Air Filter

2021-10-21 18:44:00 / / Comments 0
motorycle airfilter air-filter descripton and faults

Air filter


Air filters are indispensable for the operation of cars and motorcycles, e.g. they protect the engine from contamination.
Air filters can be differentiated according to their operating principle and the medium to be filtered.
The quality feature of good filters is high filter performance with the lowest possible back pressure.
Long service lives before filter replacement are also desired.
The air filter has the task of cleaning the intake air of the engine.
Without an air filter, the smallest suspended particles of the fresh air drawn in would form an abrasive mass together with the engine oil, resulting in severe wear on pistons, cylinders and the valve guides.


Dry air filter


Dry air filters are often used as filter elements.
The fresh air flows through the filter elements.
From the dirt load of the fresh air and the air filter size of the paper area depends on the possible duration of use.
This type of filter consists of annular-cylindrical or rectangular-flat structure.
The zigzag folded paper-like fabric of the air filter, increases the filter area.
Thus, it reduces the flow resistance for the sucked fresh air and increases the usage time.
In the ring filters, the dirty air outside the cylinder is cleaned by the air filter and the then clean air inside the ring filter cylinder is sent to the engine.

Flat air filters are another commonly used variety of air filter types.
This filter is fixed in the air filter box in a frame.
The air flow is sucked through the zigzag pleated mesh, thereby cleaning it.
Over time, the screen filter becomes dirty and the flow resistance increases.
Therefore, they must be changed regularly.


Performance losses and faulty engine combustion are imminent because not enough air can be drawn in.
These air filter inserts are used only once and must be disposed of after use.
The advantage of these dry air filters is their simple and inexpensive production.


Foam dry air filter

Foam layers are used in this type of filter instead of the folded paper.
Advantages of this construction of the filter is the higher air passage and the possibility of cleaning, which allows a longer service life.


The lower filtering effect compared to the paper filter is compensated by thicker foam layers.
The filtered dirt cannot be completely removed by cleaning and the filter becomes more and more clogged and must also be replaced at some point.


Also, the foam is not durable.
The filter elements dissolve after a certain time, which also requires replacement.


Permanent filter

Replacement air filters are offered for many car and motorcycle models to replace the original air filters.
The manufacturers advertise up to 100 000 km without cleaning for these duration air filters.
After cleaning and new oiling, these can be used again.
The structure of these air filters is realized with oiled cotton.
In the case of carburetor engines, due to the greater air flow of the air filters, the mixture setting of the carburetor must be adjusted.
In the case of injection with air flow and mass meters, manual readjustment is not necessary.


Effect of filters


Screening effect

Contaminants are retained in filters by passages of smaller mesh than the dirt particle size. Sieve or fiber filters are the most common types of filters and are inexpensive to manufacture.


Adhesion

A filter built up by oil-finished metal mesh realizes the filtration of fresh air flowing through it.
The impurities are filtered out by adhering to the oil film.
This type of filter is maintenance-intensive due to regular renewal of the oil film and has been used on older motorcycle and moped models.


Magnetic effect

Magnetic filters are mostly used for supportive filtration.
Ferrous impurities are removed.
Magnetic filtration is used in oil and hydraulic filters.


Centrifugal effect

When the intake air is set in rotation, the impurities in it are pressed by centrifugal force to the edge of the filter and deposited there.
This type of filter is easy to clean but complex in design.


Other filter types are e.g. cyclone filters, centrifugal separators, liquid filters, oil bath air filters, oil-soaked air filters...

Find your air filter for your motorbike model here