| Rotax 582 engine modifications on CHINOOK + 2 |
The Rotax 582 engine, gearbox, and prop were purchased used for use on
my Chinook. The engine is a "gray head" model and had about 650 hours
of use when I bought it.
I knew the previous owner had taken very good care of this engine, and
never had a problem with it other than the oil injection would not pump the
correct mixture to the engine.
He purchased a new pump, new lines, new filters, etc. The injection system
was running at 120:1. Blocking the pump lever full on would only give 70:1
and he and I both carefully checked oil consumption over time, but could get
no better results. We could never solve this problem, and I have since heard
of others that also only use oil at 120:1. Nobody ever checks the oil
consumption, but they should.
The oil injection system was removed and mixing at 50:1 has been how the
engine has been run since. At about 650 hours, the previous owner thought
he would give a Hirth a try, and sold his old gray head engine, gearbox, and
prop to me.
I took the engine apart to be sure it was not damaged and was clean and
assembled correctly before installing it on my Chinook. I now have added
another 550 hours on this engine, and continue to mix at 50:1
Total hours on the engine is now 1200
One modification I made was to increase oil to the crankshaft rear main
bearings. The photos show how this was done with a Dremel type high
speed grinder and carbide burr.
Oil that flows down the hole to the rear bearing, ( or up in my case )
can be restricted by the rubber crankshaft seal. This seal has distance "feet"
that help position it. These feet can really restrict this hole , and I never hear
of re-builders talking about this. To help me position the seal correctly I
place a paint dot on the rear seal to line up with a paint mark where the hole
is. I also modified the hole so oil can blow through to the rear main bearing
more easily.
My 1995 Rotax gray head engine has never had any new parts added other
than gaskets & snap rings. It still has original pistons, rings, seals. I do
decarbon it every 300 hours or so, but this is an easy one day job. Kerosene
and #240 paper to clean the heads. Carburetor soak cleaner for pistons and
rings. Some use of a dental pick is helpful.
I always put the same piston in the same cylinder and have them marked. I
always put the same rings, with the same face up.
These parts are worn together and you can't get a better fit.
Any ring sticking starts opposite the exhaust ports at the ring gap. Wait too
long and you can't get the rings out of the pistons, then you are looking at
new pistons, honing, boring, etc.
I use Pennzoil Air Cooled.
my Chinook. The engine is a "gray head" model and had about 650 hours
of use when I bought it.
I knew the previous owner had taken very good care of this engine, and
never had a problem with it other than the oil injection would not pump the
correct mixture to the engine.
He purchased a new pump, new lines, new filters, etc. The injection system
was running at 120:1. Blocking the pump lever full on would only give 70:1
and he and I both carefully checked oil consumption over time, but could get
no better results. We could never solve this problem, and I have since heard
of others that also only use oil at 120:1. Nobody ever checks the oil
consumption, but they should.
The oil injection system was removed and mixing at 50:1 has been how the
engine has been run since. At about 650 hours, the previous owner thought
he would give a Hirth a try, and sold his old gray head engine, gearbox, and
prop to me.
I took the engine apart to be sure it was not damaged and was clean and
assembled correctly before installing it on my Chinook. I now have added
another 550 hours on this engine, and continue to mix at 50:1
Total hours on the engine is now 1200
One modification I made was to increase oil to the crankshaft rear main
bearings. The photos show how this was done with a Dremel type high
speed grinder and carbide burr.
Oil that flows down the hole to the rear bearing, ( or up in my case )
can be restricted by the rubber crankshaft seal. This seal has distance "feet"
that help position it. These feet can really restrict this hole , and I never hear
of re-builders talking about this. To help me position the seal correctly I
place a paint dot on the rear seal to line up with a paint mark where the hole
is. I also modified the hole so oil can blow through to the rear main bearing
more easily.
My 1995 Rotax gray head engine has never had any new parts added other
than gaskets & snap rings. It still has original pistons, rings, seals. I do
decarbon it every 300 hours or so, but this is an easy one day job. Kerosene
and #240 paper to clean the heads. Carburetor soak cleaner for pistons and
rings. Some use of a dental pick is helpful.
I always put the same piston in the same cylinder and have them marked. I
always put the same rings, with the same face up.
These parts are worn together and you can't get a better fit.
Any ring sticking starts opposite the exhaust ports at the ring gap. Wait too
long and you can't get the rings out of the pistons, then you are looking at
new pistons, honing, boring, etc.
I use Pennzoil Air Cooled.
One of modifications I made was to remove the set-screw that plugs the
drain hole from the water-pump seal. When the cases are split, you can
see the hole that drains into a existing slot that is milled between the
case halves.
Heating the screw, allowed me to remove it.
I am told that Rotax plugged this hole because owners would
complain if they saw any antifreeze leaking from joint between the
case halves.
With the hole plugged, any coolant that gets past the seal has no place to
go, but into the rotary valve oil. This is a common problem with the older
582 gray head engine that uses just a lip seal for the water-pump
To also fight this common problem with older gray head engines, I run my
cooling system without any pressure in the system. This removes pressure
from the lip seal on the water-pump, and I figure increases safety as I can
never have a cooling system "blow out" such as a blown hose or seal. I
run a 50/50 mix of coolant. Coolant raises the boiling point of water, and I
have no pressure cap. It works like a tea-kettle.
At the altitude I fly at, boiling is no problem. I have never seen any coolant
leaking from the slot shown here. I have never had any sort of overheating
problem, and it uses no coolant.
drain hole from the water-pump seal. When the cases are split, you can
see the hole that drains into a existing slot that is milled between the
case halves.
Heating the screw, allowed me to remove it.
I am told that Rotax plugged this hole because owners would
complain if they saw any antifreeze leaking from joint between the
case halves.
With the hole plugged, any coolant that gets past the seal has no place to
go, but into the rotary valve oil. This is a common problem with the older
582 gray head engine that uses just a lip seal for the water-pump
To also fight this common problem with older gray head engines, I run my
cooling system without any pressure in the system. This removes pressure
from the lip seal on the water-pump, and I figure increases safety as I can
never have a cooling system "blow out" such as a blown hose or seal. I
run a 50/50 mix of coolant. Coolant raises the boiling point of water, and I
have no pressure cap. It works like a tea-kettle.
At the altitude I fly at, boiling is no problem. I have never seen any coolant
leaking from the slot shown here. I have never had any sort of overheating
problem, and it uses no coolant.
My Rotax 582 now has 1200 hours on the original pistons and rings and crank.
Maximum revs are loaded to 6250 RPM, however, at 95 mph top speed revs are at
7000 RPM due to prop unloading.
When storing or parking the plane for more that a week, I always position the crankshaft
so both transfer ports are closed to prevent oil fouling the plugs. The crankshaft is
positioned by means of a paint mark on the rubber coupling visible through the hole in the
sides of the gearbox
In the photo at left you can see my over-temp switch in the cylinder head. This switch
was added to one of two holes I drilled and tapped into the cylinder head. The other hole
has a brass plug. ( Maybe a heater someday? )
The over-temp switch is a radiator fan switch from a 1987 Chrysler Lebaron, and it will
light a warning lamp on both panels if temp gets to 190 degrees. It has never lit.
Maximum revs are loaded to 6250 RPM, however, at 95 mph top speed revs are at
7000 RPM due to prop unloading.
When storing or parking the plane for more that a week, I always position the crankshaft
so both transfer ports are closed to prevent oil fouling the plugs. The crankshaft is
positioned by means of a paint mark on the rubber coupling visible through the hole in the
sides of the gearbox
In the photo at left you can see my over-temp switch in the cylinder head. This switch
was added to one of two holes I drilled and tapped into the cylinder head. The other hole
has a brass plug. ( Maybe a heater someday? )
The over-temp switch is a radiator fan switch from a 1987 Chrysler Lebaron, and it will
light a warning lamp on both panels if temp gets to 190 degrees. It has never lit.
I used a heater core from a school bus for a radiator. It has 5 rows of tubes. This early
photo shows white hoses, but I had trouble keeping the clamps tight, so now I use black
truck heater hose. The radiator is mounted to saddle clamps fitted to the gusset tube, and
has never given a problem. It stays on the plane when engine is removed.
A thermostat is used to keep temperature at a steady 160 degrees. Two 1/8 inch holes
were drilled in this thermostat to allow for filling the system, bleeding air, and keeping the
coolant around the thermostat at a more even temperature and prevent gulping. There is
also an air bleed hose mounted in the existing hole in the water-pump housing that returns
some air and coolant back to my recovery tank.
This photo shows the exhaust system and brackets I made to fit the old "right side up"
Quicksilver exhaust system.
photo shows white hoses, but I had trouble keeping the clamps tight, so now I use black
truck heater hose. The radiator is mounted to saddle clamps fitted to the gusset tube, and
has never given a problem. It stays on the plane when engine is removed.
A thermostat is used to keep temperature at a steady 160 degrees. Two 1/8 inch holes
were drilled in this thermostat to allow for filling the system, bleeding air, and keeping the
coolant around the thermostat at a more even temperature and prevent gulping. There is
also an air bleed hose mounted in the existing hole in the water-pump housing that returns
some air and coolant back to my recovery tank.
This photo shows the exhaust system and brackets I made to fit the old "right side up"
Quicksilver exhaust system.
At 1200 hours, this is how it looks.
Removal of piston rings
Soaking helps remove carbon.
Don't forget the underside of piston.
Don't forget the underside of piston.
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Different oils do make a difference as shown below. Some oils will cause you to
decarbon much more frequently. Some oils combine with lead in gasoline to give much
more carbon. Use unleaded fuel with no additives when you can get it.
decarbon much more frequently. Some oils combine with lead in gasoline to give much
more carbon. Use unleaded fuel with no additives when you can get it.
| If you have had trouble with rapid age cracking of your carburetor socket boots, CLICK HERE. JBM Industries, Kent, Ohio USA |