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The Importance of Head Gaskets

The Purpose of Gaskets –

The simplest parts of an engine are its gaskets that fit snugly between metal parts. Though they do not have any moving parts and are made by a stamping machine, they are one of the most critical components of an engine. From the very first moment an engine is started, it begins to wear out due to stress and friction. To protect engines, lubricants are added to allow metals to move against each other. Without the lubricants, heat would build up between the metals causing them to melt and weld to each other freezing the engine.

When an engine is started, the crank shaft is driven by the explosion of gasoline in the cylinder that is fed fuel by the intake valves, which are turned by the cam shaft. The number of revolutions of the engine is measured by the tachometer. Circulating through the engine is a specially designed fluid, or coolant, that keeps the engine at a constant temperature since the explosions and movement of pistons discharges a tremendous amount of heat. Resting under the crank shaft is a pan of oil that circulates as well to keep metal parts lubricated and moving smoothly. The three fluids – gas, coolant, and oil – are essential to the smooth operation of an engine and need to be kept from leaking out. The job of gaskets is to form a barrier between engine parts and keep fluids contained.

Why gaskets are needed -

There have been engines built without gaskets that were precisely constructed with grooves that forced the components to fit together very tightly. The limitations of the engines was the amount of horsepower they could produce since increased heat would loosen the seal between parts.

If the tightest and best machined screws were used to attach engine parts, they would not be able to keep the fluids from leaking. Engines are living moving things that get jostled and bumped. For a short while, the screwed connections would remain secure. Over time, they would be loosened by the movement of the engine, which would lead to leaks. This is why precisely placed gaskets are such a necessity.

There has been the notion that engine parts could be sealed by a sealant. Sealant can be damaged by engine oil and end up on the walls of the cylinders while gaskets are coated with an oil resistant material and maintain their seal. The installation process for sealant can take up to two days until it is completely set. The time it takes to install a gasket is how long it takes to place in the engine.

In simple terms, carefully designed and crafted gaskets are able to protect an engine and keep it from leaking, overheating, and experiencing friction. Specially designed for a specific function, they fit exactly into their place between the two parts they are protecting. In many ways, these simple pieces of rubber, plastic, silicon, or cork can do a job that many metals can’t.

The head gasket -

The king of the engine gaskets is the head gasket that fits over the top of the engine between the engine block and cylinder heads. Head gaskets are designed to withstand the tremendous pressure produced by engines. As fuel economy and performance have become essential features of cars, the amount of pressure produced keeps increasing putting a great deal of stress on engine components. This is especially true of the head gasket. To meet this demand, engineers have taken old versions of head gaskets and updated them using more durable and efficient materials.

Though head gaskets prevent leaks and keep fluids where they belong, they really don’t become important until the engine has run for a while, and engine components begin to wear and lose their strength. A properly installed head gasket is designed to pick up the slack and maintain its seal regardless of the ambient conditions.

The Making of a Head Gasket –

Every mechanic will tell you that people give little thought to a head gasket until it begins to leak. When that happens, the car is taken for repair to have a new one installed. This is where things can get a bit problematic. In modern engines, replacing a head gasket is a very labor intensive job. In most cases, the top of the engine has to be removed to get to the head gasket. A top of the line head gasket can add to the cost of the repairs but is worth the expense when measured against having to have the repairs repeated.

Head gaskets come in a variety types depending on how they are constructed. The old version produced from a simple pressing process has been replaced with more complex versions that are able to take more stress and heat.

Multi-Layer Steel – As the name implies, MLS head gaskets are made from layers of stainless steel with specialized coatings. These expertly engineered and designed head gaskets are embossed so that each layer fits snuggly together and can be secured tightly to the engine block. In most cases, MLS gaskets have three layers, but there are highly sophisticated ones that have four to seven layers.

Copper – Copper head gaskets are used in high performance street engines. The main selling feature of copper is how it distributes heat evenly accounting for any imperfections in the engine surface. Proper installation requires the application of a sealant to ensure a secure fit as well as stainless steel O-rings. Copper head gaskets can be reused four or five times after being properly cleaned.

Composite – Composite head gaskets are the original head gasket that has been used since the invention of the internal combustion engine. The modern version begins with a tanged metal sheet that is covered on both sides with a rolled material to prevent the head gasket from swelling when in contact with engine fluids. Fire rings are built into the gasket as well as other materials to improve the seal to the mounting surface.

Elastomeric – Elastomeric head gaskets have a steel core that is sealed by a silicone synthetic rubber and can be easily matched to any engine design. Their main feature is their strength and ability to withstand extreme temperatures. Elastomeric head gaskets are used with commercial vehicles that are turbocharged and intercooling. They are designed to provide an excellent tight seal in the combustion chamber.

When faced with the problem of replacing a head gasket, it is important to carefully examine all of the options to make the right choice to fit your needs. Licensed repair shops provide helpful advice and guidance regarding this important decision. Knowing all of the possibilities and alternatives can be a great benefit.