What Makes
Hirth Engines Different?
When initially
looking at the Hirth Aircraft engine line, it
may at first appear that Hirth engines are more
expensive than equivalent engines from other
sources. We would like you to consider the
1000hr rated TBO, one year warranty, superior
reliability, and the lower RPM operating range.
Over the long run you will find that Hirth
engines can actually turn out to be the least
expensive choice.
There is an old
saying that goes like this. "Horsepower sells
engines but torque moves the plane". A superior
torque curve brought in at substantially lower
RPMs is why the Hirths outperform other brands
by a wide margin.
Most engines in
the light aircraft market were designed for a
specific use on the ground and then altered to
be used in aircraft. Hirth engines are designed
specifically for aircraft use. Hirth does not
make snowmobile, water craft, or car engines and
then try to modify them for aircraft
applications. Hirth knows that in order for a 2
cycle engine to perform properly in aircraft
use, peak power and peak torque have to be
achieved at lower RPMs. The engine has to have a
realistic TBO and not use complicated rotary
valves. The use of Nikasil cylinders and
Hyper-Eutectic Aluminum pistons make Hirth
engines very seizure resistant. Our red line CHT
is 535F, our redline EGT is 1256F. This gives
Hirths good fuel efficiency and a very clean oil
burn. The use of chrome moly steel crankshafts
insure long life with little chance of failure.
It costs more to build an engine when you use
the best technology and materials available but
in the long run you will find that Hirth is the
better value.
Quality Design
The two most FAQ's
about Hirth engines are: how they are able to
produce superior performance at lower RPMs than
other two-cycle engines, and how the 1000 hr
rated TBO is possible in a two-cycle. Hirth has
redesigned the porting and the combustion
chambers on their aircraft engine line to
produce a higher peak hp and torque at lower
RPMs. Please understand, this, not the peak hp
and torque output possible overall, but rather
the best output possible at a more usable RPM.
Midrange throttle control and fuel use are also
improved as a result. Porting and combustion
chamber design are very important to "tuning" a
two stroke engine for the application in which
it will be used. This line of Hirth engines have
been "tuned" for flight. So, now the RPMs are
down, but the good engineering doesn't stop
there. Hirth uses two substantial ball bearings
on the drive(PTO) end of the crankshaft. High
strength chrome moly steel crankshafts are used
instead of the softer carbon steel cranks. All
engines come standard with special hypereutectic
alloy pistons and Nikasil cylinders.
Let's talk
about cylinders
Most engines on
the market today are built with steel sleeve
cylinders. Although steel sleeves are less
expensive than Nikasil, steel cannot dissipate
heat as efficiently as aluminum and expands at a
slower rate. As the heat in a steel sleeve
cylinder engine increases the piston expands
faster than the cylinder wall, steadily
decreasing the piston clearance. To compensate
for this, engines utilizing steel sleeve
cylinders, must run lower CHT and EGT
temperatures. Hirths' cylinders are of aluminum
alloy; there are no sleeves. The cylinder walls
have been treated with the patented Nikasil
process. Nikasil coated cylinders have a
hardened surface that cannot peel and is more
wear resistant than steel sleeves. Because the
cylinders are still an aluminum alloy, their
expansion properties as well as their excellent
thermal conductivity are virtually unchanged.
This design allows heat to be dissipated quickly
and efficiently. The piston is also made from an
aluminum alloy. The piston alloy is slightly
different and expands slightly less than the
Nikasil cylinder. This combination of cylinder
treatment and matched cylinder and piston
materials creates an extremely seize resistant
environment. This is also why Hirth engines can
handle cylinder head temperatures of over 600
degrees F. without failure. Although the Nikasil
process is very expensive, the resulting
increase in the engines life span, performance,
and reliability more than offsets the cost.
Philosophy
K.I.S.: Keep it
simple is the rule at Hirth. If it isn't there,
it can't break. Hirth does not use performance
enhancers such as Dyke rings or rotary valves.
These are all mechanical devices and if they
fail you are coming down. They all require
additional maintenance and add to your
preflight list. If Hirth ever does offer such
technologies it will be because the benefits
far outweigh the costs.
Hirth has designed
an entire line of aircraft engines from 15 to
110hp. All engines include the following as
standard equipment: Carburetor(s), Air filter(s),
Spark plugs, Starter relay, Regulator/Rectifier,
Fuel Pump, Nikasil cylinders, Chrome moly steel
crankshafts, Dual oversized bearings on PTO
side, Hyper-Eutectic pistons, Complete exhaust
system and Dual CDI ignition with electronic
advance. (F36 15hp engine only available with
single CDI
-
Hirth G-40 Gear Box available
in 2.03:1, 2.25:1, 2.64:1, 2.96:1 and 3.33:1
Ratios. Used on F-30, F-23 and 3701 engines.
-
Multi-groove
Belt drive: Single wide belt with multiple
grooves. Available in 1.8:1, 2:1, & 2.5:1
Ratios. Can be used on all engines up to
50hp. Drive wgt. approx. 15 lbs. depending
on ratio.
-
Recoil start
is available on all engines except fan
cooled F30's and 3701 engines.
-
Engines can
have both recoil and electric start
installed.
-
All engines
can be ordered without electric start.
-
Hirth engines
carry a full 1 year warranty (parts and
labor) and a rated 1000 hr. TBO. 1200 hr.
TBO on special high torque/low Rpm engines
2702, 3202, 3701-80Hp and F30-80Hp.
-
Hirth engines
are engineered and manufactured in Germany.
-
Crankshafts
have a pro-rated 3 year warranty, H series
engines used on helicopters have a 1 year
warranty on crankshaft and piston seizure is
not covered. F36 warranty is 6 months.
The Hirth
heritage
Hirth was founded
in 1917. They built 4 cycle aircraft engines for
the German airforce until the end of World War
II. After the war they were forced into the
ground engine business and eventually developed
a line of snowmobile engines in the 60s. Hirth
built their last snowmobile engine in 1974. The
company was taken over by the Gobler Co. and the
decision was made to combine the aircraft
technology with what was learned in the
snowmobile industry to develop 2 cycle engines
for use in aircraft. The result is a line of 2
cycle engines that are much more advanced than
standard ground engines. In an aircraft this
means stronger climb and cruise at lower RPMs.
It means less noise, vibration, and fuel use.
Less likely to seize a piston or break a
crankshaft.
Quality
Support
While the quality
and design of the engine is of course important.
After-sale support of the engine is of equal
importance. Recreational Power Engineering has
developed the most comprehensive support system
in the industry. Engines are warranted for a
full year plus a 3 year pro-rated crankshaft
warranty. Warranty not only covers defective
parts but also labor, free tech support, and
prepaid return shipping of the engine. These are
all unprecedented support features.
NOTE: Hirth
engines are manufactured on a limited basis.
There can be a 4 to 6 week lead-time on some
models. It is best to get your order in well
before your kit is complete to avoid waiting on
your engine. 50% down is required to order.
Hirth Aircraft
Line
All Hirths have
Al-Nikasil coated cylinders for superior
performance and reliability. Al-Nikasil in
simple terms is a nickel based material, applied
in a paste form. When super heated it becomes
part of the cylinder itself. Al-Nikasil provides
for a super low coefficient of friction allowing
Hirths not only to produce more hp than our
nearest competitor but also to run with greater
efficiency and reliability.
Hirths crankshafts are 4130 chrome moly steel.
Heads, rings, block casting, connecting rods and
associated components are all of the highest
grade alloys available today.
F-33 2 cycle
28hp and F36 15hp.
The F33 and F36 engines are some
of the lightest single cylinder engines you'll
find anywhere.
2702 2 cycle
40hp
The 2702 is our small high torque
low RPM engine. Like it's big brother, the 3202
it's a low RPM powerhouse, at an incredible 5500
rpm this little engine is producing 40hp and
it's pumping out 39ft/lbs of torque at only 4500
rpm. The Hirth 2702 is ideal for single seat
ultralight aircraft.
F-23 2 cycle
50hp
If you prefer an opposed cylinder
engine, then this one's for you. F-23 puts out
an amazing 50hp at only 6000 rpm and provides
42ft/lbs. of torque. All with a total weight of
only 87 Ibs. This engine can handle any part 103
ultralight and most single seat experimentals.
Now available with improved belt re-drive and
exhaust system.
3202 2 cycle
55hp
Hirth's High Torque low RPM
engine. The 3202 produces 55hp at only 5500 rpm
while building an impressive torque of 52ft/lbs.
at only 4500 rpm. This low RPM operation equates
to the smoothest and quietest running power
plant you'll will find anywhere. Hirth 3202 the
biggest little engine available.
2703 2 cycle
55hp
The mainstay of mid size engines.
2703 is a product of of Hirth's first designs.
2703's have the highest operational time of any
Hirth engine. This strong light weight performer
will move you to new heights.
3203 2 cycle
65hp
Hirth's most popular engine. The
3203 produces more Horsepower and Torque per
pound then any other engine in it's class. The
Hirth 3203 is the premiere powerplant for the
heaviest of Ultralight trainers and light
Experimentals today.
F-30s 85/110hp
Flagship of the
Hirth product line; the F-30s are available in
two versions, the solid F-30 80hp and the
awesome F-30/2c 110hp. The Hirth F-30s are the
premiere power plants for the Experimental and
Homebuilt industry.
3701 - 3
cylinder - 2 cycle water cooled 80/100hp
Hirth's latest design. 3701's
have a very narrow profile allowing installation
in small cowlings. Very low fuel consumption
rivals similar Hp 4 cycle engines.
