Powder Coating
Engine Cooling
New Thermostats - USA made
German style
We get all kinds of questions about thermostats and flaps... maybe you are wondering:

What are thermostat flaps anyway?
The thermostat flaps fit up inside the fan shroud on either side and are connected by a linkage to
each other and down to the thermostat which is located between the #1 & #2 cylinders. The flaps
are nearly (but not completely) closed when the engine is cold. When you start the engine, heated
air from around these cylinders causes the thermostat to expand once the air reaches the opening
temperature. This causes the linkage to move and the flaps to open. As the engine temp rises, the
air over the cylinders gets hotter, causing the thermostat to expand more. This is self-regulating,
meaning that when the engine heats up, the flaps expand, and when the engine cools down, the
flaps close.  

It does not get cold where I live, or I only drive in the summer. Do I really need to run thermostat
The point of the thermostat flaps is not to provide cooling. The flaps are there to get the
engine heated up to proper operating temperature as fast as possible and then maintain
that temperature.
This is the #1 misconception about the thermostat and flaps system. Everyone
thinks they are meant to keep the engine cool, when it really is meant to heat it up quickly. But
NO, you are not required to run the thermostat flaps. Many air cooled VW's are running all over
the world, in all sorts of temperatures and conditions with the flaps missing. However, all of those
engines are running too cold at startup. This means that all of those engines have lower fuel
economy (less MPG), more engine wear, and resulting shorter engine life. So, if you are not
concerned about those things, you don't need thermostat flaps.

Can the flaps get stuck closed, causing the engine to overheat?
Nothing is impossible, so yes, they could get rusted closed or hung up in the closed position,
which would result in an overheated engine. However, I have rebuilt 100's of thermostat flaps and
only seen three that were rusted shut. With a fresh blasting and powdercoat, you should be fine
for many years to come.

Can the thermostat get stuck closed, causing the engine to overheat?
The German thermostats are fail safe, meaning that if they fail, they SHOULD fail in the full open
position, giving you maximum cooling. I have seen 100's of thermostats over the years, and I have
only seen three that were contracted that did not expand when heated. So it is possible, but it is
not very likely.

The VW Mexico version of the thermostat is NOT fail safe, meaning that if the wax inside leaks
out, it will stay fully closed. However, I have never actually seen a failed thermostat of this style,
nor have I heard of any of them failing, so it must not be very common.

How does the thermostat work anyway?
The German units have a small amount of liquid inside that expands when heated. The bellows
are held closed by the partial vacuum inside the sealed unit. As the stat is heated, the liquid
vaporizes and the bellows expands. When the stat cools off, the vapor returns to liquid and the
bellows contracts. If the liquid ever leaks out, the bellows will expand, causing the flaps to go full
open. This is why the German stat is considered fail safe.

The Mexican units have a small amount of wax inside that expands when heated. The unit is held
closed due to a large high tension spring. As the stat heats up, the wax expands, extending the
stat. When the stat cools off, the wax is compressed by the high tension spring. If the wax ever
leaks out, the stat will stay in the closed position. This is why the Mexican stat is NOT considered
fail safe. I guess you would call that fail unsafe.

Why do you offer two different types of thermostats?
It depends on what the customer wants and his/her budget. The new units are the only ones that
come with a warranty. Also, if you are running an after market "tucked up" exhaust, such as the A1
Sidewinder, the German stat will hit it, so you have to run the Mexican one.

At what temperature does the thermostat open?
It depends on which thermostat you have:
German stat for early 36hp type I carb engines, "stale air" 75-80C opening temp
German stat for type I carb engine, starts to open at 65-70C (149-158F)
German stat for type I FI engine, starts to open at 80-85C (176-185F)
German stat for type IV carb and FI engines, and 4 cylinder Porsche 912 and 914 engines, starts
to open at 85-90C (185-194F)
German stat for Porsche 356, these engines do not have flaps, the stat opens ductwork to run
heated air to the carb intakes (23-34C)
new VW Mexico - this is a real mess, as it comes in both the 65-70C range and the 80-85C range,
yet somehow has the same part number? So, what do you got? The only way to know is to test it.

My engine oil temperature is X, so should the flaps be open now?
Both the engine oil temperature and the temperature of the air coming off the cylinders are due to
the heat generated by the engine running. But there is not a direct connection. Don't try and use 1
to determine the other.

I drove the car for five minutes and the flaps are not open yet. What is wrong?
The flaps are still closed because the engine has not heated up yet. The minimum temperature
the thermostat has to see is 65C (149F) - it just has not gotten that hot yet.

Do I have to run all the lower cylinder tins (heater box sled, #2/#4 air deflectors, industrial shields)
or can I leave all that off?
You MUST run all of the lower engine tin when you are running a thermostat. If you do not, then
cooler air from below the car will mix with the heated air from you engine. This will result in the
stat not opening the right amount, or even keep it from opening at all.
This is super important! If
you are not running heater boxes, then you need to run the industrial shields to fill in this open

I have a VW type IV or Porsche 356, Porsche 912 or 914 engine. Can I run a bug thermostat on
it? They look the same.
They look the same, but the type IV opens at a higher temperature.

Can I run a Corvair thermostat on my bug engine? They look similar.
The Corvair stat opens at 85-90C, which is too hot for a bug engine, but would work for the type
IV, Porsche 912 and 914 engines. But the fittings on both ends are wrong. You would have to
make some sort of adapter.

Will a bug thermostat work on a Porsche 356?
No, the Porsche 356 thermostat is a much lower temperature. There are no flaps on the 356
engine. This stat opens ductwork for warm air to go to the carburetor intakes, a totally different
100% Brand new, USA made, 2
year warranty - $119
65-70C for carb opening range or
80-85C for FI opening range
can change based on supply, getting very
hard to find now

Each unit is tested, and it might work or
years,,, or might fail next week. There is no
way to tell. They are at least 35 years old
I rarely have these in stock, they are getting
more and more uncommon go fin.
This stat requires a modified
thermostat bracket.

It also uses a 12mm wrench to install
instead of a more typical 13mm.
Copyright 2009- 2019 Awesome Powdercoat LLC
GERMAN style type IV,
Porsche 914 and late
Porsche 912 thermostat -
with a 2 year warranty - $134

86-90C opening range

Add a brand new cable for
$10 if needed.
100% new, USA made,
GERMAN style Porsche 356
and early Porsche 912
thermostat - with a 2 year
warranty - $159

23-34C opening range
Each thermostat is
stamped on the
bottom with the temp
range, USA, and the
Awesome Powdercoat
LLC logo.
Parts needed to make
1 thermostat.
To contact us, Email
click here to read an
independent writeup by
a customer that
installed the type IV stat
To contact us, Email
BUG thermostat flaps and
related items
65-70C opening range, brand new, bug,
beetle, ghia, (63-74) & early bus (58-71)
thermostat flaps reproduction of VW part #
111 119 159A $119+ $10 shipping to lower 48
80-85C opening range, brand new, FI bug
only (75-79)
with thermostat flaps reproduction of
VW part #
111 119 159A $119+ $10 shipping to lower 48

while we try to keep 1 in stock, we may need to
make it for you.
75-80C opening range, brand new, 36hp engine,
52-57 with adjustable venturi temperature control,
reproduction of VW part #
111 119 159
$119 + $10 shipping to lower 48 states
Porsche 914 / Porsche 912 / VW
Type 4 thermostat flaps and related
85-90C opening range, brand new, type iv
(68-74), late bus (72-83), porsche 914 (70-76),
late porsche 912 (68-69 & 76)
VW part #
021 119 159A
$134+$10 shipping to lower 48 states
85-90C opening range, brand new, type iv
(68-74), late bus (72-83), porsche 914 (70-76),
late porsche 912 (68-69 & 76)
VW part #
021 119 159A + cable
$143+$10 shipping to lower 48 states
Porsche 356 and Porsche 912
23-34C opening range Porsche 356 thermostat, brand new,

$179 + $10 shipping to lower 48 states.

While we try to keep 1 in stock, we may need to make this once you order.
Brand new type iv stat bracket + special mounting
washer $34 + $6 shipping to lower 48 states.
Brand new type IV pulley, with actual bearing, washers,
and special mounting bolt. $40 + $5 shipping to lower 48
To contact us, Email
USA, complete
Type IV flaps
assembly, $150 +
$15 shipping to
lower 48 states.  

on the shroud that the horizontal bar of the flaps linkage clicks into.
These are brand new,  made in the USA, 3D printed high grade
plastic, not some cheap resin casting. $20 + $3 shipping.