How Do Valve Cover Breathers Work?
How Engines Work Valve cover breathers are located on top of the valve covers, in the oil-filling hole. They come in different sizes and shapes. To understand the operation of valve cover breathers it is important to know why they are used in the first place. All engines, being internal combustion mechanisms, are subject to thermal contraction and expansion. Even the earliest engines were recognized as having these characteristics, and planning and development had to address this phenomena into its design. Without this taken into account, the engine would suffer catastrophic failure as the engine’s internal components expanded farther than the clearances and began to seize up. When an engine is cold, all the components are contracted, or smaller in dimension, than they will be when they heat up. The pistons and rings in the cylinder block are quite loose when the engine is started. There is significantly less available power, because a good percentage of the combustion will get past th
