Also included in this column:
• Giant OV-10 Bronco
• Ethanol impacts
IT’S NO SECRET that our economy is in a
recession; most of the world is suffering from
the same economic woes. As we tighten our
fiscal belts, the first cutbacks usually involve
discretionary spending. Discretionary income
includes money spent on luxury items,
vacations, and nonessential goods and
services.
For many of our readers, this means
spending less on hobby-related items, but
don’t despair. If you look around, there are
some recession-busting deals to be found. If
you’re in need of a new gas engine for your
latest project, look at the offerings at
Southeast R/C Engines. The company’s line
of XYZ gas engines come complete with
ignition module, muffler, and mount, all for a
great price.
Southeast R/C Engines, located in
Jacksonville, Florida, is the importer and
distributor for the XYZ line of small twostroke,
gasoline-powered power plants. The
company had been searching for small twostroke
engines for use in the radio-control
aircraft. It ordered and tested many types
before discovering the XYZ.
These engines are manufactured to the
highest standards using billet aluminum and
CNC machining to form the crankcase. They
start easily, have very little vibration, and idle
at 2,100 rpm right out of the box.
After running the 50cc engine on the test
bench for more than 10 hours at 3,000 rpm, it
was disassembled to the last nut and found
that it was just starting to break in, and doing
it nicely. It looked great, bearings were fine,
and there were no misalignment marks or
loose bolts. The same procedure was repeated
for the 26cc engine with similar findings.
The 26-C and 50-A are short-stroke, bigbore,
two-stroke designs. Southeast R/C
Engines’ newest offering is an XYZ-50-HP
(high performance).
The 26cc model is compact, has a 45°
offset spark plug, has a Walbro WT-793
carburetor, and weighs 2 pounds, 8 ounces
including muffler and ignition module. This
engine will swing an APC 16 x 8 propeller at
7,600 rpm and is rated at 2.5 horsepower.
The XYZ 50-A has a displacement of 50cc
and is rated at 4.5 horsepower. The street
price for the 26-C is $209.95 and the 50-A is
$259.95. For more information about these
engines, please visit the Southeast R/C Web
site.
Rich Uravitch is a familiar name in the RC
industry. He has more than 40 years of RC
experience under his belt and is a frequent
contributor to many of the current modeling
publications. In addition to Rich’s stint in the
Air Force, his qualifications include editorial
director, editor-in-chief, author, model
designer, design consultant, Top Gun
competitor, and Top Gun craftsmanship
judge.
Rich currently enjoys designing models
that can use an electric power source, because
it offers tremendous potential to Scale
modelers. One of his latest is an International
Miniature Aircraft Association (IMAA)-legal,
81.5-inch-wingspan OV-10 Bronco.
The Bronco is 79.5 inches long and has a
wing area of 1,215 square inches. All-up
weight is between 15 and 19 pounds. Two
.46-.60 glow, two-stroke engines or the
equivalent in electric power can run it.
For more information, please visit Rich’s
Web site.
In the early 1960s, the Marine Corps
needed a reconnaissance/light attack aircraft
that could be flown from unimproved fields.
In 1963, a triservice specification (Army,
Navy, Air Force) called LARA (Light Armed
Reconnaissance Aircraft) was issued. Eleven
proposals were submitted from varying
manufacturers, and North American
Rockwell’s NA-300 won the bid.
Although the aircraft was originally
envisioned as a small, simple, lightweight
aircraft with a 20-foot wingspan that could
operate on roadways and in jungle conditions,
it ended up having a 40-foot wingspan, 1,000-
pound rough-field landing gear, full
electronics, ejection seats, and an all-up
empty weight of approximately 7,000 pounds
that needed to operate from runways. This
was a long way from the “lightweight”
aircraft as proposed, but the new aircraft,
despite its size, had great potential.
Mission capabilities included observation,
forward air control, helicopter escort, armed
reconnaissance, gunfire spotting, utility, and
limited ground attack. However, the US Air
Force acquired the Bronco primarily as a
forward air control aircraft. It was also
useful as a low-level aerial photography
aircraft.
The Bronco also provided transportation
for aerial radiological reconnaissance,
tactical air observers, artillery and naval
gunfire spotting, and airborne controllers of
tactical air support operations.
The first Bronco used in combat arrived
in Vietnam in July 1968. The last Broncos
were decommissioned in 1995.
Approximately 300 were built.
The majority of RC Giant aircraft use
gasoline as the fuel for power. Most fuels
sold today are classified as E10, which is a
mixture of 10% ethanol and 90% gasoline.
Laws in states such as New York,
Connecticut, and California mandate its use,
and other states are quickly adopting the
practice.
In the near future, it may be difficult to
find regular gasoline at the pumps. You
may have to visit your nearby airfield to
purchase Avgas, which contains no ethanol.
An ethanol/gasoline mixture is not a
new phenomenon. In the early to mid-
1970s, during the first energy crisis, ethanol
was added to gasoline and marketed as
gasohol. Today ethanol is added to gasoline
to reduce harmful emissions and our
dependence on foreign oil; however, there
are pros and cons to ethanol use.
Ethanol is ethyl alcohol or grain alcohol,
made by fermenting any material that
contains starch or sugar. For many years, it
was used to make white lightning: a 190-
proof drink. In the US, corn is primarily
used to make ethanol. A bushel of corn can
yield 2.5 to 2.7 gallons. The addition of as
little as 10% ethanol to gasoline increases
its octane by 3 points, resulting in increased
performance.
Ethanol’s increased oxygen content
ensures that the gasoline burns more
completely, thus reducing tailpipe
emissions, especially harmful carbon
monoxide. However, a couple years after
ethanol’s introduction, small-engine repair
shops are reporting increasing instances of
fuel-related problems. MSNBC reported the
following:
“If you’ve been having trouble with
your small gasoline power equipment
lately, MSNBC reports that you’re not
alone: Small-engine mechanics nationwide
are seeing a spike in engine damage they
claim is attributable to the increasing use of
ethanol in gasoline. We’re not talking about
E85 here either; apparently, it’s the much
more common (and in some places
ubiquitous) E10 blend, which is 10%
ethanol and 90% gasoline, that technicians
are blaming for gummed-up carburetors,
internal rust and lubrication issues.
“Of course, ethanol trade groups are
claiming their extensive testing showed no
adverse effects from running E10 in small gas
engines. But the mechanics’ descriptions of
what they’re seeing, coupled with the known
properties of ethanol, make for a compelling
argument. Since ethanol combines readily
with water, gasoline containing ethanol easily
transports that suspended water into the
engine. Once inside, the water can gum up
carburetors and cause rust on key components,
leading to rapid wear and eventual
breakdown.
“On two-stroke engines, the potential for
damage is even more acute. Small two-strokes
carry their lubricating oil suspended in the
air/fuel mixture. Mechanics are reporting that
the presence of water in that mixture, carried
by ethanol, is causing the lubricating oil to
disperse before it reaches critical engine
components. Since an oil-starved engine
doesn’t last long, customers are reporting
mechanical failure after only a season or two
of use.
“Other small engine repair facilities have
reported similar issues. But the Renewable
Fuels Association, a trade group for ethanol
producers based in Washington, says there’s
no evidence that ethanol can damage small
engines. ‘Tests completed on lawnmowers,
chainsaws, weed trimmers and blower-vacs
with ethanol fuels showed no engine failures,
no unscheduled maintenance and good
performance,’ the association said.
“In addition, another individual who owns
a large lawn care company states that news
articles claiming ethanol related problems
goes against his own experience. For the last
two years, he has used only E10 in all his
small engines and hasn’t had the first problem
related to fuel.”
So what’s the truth and whom should
modelers believe? I suggest that we trust our
fellow modelers. Many of us know modelers
who tinker and excel in small-engine use. Ask
how their engines are performing using E10.
Ethanol does attract moisture and is a
solvent, but at 10% I have not seen all the
corrosive effects that have been reported.
However, our two-stroke fuel systems and
engines are fairly simple to operate and
maintain.
Each season you should replace the fuel
tubing in your fuel tank and the lines going to
the carburetor. Why? Because the fuel tubing
we use, whether Tygon or Aerotrend, hardens
over time. The fuel pickup line and clunk will
not operate properly when the fuel line
hardens.
In the accompanying photo, the upper fuel
stopper has a new piece of Tygon fuel line
attached. It is supple, and the weight of the
clunk makes the line droop the way you want
it to when it is inside your tank. This way, the
clunk will rest in the fuel regardless of the
attitude of your model in the air.
The lower fuel line in the picture is a
couple years old and has hardened to the point
that it stands straight out. This is okay if
you’re flying straight and level, but your
engine will starve for fuel while the aircraft is
inverted.
Another photo shows a typical Walbro
carburetor disassembled with the gaskets
removed. These gaskets can harden and cause
fuel-flow problems. The diaphragm gasket
uses crankcase pressure to pump fuel from the
tank to the engine. If the diaphragm has
hardened, the engine will not run properly.
These gaskets can be purchased at a local
lawn mower repair shop or online at your
favorite hobby store that specializes in gas
engines.
A photo shows a small screen that traps
particles that come from the fuel tank. It’s a
good idea to check and clean this screen from
time to time, to keep your engine running
smoothly.
The “Federal Study on Ethanol in Small
Engines” was released on December 3, 2008.
It’s 136 pages long and can be found online.
(See Sources.)
So ends this month’s column. As always,
comments, suggestions, and photos are
appreciated. MA
Sources:
Southeast R/C Engines, LLC
(904) 463-1098
www.southeastrcengines.com
Rich Uravitch
www.richuravitch.com
Federal Study on Ethanol in Small Engines
http://feerc.ornl.gov/publications/Int_blends_
Rpt_1.pdf
Edition: Model Aviation - 2009/03
Page Numbers: 102,103,104,106
Edition: Model Aviation - 2009/03
Page Numbers: 102,103,104,106
Also included in this column:
• Giant OV-10 Bronco
• Ethanol impacts
IT’S NO SECRET that our economy is in a
recession; most of the world is suffering from
the same economic woes. As we tighten our
fiscal belts, the first cutbacks usually involve
discretionary spending. Discretionary income
includes money spent on luxury items,
vacations, and nonessential goods and
services.
For many of our readers, this means
spending less on hobby-related items, but
don’t despair. If you look around, there are
some recession-busting deals to be found. If
you’re in need of a new gas engine for your
latest project, look at the offerings at
Southeast R/C Engines. The company’s line
of XYZ gas engines come complete with
ignition module, muffler, and mount, all for a
great price.
Southeast R/C Engines, located in
Jacksonville, Florida, is the importer and
distributor for the XYZ line of small twostroke,
gasoline-powered power plants. The
company had been searching for small twostroke
engines for use in the radio-control
aircraft. It ordered and tested many types
before discovering the XYZ.
These engines are manufactured to the
highest standards using billet aluminum and
CNC machining to form the crankcase. They
start easily, have very little vibration, and idle
at 2,100 rpm right out of the box.
After running the 50cc engine on the test
bench for more than 10 hours at 3,000 rpm, it
was disassembled to the last nut and found
that it was just starting to break in, and doing
it nicely. It looked great, bearings were fine,
and there were no misalignment marks or
loose bolts. The same procedure was repeated
for the 26cc engine with similar findings.
The 26-C and 50-A are short-stroke, bigbore,
two-stroke designs. Southeast R/C
Engines’ newest offering is an XYZ-50-HP
(high performance).
The 26cc model is compact, has a 45°
offset spark plug, has a Walbro WT-793
carburetor, and weighs 2 pounds, 8 ounces
including muffler and ignition module. This
engine will swing an APC 16 x 8 propeller at
7,600 rpm and is rated at 2.5 horsepower.
The XYZ 50-A has a displacement of 50cc
and is rated at 4.5 horsepower. The street
price for the 26-C is $209.95 and the 50-A is
$259.95. For more information about these
engines, please visit the Southeast R/C Web
site.
Rich Uravitch is a familiar name in the RC
industry. He has more than 40 years of RC
experience under his belt and is a frequent
contributor to many of the current modeling
publications. In addition to Rich’s stint in the
Air Force, his qualifications include editorial
director, editor-in-chief, author, model
designer, design consultant, Top Gun
competitor, and Top Gun craftsmanship
judge.
Rich currently enjoys designing models
that can use an electric power source, because
it offers tremendous potential to Scale
modelers. One of his latest is an International
Miniature Aircraft Association (IMAA)-legal,
81.5-inch-wingspan OV-10 Bronco.
The Bronco is 79.5 inches long and has a
wing area of 1,215 square inches. All-up
weight is between 15 and 19 pounds. Two
.46-.60 glow, two-stroke engines or the
equivalent in electric power can run it.
For more information, please visit Rich’s
Web site.
In the early 1960s, the Marine Corps
needed a reconnaissance/light attack aircraft
that could be flown from unimproved fields.
In 1963, a triservice specification (Army,
Navy, Air Force) called LARA (Light Armed
Reconnaissance Aircraft) was issued. Eleven
proposals were submitted from varying
manufacturers, and North American
Rockwell’s NA-300 won the bid.
Although the aircraft was originally
envisioned as a small, simple, lightweight
aircraft with a 20-foot wingspan that could
operate on roadways and in jungle conditions,
it ended up having a 40-foot wingspan, 1,000-
pound rough-field landing gear, full
electronics, ejection seats, and an all-up
empty weight of approximately 7,000 pounds
that needed to operate from runways. This
was a long way from the “lightweight”
aircraft as proposed, but the new aircraft,
despite its size, had great potential.
Mission capabilities included observation,
forward air control, helicopter escort, armed
reconnaissance, gunfire spotting, utility, and
limited ground attack. However, the US Air
Force acquired the Bronco primarily as a
forward air control aircraft. It was also
useful as a low-level aerial photography
aircraft.
The Bronco also provided transportation
for aerial radiological reconnaissance,
tactical air observers, artillery and naval
gunfire spotting, and airborne controllers of
tactical air support operations.
The first Bronco used in combat arrived
in Vietnam in July 1968. The last Broncos
were decommissioned in 1995.
Approximately 300 were built.
The majority of RC Giant aircraft use
gasoline as the fuel for power. Most fuels
sold today are classified as E10, which is a
mixture of 10% ethanol and 90% gasoline.
Laws in states such as New York,
Connecticut, and California mandate its use,
and other states are quickly adopting the
practice.
In the near future, it may be difficult to
find regular gasoline at the pumps. You
may have to visit your nearby airfield to
purchase Avgas, which contains no ethanol.
An ethanol/gasoline mixture is not a
new phenomenon. In the early to mid-
1970s, during the first energy crisis, ethanol
was added to gasoline and marketed as
gasohol. Today ethanol is added to gasoline
to reduce harmful emissions and our
dependence on foreign oil; however, there
are pros and cons to ethanol use.
Ethanol is ethyl alcohol or grain alcohol,
made by fermenting any material that
contains starch or sugar. For many years, it
was used to make white lightning: a 190-
proof drink. In the US, corn is primarily
used to make ethanol. A bushel of corn can
yield 2.5 to 2.7 gallons. The addition of as
little as 10% ethanol to gasoline increases
its octane by 3 points, resulting in increased
performance.
Ethanol’s increased oxygen content
ensures that the gasoline burns more
completely, thus reducing tailpipe
emissions, especially harmful carbon
monoxide. However, a couple years after
ethanol’s introduction, small-engine repair
shops are reporting increasing instances of
fuel-related problems. MSNBC reported the
following:
“If you’ve been having trouble with
your small gasoline power equipment
lately, MSNBC reports that you’re not
alone: Small-engine mechanics nationwide
are seeing a spike in engine damage they
claim is attributable to the increasing use of
ethanol in gasoline. We’re not talking about
E85 here either; apparently, it’s the much
more common (and in some places
ubiquitous) E10 blend, which is 10%
ethanol and 90% gasoline, that technicians
are blaming for gummed-up carburetors,
internal rust and lubrication issues.
“Of course, ethanol trade groups are
claiming their extensive testing showed no
adverse effects from running E10 in small gas
engines. But the mechanics’ descriptions of
what they’re seeing, coupled with the known
properties of ethanol, make for a compelling
argument. Since ethanol combines readily
with water, gasoline containing ethanol easily
transports that suspended water into the
engine. Once inside, the water can gum up
carburetors and cause rust on key components,
leading to rapid wear and eventual
breakdown.
“On two-stroke engines, the potential for
damage is even more acute. Small two-strokes
carry their lubricating oil suspended in the
air/fuel mixture. Mechanics are reporting that
the presence of water in that mixture, carried
by ethanol, is causing the lubricating oil to
disperse before it reaches critical engine
components. Since an oil-starved engine
doesn’t last long, customers are reporting
mechanical failure after only a season or two
of use.
“Other small engine repair facilities have
reported similar issues. But the Renewable
Fuels Association, a trade group for ethanol
producers based in Washington, says there’s
no evidence that ethanol can damage small
engines. ‘Tests completed on lawnmowers,
chainsaws, weed trimmers and blower-vacs
with ethanol fuels showed no engine failures,
no unscheduled maintenance and good
performance,’ the association said.
“In addition, another individual who owns
a large lawn care company states that news
articles claiming ethanol related problems
goes against his own experience. For the last
two years, he has used only E10 in all his
small engines and hasn’t had the first problem
related to fuel.”
So what’s the truth and whom should
modelers believe? I suggest that we trust our
fellow modelers. Many of us know modelers
who tinker and excel in small-engine use. Ask
how their engines are performing using E10.
Ethanol does attract moisture and is a
solvent, but at 10% I have not seen all the
corrosive effects that have been reported.
However, our two-stroke fuel systems and
engines are fairly simple to operate and
maintain.
Each season you should replace the fuel
tubing in your fuel tank and the lines going to
the carburetor. Why? Because the fuel tubing
we use, whether Tygon or Aerotrend, hardens
over time. The fuel pickup line and clunk will
not operate properly when the fuel line
hardens.
In the accompanying photo, the upper fuel
stopper has a new piece of Tygon fuel line
attached. It is supple, and the weight of the
clunk makes the line droop the way you want
it to when it is inside your tank. This way, the
clunk will rest in the fuel regardless of the
attitude of your model in the air.
The lower fuel line in the picture is a
couple years old and has hardened to the point
that it stands straight out. This is okay if
you’re flying straight and level, but your
engine will starve for fuel while the aircraft is
inverted.
Another photo shows a typical Walbro
carburetor disassembled with the gaskets
removed. These gaskets can harden and cause
fuel-flow problems. The diaphragm gasket
uses crankcase pressure to pump fuel from the
tank to the engine. If the diaphragm has
hardened, the engine will not run properly.
These gaskets can be purchased at a local
lawn mower repair shop or online at your
favorite hobby store that specializes in gas
engines.
A photo shows a small screen that traps
particles that come from the fuel tank. It’s a
good idea to check and clean this screen from
time to time, to keep your engine running
smoothly.
The “Federal Study on Ethanol in Small
Engines” was released on December 3, 2008.
It’s 136 pages long and can be found online.
(See Sources.)
So ends this month’s column. As always,
comments, suggestions, and photos are
appreciated. MA
Sources:
Southeast R/C Engines, LLC
(904) 463-1098
www.southeastrcengines.com
Rich Uravitch
www.richuravitch.com
Federal Study on Ethanol in Small Engines
http://feerc.ornl.gov/publications/Int_blends_
Rpt_1.pdf
Edition: Model Aviation - 2009/03
Page Numbers: 102,103,104,106
Also included in this column:
• Giant OV-10 Bronco
• Ethanol impacts
IT’S NO SECRET that our economy is in a
recession; most of the world is suffering from
the same economic woes. As we tighten our
fiscal belts, the first cutbacks usually involve
discretionary spending. Discretionary income
includes money spent on luxury items,
vacations, and nonessential goods and
services.
For many of our readers, this means
spending less on hobby-related items, but
don’t despair. If you look around, there are
some recession-busting deals to be found. If
you’re in need of a new gas engine for your
latest project, look at the offerings at
Southeast R/C Engines. The company’s line
of XYZ gas engines come complete with
ignition module, muffler, and mount, all for a
great price.
Southeast R/C Engines, located in
Jacksonville, Florida, is the importer and
distributor for the XYZ line of small twostroke,
gasoline-powered power plants. The
company had been searching for small twostroke
engines for use in the radio-control
aircraft. It ordered and tested many types
before discovering the XYZ.
These engines are manufactured to the
highest standards using billet aluminum and
CNC machining to form the crankcase. They
start easily, have very little vibration, and idle
at 2,100 rpm right out of the box.
After running the 50cc engine on the test
bench for more than 10 hours at 3,000 rpm, it
was disassembled to the last nut and found
that it was just starting to break in, and doing
it nicely. It looked great, bearings were fine,
and there were no misalignment marks or
loose bolts. The same procedure was repeated
for the 26cc engine with similar findings.
The 26-C and 50-A are short-stroke, bigbore,
two-stroke designs. Southeast R/C
Engines’ newest offering is an XYZ-50-HP
(high performance).
The 26cc model is compact, has a 45°
offset spark plug, has a Walbro WT-793
carburetor, and weighs 2 pounds, 8 ounces
including muffler and ignition module. This
engine will swing an APC 16 x 8 propeller at
7,600 rpm and is rated at 2.5 horsepower.
The XYZ 50-A has a displacement of 50cc
and is rated at 4.5 horsepower. The street
price for the 26-C is $209.95 and the 50-A is
$259.95. For more information about these
engines, please visit the Southeast R/C Web
site.
Rich Uravitch is a familiar name in the RC
industry. He has more than 40 years of RC
experience under his belt and is a frequent
contributor to many of the current modeling
publications. In addition to Rich’s stint in the
Air Force, his qualifications include editorial
director, editor-in-chief, author, model
designer, design consultant, Top Gun
competitor, and Top Gun craftsmanship
judge.
Rich currently enjoys designing models
that can use an electric power source, because
it offers tremendous potential to Scale
modelers. One of his latest is an International
Miniature Aircraft Association (IMAA)-legal,
81.5-inch-wingspan OV-10 Bronco.
The Bronco is 79.5 inches long and has a
wing area of 1,215 square inches. All-up
weight is between 15 and 19 pounds. Two
.46-.60 glow, two-stroke engines or the
equivalent in electric power can run it.
For more information, please visit Rich’s
Web site.
In the early 1960s, the Marine Corps
needed a reconnaissance/light attack aircraft
that could be flown from unimproved fields.
In 1963, a triservice specification (Army,
Navy, Air Force) called LARA (Light Armed
Reconnaissance Aircraft) was issued. Eleven
proposals were submitted from varying
manufacturers, and North American
Rockwell’s NA-300 won the bid.
Although the aircraft was originally
envisioned as a small, simple, lightweight
aircraft with a 20-foot wingspan that could
operate on roadways and in jungle conditions,
it ended up having a 40-foot wingspan, 1,000-
pound rough-field landing gear, full
electronics, ejection seats, and an all-up
empty weight of approximately 7,000 pounds
that needed to operate from runways. This
was a long way from the “lightweight”
aircraft as proposed, but the new aircraft,
despite its size, had great potential.
Mission capabilities included observation,
forward air control, helicopter escort, armed
reconnaissance, gunfire spotting, utility, and
limited ground attack. However, the US Air
Force acquired the Bronco primarily as a
forward air control aircraft. It was also
useful as a low-level aerial photography
aircraft.
The Bronco also provided transportation
for aerial radiological reconnaissance,
tactical air observers, artillery and naval
gunfire spotting, and airborne controllers of
tactical air support operations.
The first Bronco used in combat arrived
in Vietnam in July 1968. The last Broncos
were decommissioned in 1995.
Approximately 300 were built.
The majority of RC Giant aircraft use
gasoline as the fuel for power. Most fuels
sold today are classified as E10, which is a
mixture of 10% ethanol and 90% gasoline.
Laws in states such as New York,
Connecticut, and California mandate its use,
and other states are quickly adopting the
practice.
In the near future, it may be difficult to
find regular gasoline at the pumps. You
may have to visit your nearby airfield to
purchase Avgas, which contains no ethanol.
An ethanol/gasoline mixture is not a
new phenomenon. In the early to mid-
1970s, during the first energy crisis, ethanol
was added to gasoline and marketed as
gasohol. Today ethanol is added to gasoline
to reduce harmful emissions and our
dependence on foreign oil; however, there
are pros and cons to ethanol use.
Ethanol is ethyl alcohol or grain alcohol,
made by fermenting any material that
contains starch or sugar. For many years, it
was used to make white lightning: a 190-
proof drink. In the US, corn is primarily
used to make ethanol. A bushel of corn can
yield 2.5 to 2.7 gallons. The addition of as
little as 10% ethanol to gasoline increases
its octane by 3 points, resulting in increased
performance.
Ethanol’s increased oxygen content
ensures that the gasoline burns more
completely, thus reducing tailpipe
emissions, especially harmful carbon
monoxide. However, a couple years after
ethanol’s introduction, small-engine repair
shops are reporting increasing instances of
fuel-related problems. MSNBC reported the
following:
“If you’ve been having trouble with
your small gasoline power equipment
lately, MSNBC reports that you’re not
alone: Small-engine mechanics nationwide
are seeing a spike in engine damage they
claim is attributable to the increasing use of
ethanol in gasoline. We’re not talking about
E85 here either; apparently, it’s the much
more common (and in some places
ubiquitous) E10 blend, which is 10%
ethanol and 90% gasoline, that technicians
are blaming for gummed-up carburetors,
internal rust and lubrication issues.
“Of course, ethanol trade groups are
claiming their extensive testing showed no
adverse effects from running E10 in small gas
engines. But the mechanics’ descriptions of
what they’re seeing, coupled with the known
properties of ethanol, make for a compelling
argument. Since ethanol combines readily
with water, gasoline containing ethanol easily
transports that suspended water into the
engine. Once inside, the water can gum up
carburetors and cause rust on key components,
leading to rapid wear and eventual
breakdown.
“On two-stroke engines, the potential for
damage is even more acute. Small two-strokes
carry their lubricating oil suspended in the
air/fuel mixture. Mechanics are reporting that
the presence of water in that mixture, carried
by ethanol, is causing the lubricating oil to
disperse before it reaches critical engine
components. Since an oil-starved engine
doesn’t last long, customers are reporting
mechanical failure after only a season or two
of use.
“Other small engine repair facilities have
reported similar issues. But the Renewable
Fuels Association, a trade group for ethanol
producers based in Washington, says there’s
no evidence that ethanol can damage small
engines. ‘Tests completed on lawnmowers,
chainsaws, weed trimmers and blower-vacs
with ethanol fuels showed no engine failures,
no unscheduled maintenance and good
performance,’ the association said.
“In addition, another individual who owns
a large lawn care company states that news
articles claiming ethanol related problems
goes against his own experience. For the last
two years, he has used only E10 in all his
small engines and hasn’t had the first problem
related to fuel.”
So what’s the truth and whom should
modelers believe? I suggest that we trust our
fellow modelers. Many of us know modelers
who tinker and excel in small-engine use. Ask
how their engines are performing using E10.
Ethanol does attract moisture and is a
solvent, but at 10% I have not seen all the
corrosive effects that have been reported.
However, our two-stroke fuel systems and
engines are fairly simple to operate and
maintain.
Each season you should replace the fuel
tubing in your fuel tank and the lines going to
the carburetor. Why? Because the fuel tubing
we use, whether Tygon or Aerotrend, hardens
over time. The fuel pickup line and clunk will
not operate properly when the fuel line
hardens.
In the accompanying photo, the upper fuel
stopper has a new piece of Tygon fuel line
attached. It is supple, and the weight of the
clunk makes the line droop the way you want
it to when it is inside your tank. This way, the
clunk will rest in the fuel regardless of the
attitude of your model in the air.
The lower fuel line in the picture is a
couple years old and has hardened to the point
that it stands straight out. This is okay if
you’re flying straight and level, but your
engine will starve for fuel while the aircraft is
inverted.
Another photo shows a typical Walbro
carburetor disassembled with the gaskets
removed. These gaskets can harden and cause
fuel-flow problems. The diaphragm gasket
uses crankcase pressure to pump fuel from the
tank to the engine. If the diaphragm has
hardened, the engine will not run properly.
These gaskets can be purchased at a local
lawn mower repair shop or online at your
favorite hobby store that specializes in gas
engines.
A photo shows a small screen that traps
particles that come from the fuel tank. It’s a
good idea to check and clean this screen from
time to time, to keep your engine running
smoothly.
The “Federal Study on Ethanol in Small
Engines” was released on December 3, 2008.
It’s 136 pages long and can be found online.
(See Sources.)
So ends this month’s column. As always,
comments, suggestions, and photos are
appreciated. MA
Sources:
Southeast R/C Engines, LLC
(904) 463-1098
www.southeastrcengines.com
Rich Uravitch
www.richuravitch.com
Federal Study on Ethanol in Small Engines
http://feerc.ornl.gov/publications/Int_blends_
Rpt_1.pdf
Edition: Model Aviation - 2009/03
Page Numbers: 102,103,104,106
Also included in this column:
• Giant OV-10 Bronco
• Ethanol impacts
IT’S NO SECRET that our economy is in a
recession; most of the world is suffering from
the same economic woes. As we tighten our
fiscal belts, the first cutbacks usually involve
discretionary spending. Discretionary income
includes money spent on luxury items,
vacations, and nonessential goods and
services.
For many of our readers, this means
spending less on hobby-related items, but
don’t despair. If you look around, there are
some recession-busting deals to be found. If
you’re in need of a new gas engine for your
latest project, look at the offerings at
Southeast R/C Engines. The company’s line
of XYZ gas engines come complete with
ignition module, muffler, and mount, all for a
great price.
Southeast R/C Engines, located in
Jacksonville, Florida, is the importer and
distributor for the XYZ line of small twostroke,
gasoline-powered power plants. The
company had been searching for small twostroke
engines for use in the radio-control
aircraft. It ordered and tested many types
before discovering the XYZ.
These engines are manufactured to the
highest standards using billet aluminum and
CNC machining to form the crankcase. They
start easily, have very little vibration, and idle
at 2,100 rpm right out of the box.
After running the 50cc engine on the test
bench for more than 10 hours at 3,000 rpm, it
was disassembled to the last nut and found
that it was just starting to break in, and doing
it nicely. It looked great, bearings were fine,
and there were no misalignment marks or
loose bolts. The same procedure was repeated
for the 26cc engine with similar findings.
The 26-C and 50-A are short-stroke, bigbore,
two-stroke designs. Southeast R/C
Engines’ newest offering is an XYZ-50-HP
(high performance).
The 26cc model is compact, has a 45°
offset spark plug, has a Walbro WT-793
carburetor, and weighs 2 pounds, 8 ounces
including muffler and ignition module. This
engine will swing an APC 16 x 8 propeller at
7,600 rpm and is rated at 2.5 horsepower.
The XYZ 50-A has a displacement of 50cc
and is rated at 4.5 horsepower. The street
price for the 26-C is $209.95 and the 50-A is
$259.95. For more information about these
engines, please visit the Southeast R/C Web
site.
Rich Uravitch is a familiar name in the RC
industry. He has more than 40 years of RC
experience under his belt and is a frequent
contributor to many of the current modeling
publications. In addition to Rich’s stint in the
Air Force, his qualifications include editorial
director, editor-in-chief, author, model
designer, design consultant, Top Gun
competitor, and Top Gun craftsmanship
judge.
Rich currently enjoys designing models
that can use an electric power source, because
it offers tremendous potential to Scale
modelers. One of his latest is an International
Miniature Aircraft Association (IMAA)-legal,
81.5-inch-wingspan OV-10 Bronco.
The Bronco is 79.5 inches long and has a
wing area of 1,215 square inches. All-up
weight is between 15 and 19 pounds. Two
.46-.60 glow, two-stroke engines or the
equivalent in electric power can run it.
For more information, please visit Rich’s
Web site.
In the early 1960s, the Marine Corps
needed a reconnaissance/light attack aircraft
that could be flown from unimproved fields.
In 1963, a triservice specification (Army,
Navy, Air Force) called LARA (Light Armed
Reconnaissance Aircraft) was issued. Eleven
proposals were submitted from varying
manufacturers, and North American
Rockwell’s NA-300 won the bid.
Although the aircraft was originally
envisioned as a small, simple, lightweight
aircraft with a 20-foot wingspan that could
operate on roadways and in jungle conditions,
it ended up having a 40-foot wingspan, 1,000-
pound rough-field landing gear, full
electronics, ejection seats, and an all-up
empty weight of approximately 7,000 pounds
that needed to operate from runways. This
was a long way from the “lightweight”
aircraft as proposed, but the new aircraft,
despite its size, had great potential.
Mission capabilities included observation,
forward air control, helicopter escort, armed
reconnaissance, gunfire spotting, utility, and
limited ground attack. However, the US Air
Force acquired the Bronco primarily as a
forward air control aircraft. It was also
useful as a low-level aerial photography
aircraft.
The Bronco also provided transportation
for aerial radiological reconnaissance,
tactical air observers, artillery and naval
gunfire spotting, and airborne controllers of
tactical air support operations.
The first Bronco used in combat arrived
in Vietnam in July 1968. The last Broncos
were decommissioned in 1995.
Approximately 300 were built.
The majority of RC Giant aircraft use
gasoline as the fuel for power. Most fuels
sold today are classified as E10, which is a
mixture of 10% ethanol and 90% gasoline.
Laws in states such as New York,
Connecticut, and California mandate its use,
and other states are quickly adopting the
practice.
In the near future, it may be difficult to
find regular gasoline at the pumps. You
may have to visit your nearby airfield to
purchase Avgas, which contains no ethanol.
An ethanol/gasoline mixture is not a
new phenomenon. In the early to mid-
1970s, during the first energy crisis, ethanol
was added to gasoline and marketed as
gasohol. Today ethanol is added to gasoline
to reduce harmful emissions and our
dependence on foreign oil; however, there
are pros and cons to ethanol use.
Ethanol is ethyl alcohol or grain alcohol,
made by fermenting any material that
contains starch or sugar. For many years, it
was used to make white lightning: a 190-
proof drink. In the US, corn is primarily
used to make ethanol. A bushel of corn can
yield 2.5 to 2.7 gallons. The addition of as
little as 10% ethanol to gasoline increases
its octane by 3 points, resulting in increased
performance.
Ethanol’s increased oxygen content
ensures that the gasoline burns more
completely, thus reducing tailpipe
emissions, especially harmful carbon
monoxide. However, a couple years after
ethanol’s introduction, small-engine repair
shops are reporting increasing instances of
fuel-related problems. MSNBC reported the
following:
“If you’ve been having trouble with
your small gasoline power equipment
lately, MSNBC reports that you’re not
alone: Small-engine mechanics nationwide
are seeing a spike in engine damage they
claim is attributable to the increasing use of
ethanol in gasoline. We’re not talking about
E85 here either; apparently, it’s the much
more common (and in some places
ubiquitous) E10 blend, which is 10%
ethanol and 90% gasoline, that technicians
are blaming for gummed-up carburetors,
internal rust and lubrication issues.
“Of course, ethanol trade groups are
claiming their extensive testing showed no
adverse effects from running E10 in small gas
engines. But the mechanics’ descriptions of
what they’re seeing, coupled with the known
properties of ethanol, make for a compelling
argument. Since ethanol combines readily
with water, gasoline containing ethanol easily
transports that suspended water into the
engine. Once inside, the water can gum up
carburetors and cause rust on key components,
leading to rapid wear and eventual
breakdown.
“On two-stroke engines, the potential for
damage is even more acute. Small two-strokes
carry their lubricating oil suspended in the
air/fuel mixture. Mechanics are reporting that
the presence of water in that mixture, carried
by ethanol, is causing the lubricating oil to
disperse before it reaches critical engine
components. Since an oil-starved engine
doesn’t last long, customers are reporting
mechanical failure after only a season or two
of use.
“Other small engine repair facilities have
reported similar issues. But the Renewable
Fuels Association, a trade group for ethanol
producers based in Washington, says there’s
no evidence that ethanol can damage small
engines. ‘Tests completed on lawnmowers,
chainsaws, weed trimmers and blower-vacs
with ethanol fuels showed no engine failures,
no unscheduled maintenance and good
performance,’ the association said.
“In addition, another individual who owns
a large lawn care company states that news
articles claiming ethanol related problems
goes against his own experience. For the last
two years, he has used only E10 in all his
small engines and hasn’t had the first problem
related to fuel.”
So what’s the truth and whom should
modelers believe? I suggest that we trust our
fellow modelers. Many of us know modelers
who tinker and excel in small-engine use. Ask
how their engines are performing using E10.
Ethanol does attract moisture and is a
solvent, but at 10% I have not seen all the
corrosive effects that have been reported.
However, our two-stroke fuel systems and
engines are fairly simple to operate and
maintain.
Each season you should replace the fuel
tubing in your fuel tank and the lines going to
the carburetor. Why? Because the fuel tubing
we use, whether Tygon or Aerotrend, hardens
over time. The fuel pickup line and clunk will
not operate properly when the fuel line
hardens.
In the accompanying photo, the upper fuel
stopper has a new piece of Tygon fuel line
attached. It is supple, and the weight of the
clunk makes the line droop the way you want
it to when it is inside your tank. This way, the
clunk will rest in the fuel regardless of the
attitude of your model in the air.
The lower fuel line in the picture is a
couple years old and has hardened to the point
that it stands straight out. This is okay if
you’re flying straight and level, but your
engine will starve for fuel while the aircraft is
inverted.
Another photo shows a typical Walbro
carburetor disassembled with the gaskets
removed. These gaskets can harden and cause
fuel-flow problems. The diaphragm gasket
uses crankcase pressure to pump fuel from the
tank to the engine. If the diaphragm has
hardened, the engine will not run properly.
These gaskets can be purchased at a local
lawn mower repair shop or online at your
favorite hobby store that specializes in gas
engines.
A photo shows a small screen that traps
particles that come from the fuel tank. It’s a
good idea to check and clean this screen from
time to time, to keep your engine running
smoothly.
The “Federal Study on Ethanol in Small
Engines” was released on December 3, 2008.
It’s 136 pages long and can be found online.
(See Sources.)
So ends this month’s column. As always,
comments, suggestions, and photos are
appreciated. MA
Sources:
Southeast R/C Engines, LLC
(904) 463-1098
www.southeastrcengines.com
Rich Uravitch
www.richuravitch.com
Federal Study on Ethanol in Small Engines
http://feerc.ornl.gov/publications/Int_blends_
Rpt_1.pdf
