4 into 1
Aircraft Exhaust Inc. is one of the only
companies that builds a custombuilt
PVC mock up of the customers design. (See
custom exhaust for all the details)
Our collector
systems are based on equal length
primary tubes (headers). This will get the builder as close to
a tuned exhaust as possible without the use of a dyno.
On a O-360 Lycoming engine with a single
muffler type system, a properly done mock up will produce approximately
14-16 more HP.
In
many ways the choice of the collector style exhaust is getting
free HP! The system is simply making a smooth pulse of exhaust
that goes into the collector, one directly after another, in effect
pulling out the pulse behind it. The theory is very simple, and
very effective if done correctly.
Lycoming engines experience a greater HP output than other manufacturers.
4 into 1’s
(4 cyl) and dual 3 into 1’s (6 cyl) don’t require
a muffler system, this is due to the long length of primaries
from the exhaust flange to the start of the collector (typical
26” -36”) this long run of primaries along with the
collector and tailpipe provide a muffling effect on the exhaust
pulses. Overseas customers might require additional Db reduction
which can be provided by adding an additional muffler just past
the collector. The HP increase due to the collector style exhaust
will be reduced slightly with a muffler but Db reduction will
be what is needed for overseas noise reduction. With a collector
style system the cabin heat is pulled off a straight primary section
over the primary section which provides high temperatures for
good cabin heat. Since the primary is made from stainless steel the high
temps will not hurt the tubing under the muff. In aircraft that
are known to operate in cold conditions we can also add heat pins
to help pull heat from the primary to get even more heat for cold
climates.
The collector type system
is a little more expensive than a crossover, single side stack
or a single muffler system but the great HP gain is well worth
the extra money and time up front.
The system is made of stainless steel tubing (same as all other certified exhaust). With stainless steel, a system can endure higher temperatures, and many more cycles of heating and cooling than mild steel.
We add ball joints on 2 of the
4 cylinders and 2 of the 6 cylinder. This allows a couple of the
cylinders to “free float” and not cause stress on
other primaries or on the collector. Most of the time the collector
has the tailpipe attached and is the end of the system. In most
cases the collector is out on an “arm” which if not
supported properly could lead to premature failure. All kits come with a clamp with a mount so the end of the system can be properly supported. The collector style exhaust has a preset price, and includes one cabin or carb heat shroud, tailpipe support clamps and brackets, collector mounting hardware and links. In some cases there are complex systems, at that time the price will not be set. We will inform you immediatly in this situation. If you wish to have a second shroud for cabin or carb, there will be an additional cost.
AEI builds the cabin and carb heat shrouds
from stainless steel to assure that their will be no failures
due to the extreme heat from the primary in which it is
wrapped around. Carb heat muff
can also be supplied on carburetor engines, this is not included in the standard price. It also mounts on a primary
tube but only requires 4-6” of straight. The carb heat has
a series of holes which draw air from the engine area into the
muff as it is pulled past the primary it is heated and is sucked
into the carb creating carb heat of 95+ degrees over ambient –
(FAA requirement for temp rise for carb heat on certified aircraft).
Both the cabin and carb heat shrouds are 3” OD with a port
in and a port out. Typical scat size for good air flow is 2”.
The collector is held on to the primaries
with a heavy duty link that crosses over the slip joints and bolts
into the welded brackets that are on the two primaries and two
slips on the collector. This is done for many reasons, the installation
requires this type of system and it is also done for inspections
and shipping breakdown.
Contact our sales department to get
more details about your application or to place your order today.
The staff at Aircraft
Exhaust Inc. looks forward to working with you on all of your
aircraft exhaust needs.