Hot Powder Coating Applications ::
« Back to (Powder Coating Types)
What Should Be Hot Powder Coated?
High temperature coatings have become a necessity in today’s
automotive and industrial marketplace. This process is no longer a
hidden secret that only a few racers and engineers know about. Everyone
from the R.V. enthusiast to the high performance race drivers, aircraft
owners to vintage auto and marine mechanics want the benefits of high
temperature performance coatings.
Exhaust manifolds ::
can either be a cast iron, factory-type manifold or a tube steel header
typically used in performance applications. There are a variety of
reasons for coating an exhaust manifold header. Quality, durability,
life expectancy, and performance are gained through the use of these
Corrosion Protection ::
The manifold will live longer as well as look nicer. Whether it is
for performance or show, coating an exhaust manifold is valuable to
The advantage of ceramic coatings they don’t blue or discolor
like chrome plated exhaust manifolds.
Performance Benefit ::
The coating is a thermal barrier, thus keeping heat within the manifold
or header. There are a number of benefits for this. First, by keeping
heat within the manifold, you're going to accelerate the exhaust gas
velocity which reduces back pressure and reduces fuel contamination
due to reversion. This is a performance benefit.
Surface Temperature ::
Ceramic coating reduces the surface temperature of the manifold. This
means if a person comes in contact with it, they are less likely to
be burned and leave skin behind. If there is a component close to it,
it will not see as much heat as it would with an uncoated manifold.
In addition, not as much heat will be radiated under the hood or into
the engine compartment. This reduces the under hood temperature which,
again, reduces the temperature of surrounding parts, such as, alternators
and starters. It also reduces the amount of heat that can be drawn
in through the carburetor, which is a secondary performance benefit.
There are a variety of colors in thermo coatings that can be used
on exhaust manifolds or headers.
Cylinder heads ::
One of the best applications for Thermo coatings is in combustion chamber
areas. Coating the combustion chamber of a cylinder head can increase
performance significantly. In addition, more compression can be run
as the proper coating will provide resistance to detonation. Tuning
changes can also increase the level of power generated. Coating the
intake and exhaust runners can also impact performance. Coating the
exterior and the area under the valve cover can improve heat management.
By coating the combustion chamber, we reduce the amount of heat that
escapes during the power stroke which means more of the heat generated
is utilized in "pushing" the piston down. The coating also
insulates the surfaces so that they absorb less heat, reducing the
load on the cooling system and reducing the amount of dimensional change
the head may see from the heat it absorbs.
The coating functions in several ways.
1. To keep heat in (Thermal Barrier)
2. To move heat over the surface to reduce hot spots (Radiation)
3. Reflect heat into "cooler" or shrouded areas of the chamber (Convection)
4. The coating retains less residual heat from combustion than other thermal
barriers, thus transferring less heat to the incoming fuel charge (Reduced Thermal
Combining these features increases power levels, reduces part operating
temperature, aids in reducing detonation and can increase fuel efficiency and
reduce emissions. By transferring less heat to the incoming fuel charge detonation
is reduced, as pre ignition which causes detonation, is generally the result
of excessive heat absorption by the fuel as it enters the combustion chamber.
By allowing the heat of combustion to be more efficiently used, the fuel charge
is better combusted, allowing more compression while reducing the fuel quantity
need (in most cases) and increasing power. By accelerating the burn rate of the
fuel, through better heat management, less timing is needed to have the optimum
burn occur at top dead center. There is a standard coating, and as well a coating
recommended for very high compression motors (13:1 and above) or for engines
that have tight quench areas as well as Turbo Charged, Super Charged and engines
utilizing Nitrous Oxide systems.
Coating the ports helps with flow and provides additional thermal benefits.
Coating the intake runner with a Dry Film Coating can reduce fuel drop out while
insulating the incoming fuel from the heat of the head. Coating the exhaust can
improve flow by creating a very slick surface, while reducing the amount of heat
that can pass from the hot exhaust flow into the head. Coating the exterior of
the head allows for faster transfer of the heat that is absorbed from combustion,
into the air flow around the head, thus allowing the head to run cooler. This
will impact the amount of heat transferred to the intake manifold as well as
reduce the heat that accessories will be exposed to, that are mounted on or near
the head. When a thermo coating is applied to the area under the valve cover,
better oil drain back is achieved as well as better thermal transfer to the oil,
which is cooling the head and valve springs.