring. When the pushrod applies pressure to the underside of the rocker arm, the rocker arm pivots downward and compresses the valve spring. The compression of the valve spring opens up the exhaust valve and releases the exhaust. When the highest point of the camshaft lobe moves back to it’s original position, then the valve spring relaxes. This causes the valve to close and returns all the other valve train components back to their original position, too. The OHV engine, as well as the OHC engine, is synchronized with the rest of the engine cycle by the timing set.
First time Slime sealant users not only learn about the benefits that tire sealant has to offer, they also sometimes learn a bit about the make-up of their tires and valves.
On many an occasion, a new user gets to the step in our instructions that asks them to remove the valve core and there is a pause as they ponder, “What is a valve core?” If this is you, do not worry! Many, many first time Slime sealant users have asked this same question.
The valve core is a small metal piece that threads inside your tire valve stem. It consists of a seal attached to a movable, spring-loaded pin. You can see the pin sticking out of the valve stem in the picture below. This valve core is screwed inside your tire’s valve stem to prevent air loss. In fact, this valve core is literally all that is keeping your tire inflated!
When you need to remove air from your tire, you can simply depress the pin to open the valve and bleed out air. Some tire gauges have built in bleeder buttons, or you can use a pen, key or other small object to let air out of your tire. When it is time to add air to your tire, tire inflators are designed to automatically depress the pin and open up the airway as you connect the air hose to the valve stem.
When it comes time to install Slime tire sealant into your tires, valve cores are easy to remove, and just as easy to insert back into the valve stem. Simply use the Valve Core Removal tool in the black cap of your sealant bottle to screw out/in the valve core.
Congratulations, you are now an expert in valve cores!