There are two main types of fuel pumps: mechanical and electrical. Mechanical fuel pumps use engine camshafts to drive diaphragms that push fuel through the pump, while electrical fuel pumps use electric motors located inside or inline with the fuel tank to draw and pressurize fuel for modern fuel injection systems. Within electrical fuel pumps there are in-tank and inline subtypes. Turbo pumps can also be used to further increase fuel pressure for high-performance engines.

1. Types of Fuel Pumps

2. Fuel pump is an essential component of any internal combustion
automobile engine. It serves as the mechanical heart of a car and
maintains a steady flow of fuel from car's tank to its engine.

3. Generally, a carburetor that uses air vacuum is enough to direct
fuel to the engine. However, a fuel pump does function more
efficiently and can help the carburetor to do its job better. This
article will discuss what a fuel pump is precisely and types of
fuel pumps.
There are two major types of fuel pumps - mechanical and
electrical fuel pumps.

4. Mechanical fuel pump: Mechanical fuel pumps came before
their electrical counterpart. They are referred as diaphragm
pumps.
• Agravity free fuel pump is located on the head of the cylinder
or on the engine block, and a camshaft regulates it by moving
the pump's lever up and down.
• Car engines with carburetor use mechanical fuel pumps to
drive the fuel from the tank to the fuel bowl of the carburetor.

5. • As the cam shaft clicks the lever, the lever in turn forces a
spring that sets other springs in motion till the diaphragm is
forced down the bowl of the pump, increasing the level of fuel
in the pump's fuel bowl.
• The pressure of the diaphragm enables the fuel to move up
and out of the pump through an outlet. The fuel then gushes into
the carburetor.
• There is a check valve at both the outlet and inlet parts to
make sure that the flow is unidirectional.
• Amechanical fuel pump operates at a pressure about 4-6
pounds per square inch.

6. Electrical fuel pump: This type of fuel pump is present in
modern cars. An electric fuel pump operates at a pressure of 30-
40 pounds per square inch.
• They utilize the fuel injection systems to spray the fuel
directly into the engine instead of allowing it to flow from the
carburetor.
• This method is not only faster but also more fuel efficient
because the injection system can control the flow of fuel that
goes into the engine.

7. However, this fuel system needs to draw the fuel from the tank
at high pressure.
• The electrical fuel pumps consist of an electric motor
connected to pump that aids to suck out the fuel and pump it to
the engine.
• Nevertheless, having any electrical component close to the
combustion engine can be dangerous as there's a probability of
gas vapors escaping and even a small spark could cause a fire.
Hence, electrical fuel pumps are located inside the fuel tank
itself - submerged in the fuel to keep it cool and prevent it from
excess heating.

8. There are two subtypes of electric fuel pumps:
In-tank electrical fuel pump:As the name suggests, an in-tank
fuel pump is located inside the fuel pump.
• Placing a pump inside the tank makes it less likely to handle
gasoline vapors farthest from the engine. Also, it is less prone to
start a fire.

9. Inline electrical fuel pump:An in-line fuel pump is connected
to the fuel line while being wired to the battery.
• This type of fuel pump, which is tubular in its structure,
contains several pumping systems.
• During the transfer of the fuel from the tank to the engine, the
fuel from the tank is taken inside the pump.
• Amesh screen filters the residue (if present in the fuel) before
sending the fuel to the metering pump.

10. • The metering pump then pushes spins and scrambles the fuel
to generate high pressure.
• The process dilutes and separates the fuel to make sure that it
meets the standards before being pumped into the fuel rail
through the fuel line.
• Here the fuel is sprayed as a fine vapor into the cylinder's
intake chamber through a tiny nozzle.
• With advances in technology, an in-line fuel pump is made to
be placed outside the tank without the risk of flaming.

11. Turbo pump: Aturbo pump is devised to increase the pressure
of the fuel with the goal of increasing engine's performance and
power.
Applications of these pumps include rockets and other high
powered vehicle engines.
Turbo pumps include certain kind of driving turbines combined
with rotor-dynamic pump.

12. Regardless of its potential uses, they are often considered
challenging to design and loss of efficiency is considered to be
common.
Fuel is pumped into a chamber where it is forced to a higher
pressure by the blades rotating along an axis.
Possibly, turbo pumps are designed with different shapes to
promote increased pressure and delivery of powered fuel to a
specific location.

13. Two major designs are used to create turbo pumps:
• Centrifugal: In this the fuel is injected along an axis and the
spinning rotors force the liquid to the edges of a widening
diffuser.
• These types of designs can produce the highest pressure
because of the unrestricted flow of liquid through the diffuser.
• Significantly, a centrifugal pump might be seen in vehicles
that require a great deal of power, such as tanks and rockets.

14. • Axial: This type of pump usually produces greater efficiency
with lower pressure.
• The difference with the centrifugal design is that the rotating
blades force the fuel towards a particular location rather than
depending on centrifugal forces.

15. • Axial flow pumps combined with other pumps is considered
easier to utilize and design in machines that don't require large
amounts of pressurized fuel.
The pump is the stimulant that sets the fuel running. So,
choosing the right fuel pump contributes a great deal to the
engine's performance efficiency.

16. Airtex Fuel Delivery Systems is the leading aftermarket supplier
of mechanical and electric fuel pumps and modular reservoir
assemblies (MRA). For over 50 years, theAirtex brand has been
the benchmark of cooling and fuel delivery system components
for leading companies in the automotive aftermarket. If you are
looking for either an electric fuel pump or a mechanical fuel
pump, visit us at:Airtexproducts.com.