Just so you all know, this place is extremely good, before I decided on
their coatings I grilled them on technical things for a few weeks, and
they answered all of my questions, I had them do the following:

Thermal barrier coatings on:
tops of pistons
combustion chambers
exhaust ports
exhaust manifold
turbine housing
o2 housing
downpipe

oil attracting lubricating coating (maintains oil film)
sides of pistons
valve springs
transmission gears
xfer case gears
rear diff gears

their prices aren't that bad, and turnaround is fast

While it may be difficult to quantify what "gains" this stuff gets you,
I have seen numerous studies that show that the gains are more in the
longetivity area.

For instance coating a gear may not increase its peak torque handling
capability, but since gear failure is due to fatigue, by reducing
friction (and thus heat), the fatigue lifetime of the gears is increased
substantially--over 300% in some cases.

Its easy to misunderstand what the thermal coatings are designed to do,
while its true they are insulating, they are also very thin...so how can
it help?

Lets put it this way, these coatings have about 1/400th the thermal
conductivity of steel, and 1/1200th that of aluminum... so a 2 mil
coating thickness is equal to 0.8" of steel or 2.4" of aluminum...
Also, the emissivity of the coating can either be much higher than metal
(which is ~0.2 for polished to 0.8ish for rough oxidized) or much lower
(typically

Lets look at two different cases, an exhaust manifold runner and a
piston top.

In the manifold runner, you want to reduce the heat transferred to the
air (decreasing the temperatures in your engine bay)

Normally, lets say you have 900 C EGT and the manifold is at say 500C on
the outside (faint red-hot). Assuming a 2" manifold tube, a surface
with an emissivity of 0.8 will emit about 42 W per inch of tube. If the
tube is about 0.2" thick and made out of iron, the temperature
difference from the inside of the tube to the outside would be about
3.5degC.

By applying a 0.016" thick (16mil) coating of ceramic with a 0.4
emissivity and the thermal conductivity shown earlier, the effective
thermal conductivity of the tube drops to 1.2 W/mk (factor of 33
reduction), the emitted power drops to ~30W/inch and the tube is now
527C on the outside and 616C on the inside (its actually hotter even
though its emitting less heat).

With a 0.8 emissivity coating the heat is ~34W/inch and the outside tube
temperature is 457degC (inside tube temperature 562degC)

Note how in either case the inside of the tube is actually hotter.
Benefits are:
Given that a manifold has at least 20-30" of runner length (not even
including the collector areas), this means the difference of 200-300W of
heat being retained in the exhaust alone (roughly 1/3rd to 1/2 a
horsepower of exhaust energy). Since the exhaust energy is roughly
equal to the engine output, on a 400hp motor this is ~0.1% improvement
in exhaust energy...which doesn't seem like alot, but that is just the
tubes of the exhaust manifold...including the collector area and turbine
housing the horsepower regained is in the 1-2 range (0.25 to 0.5%),
including the downpipe that number increases (even though the dp is
colder, it has a MUCH greater area...and its not that much colder
100-200degC max meaning it puts out roughly the same heat / unit length
as the exhaust manifold pipes)...so you could easily get 4-5hp of heat
that would normally go into the engine bay air into the turbo
instead...that's a 1% improvement in exhaust energy for free.

Also, since the overall heat being transmitted through the steel is
less, the temperature difference from the inside to the outside of the
pipe (not including the ceramic) is also less...meaning less thermal
fatigue (by about 3-5% less strain in the pipe).

Also, while 1-2hp of heat doesn't seem like alot in the exhaust energy
area, think about it this way, to cool a motor producing 400hp, you need
about 4000CFM of airflow through the radiator. Say 80% of this air
leaves immediately, and 20% is stagnant in the engine bay, that 4-5hp of
heat would increase the air temperature in the engine bay by ~5degC
(9degF)...


Now the other case, for the combustion chamber or piston, what the
coating is doing is two things. First it is insulating (applied ~2mil
thick) AND it has extremely HIGH emissivity (~0.95).

What happens here takes place extremely rapidly, during the combustion
stroke, the surface of the coating is heated to an extremely high
temperature (actually higher than an uncoated piston) since the heat
can't easily flow into the piston or combustion chamber. While this may
seem like a bad thing, the important part is that since the heat doesn't
easily flow into the metal underneath, and the fact that coating is so
thin means the overall amount of heat that goes into the coating is very
small. During the exhaust and intake strokes, the high emissivity
coating quickly cools down (since its emitting much more heat per unit
area and the overall amount of heat is so small) so the coating is
actually cooler than an uncoated metal wall by the time the compression
stroke starts...meaning less hot-spots, and less detonation!

The side effect is, since the metal walls absorb so much more heat than
a coated one, the overall heat the engine dumps into the coolant is
drastically reduced.

Think about it this way, imagine the heat flowing into the wall of the
combustion chamber. When the air/fuel mixture first ignites, the wall
is cold, but the gasses are hot, so surface of the wall heats up--this
heat is then diffused deeper into the wall. The speed at which the heat
moves into the wall is governed by the conductivity, and the specific
heat...the higher the conductivity, the less temperature difference it
takes to move a given amount of heat into the wall, and the higher the
specific heat, the more heat is needed to raise the temperature of the
material a certain amount. While aluminum has a high conductivity
(100-1000 times more than the ceramic) the ceramic has about double the
specific heat. This means that the heat will move into the aluminum
more than 100 times faster. Since the combustion process only lasts a
few thousandths of a second, the overall heat that goes into the aluminum
is much higher, so by ceramic coating the piston and combustion chamber,
less heat is lost to these parts, meaning more heat in the exhaust and
less in the engine--so you get faster spoolup (more exhaust energy),
less overheating issues, and the parts all stay a little bit cooler,
which means longer lifetime

Add that to drastically reduced detonation and the price seems much more
attractive--coating chambers and exhaust ports on a head costs $200
bucks and piston tops are between 10 and 20 bucks each.

Cheap insurance :)
___________________________________

Marc V Berte

President

Horizon Defense & Aerospace Solutions Inc.