Water over flow bottle nessasary on 582

[Koevoet]

Question : viewtopic.php?f=3&t=9127

Picture - 016 ( to the seller - no critisism intended - just curious)

Is'nt there suppose to be a over flow water bottle (for the see through pipe coming out of the small radiator cap bottle).
See the pipe ends in the bottom out.

Just curious - does it work that way - thought there must be a over flow bottle attached?

Not a mechanical - thats why I ask - pro and cons on a long nav?

[John Young]

Hi Koevoet,

View of expansion tank highlighted.

Regards
John ZU-sEXY

[Mogas]

Rotax recommends the use of an overflow bottle in addition to the expansion tank.
The 3 reasons for the overflow bottle are - Catch the excess coolant released out of the expansion tank breather when the engine gets hotter than normal.
- Allow this captured coolant to be sucked back into the system when it cools down (the pipe end must be submerged).
- Probably most important of all, you can monitor your coolant level by simply looking at the level in the overflow bottle.
If the overflow bottle is not fitted it simply means coolant top ups more often. This can be a pain 'cause you should keep the anti freeze/water ratio the same.
Hope this helps Koevoet

[Koevoet]

Thax guys

[BOATCH]

I also have a problem when it is a hot day the temp gauge goes up to 80 -82 deg\c and then when i land and taxi back to the hanger there is some water coming out of the res bottel. I have replaced the radiater cap but to no avail. I have two radiaters on eatch side of the engine and one big radiater behind the motor.There is no pressure bottle cause the pressure cap is on the radiater.Can it be done to fit another press bottle.

[Mogas]

How big is the overflow bottle Boatch? Maybe its just too small.

[Z-MRP]

Hi Boatch, I notice u said u have 3 radiators on your 582 and u see the temp going up on a hot day. Your engine temp is controlled by the thermostat which has a preset open and close temperature setting. I am running a 618 just with the 2 small radiators mounted on the sides of the cylinder head and have a steady temp. Maybe check your heat range on the thermostat housing to see wat you have, a slight increase of temp on a hot day can be normal as the radiators are subject to ambient tempure effects ie less efficent. Small point on the over flow bottle the pipe must be all the way to the bottom so make sure you cut the end of the pipe off at an angle as when the system cools and recovers coolant from the bottle the pipe doent suck its self to the bottom of the bottle there by not refilling the system automaticlly and if u only check the overflow bottle for water level there is a risk you can be short of coolant in the motor. I always check the radiator is full before each flight no mater what the overflow bottle shows.

[BOATCH]

Mogas you and z-mrp have both got a point there that i have to check cause the bottle is 3cm+10cm and the point of the pipe is not down to the bottom so thanks i will have to check up on that

[Mogas]

Interesting discussion!
I personally don't like opening the radiator cap to check the coolant level at every pre-flight and only do this when I have serviced the cooling system. I start it up, get it to operating temperature then shut it down and then check it for leaks before I fly it.
The radiator cap not only keeps the coolant in the system but also provides a pressure seal. That seal must be intact for the system to work properly.
Thats why provided I know there are no leaks I am happy to pre-flight it with a look at the level in the overflow bottle.
Good point about the pipe end MRP.

[John Young]

The radiator cap not only keeps the coolant in the system but also provides a pressure seal

which can at 1.0 bar effectively raise the boiling point of the liquid by as much as 15°.

Regards
John ZU-sEXY

[Sukkelaar]

Rotax states that coolant temp should never, I repeat, never exeed 80 degrees C on a 582(Blue Top)
and not colder than 70 degrees C

Sukkelaar

[John Young]

Rotax states that coolant temp should never, I repeat, never exceed 80 degrees C on a 582 (Blue Top)
and not colder than 70 degrees C

which is why you won't find 1.0 bar caps on 582's.

By the way Sukkelaar, the advocated temps for 582 Blue Tops is 60º C (minimum) to 80º C (maximum). 70º C is considered optimum.

Interesting though, the higher you go, the lower the boiling point. At 25 000' AMSL, water would boil at 45º C without a pressurised radiator cap.

So Sukkelaar, at what temperature would water boil at 10 000' AMSL without a pressurised cap?

Regards
John ZU-sEXY

[ZU-CDW - Shark]

Hi Boatch,
I am referring to what Z-MRP informed you about as the High Execution radiator sold by Aviation Engines. 2 small radiator units on either side of the cylinder head and preferably mounted higher than the exhaust port when mounted on a trike as your passenger mostly blocks some of the airflow. When mounted in this position you only fit the overflow Rotax bottle which is a very over priced piece of plastic, but it is the correct size and the overflow pipe from the radiator fits at the bottom of the overflow bottle as required and explained before hand. I also have a 618 and with a passenger in the back it rarely goes beyond 70 oC.
The expansion tank is fitted when the radiators are installed below the motor e.g. the Raptor.
Regards

[Sukkelaar]

I do know that at the reef water boils @ about 97 degrees because of height above sea level. But this is immaterial as your radiator is pressurised and therefore boiling point would be way above 100 degrees. Thats why pressure cookers cook food so fast, the water say reaches 130 degrees instead of 100 degrees. Sorry about the 70 degrees minimum you are correct it is 60 degrees. This means that your cooling system should be A1 because you only have 20 degrees variance, which is very small, as to other makes and models.