Characteristics and use of engine gaskets

Posted by Ajusa: February 7th, 2018


In an engine there are several types of gaskets with multiple applications. In this article, AJUSA explains you the function and the use of the gaskets in an engine.

 Whenever the fixed parts of an engine are disassembled, all the gaskets that remain  at sight must be replaced.


 What is a gasket?

A sealing gasket is a piece that is located between two parts of the engine to achieve a good fit and avoid the loss or entry of fluids (oil, water, coolant, fuel, etc.). In the engine, you can find different types of gaskets: cylinder head gasket, valve cover gasket or oil seal, among others.

Since 1973, AJUSA manufactures cylinder head gaskets and full sets, guaranteeing  OE quality and complete coverage. At present, AJUSA has the  most complee catalog of the aftermarket, exceeding 100,000 references.


Gaskets function

The main function of the  gasket is to guarantee the tightness of the  engine and to avoid leakage of liquids or combustion gases.


The gasket joins  irregular surfaces (we speak in terms of millimeter microns). For this reason, it is necessary to interpose between both surfaces a softer material, such as a fiber or an elastomer, which is able to adapt to  those imperfections, ensuring a perfect sealing.


In this way, money is saved in the machining of joining surfaces. The gasket corrects the possible irregularities of the machining. Therefore, although the leaks are microscopic, if we did not use gaskets, our vehicle would break down.


One of the most important gasket is the cylinder head gasket because it unites the main parts of the engine: the block and the cylinder head. This part works in the most  critical sealing area of the engine. A cylinder head gasket have to withstand combustion temperatures above 1,100 degrees Celsius and pressures above 250 bar.


AJUSA leads the  manufacturing of cylinder head gaskets in the world, as it offers full coverage for cars, commercial and heavy vehicles, both from European and Asian manufacturers. CATALOG


Various materials can be used in the manufacture of gasket: rubber, silicone, metal, cork, fiber or polymers. The guarantee of the sealing depends on the quality of the gasket and if the installation  is professional or not. The quality of the AJUSA cylinder head gaskets is international, both due to the exhaustive quality control of the materials used and their meticulous production process. The AJUSA catalog, with more than 100,000 references, can be downloaded in PDF through the web or can be consulted online.


Types of engine gasket

The engine is divided into three fixed sections: cylinder head, block and crankcase. Each of the parties uses a type of gasket or sealing liquid. We also find other important gaskets such as intake and exhaust manifolds, water pump, the oil  seal, turbocharger,  valve covers, etc.





Reason for replacing a gasket

Sealing is essential for the proper functioning of the component. A leakage problem can cause significant damage to the internal components of the engine.  See ’The main reasons for failure of the cylinder head gasket’.


When to replace a gasket?

 Whenever the fixed parts of an engine are disassembled, the gasket that remains at sight  must be replaced. 

 When you  replace the cylinder head gasket, it is mandatory to replace the bolts. The bolt is deformed with angular tightening, so it  cannot be reused.

AJUSA offers technical advice to all its customers and users  via the mail: In addition, you will find video tutorials in which a professional explains how to assemble the AJUSA references on a real engine.  VIDEOS


- A gasket must be replaced once disassembled or during maintenance. In the assembly, the gasket suffers deformations and it would cause poor sealing.

- In a review, it is possible to confirm leaks of oil or other liquids. Normally, this oil comes from poor sealing and  the gasket needs to be replaced.

- During a heavy review, it may be advisable to take advantage of the other gaskets. For example,  when replacing   a timing belt, the crankshaft and camshaft seals are usually changed.






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