Exhaust Gaskets

A head gasket is a gasket that sits between the engine block and cylinder head in an internal combustion engine. more...

Home
ATV Parts
Apparel & Merchandise
Automotive Tools
Aviation Parts
Boat Parts
Car & Truck Parts
Air Conditioning and Heat
Air Intake & Fuel Delivery
Brakes
Charging & Starting Systems
Computer, Chip, Cruise...
Cooling System
Decals, Emblems, & Detailing
Emission System
Engines & Components
Exhaust
Exterior
Filters
Gaskets
Cyl. Head & Valve Cover...
Exhaust Gaskets
Full Set Gaskets
Intake Gaskets
Oil Pan Gaskets
Other
Gauges
Glass
Ignition System
Interior
Lighting & Lamps
Other Parts
Safety & Security
Salvage Parts Cars
Suspension & Steering
Transmission & Drivetrain
Turbos, Nitrous,...
Wheels, Tires & Parts
Car Audio, Video
Manuals & Literature
Motorcycle Parts
Other Vehicle Parts
Personal Watercraft Parts
Racing Parts
Services & Installation
Snowmobile Parts
Vintage Car & Truck Parts
Wholesale Lots

Its purpose is to seal the cylinders to ensure maximum compression and avoid leakage of coolant or engine oil into the cylinders; as such, it is the most critical sealing application in any engine, and as part of the combustion chamber, it shares the same strength requirements as other combustion chamber components.

Head gasket types

MLS - stands for "Multiple Layers Steel,". Most modern head engines are produced with MLS gaskets. These typically consist of three layers of steel.;

The contact faces are usually coated with a rubber-like coating such as Viton that adheres to the cylinder block and cylinder head respectively whilst the thicker center layer is bare.

Solid copper - A solid sheet of copper, and typically requires special machining called 'o-ringing' that places a piece of wire around the circumference of the cylinder to bite into the copper. When this is performed copper gaskets are extremely durable. Recently companies have started producing copper gaskets with integral sealing wires permitting their retrofit into engines without the removal of the engine block for machine work.;

Composite -- an older technology. Typically these are made from asbestos or graphite but are more prone to blowouts than newer gaskets. Asbestos gaskets are becoming increasingly rare due to health concerns.;

Gasket problems

Occasionally, the compression in the cylinder will cause a leak to form in the gasket and the gasket will have to be replaced, or severe damage can take place (a "blown" head gasket). This problem has been exacerbated by the use of aluminum rather than iron cylinder heads; while lighter than iron, aluminum has a much greater thermal expansion rate, which in turn causes a great deal more stress to be placed on the head gasket. Engine makers have responded to this by adding a non-stick coating such as Teflon to the surface of the head gasket.

If the gasket fails, a variety of problems can occur, from compression loss (leading to power reduction, or a rough engine), to exhaust gases being forced into the cooling system, leading to the engine overheating and increased engine wear due to the motor oil being mixed with antifreeze. Coolant can leak into the cylinders, causing the exhaust to issue steam and the catalytic converter to be damaged. If a very large amount of coolant does this, hydrolock can occur, causing extensive engine damage. Sometimes, all that may happen when a head gasket is blown is excessive steam erupting from the tailpipe and the engine may act and drive like normal.

Read more at Wikipedia.org