Subaru water level

[StanFoster]

The first 30 hours of flying my SparrowHawk...I was trying to fix a problem that did not exist. I carefully got the air out of my cooling system and kept filling the water up to the cap...then adding a pint in my overflow. Not counting the time my thermostat stuck....I kept having water spurt out the top....kind of like a whales blow hole. It was annoying keeping my tail clean.

I was fearing I had a blown head gasket....and did a pressure test. I left it under 20 pounds of pressure for 3 hours and not so much as a needle movement.

I took the spark plugs out and looked for water in the cylinders....and even swabbed each bore and tasting only oil.

After that...I added an overflow tube and ran it from the overflow bottle down to my left landing gear. I can monitor it in flight and any water going out only hits my left tire.

After my 47 hours of flying now....I have found that my water level is happy just a little down from the cap. If I fill it to the cap.....it will blow out.

I have flown now for 20 some hours without a drop coming out and my problem wasnt there in the first place....except my not knowing what water level my system likes.

The first picture shows the overflow bottle with the clear hose I ran to keep my tail/engine clean. The second shows the outlet at my left tire.

Stan

[Timchick]

Stan,
You need to write a book with all your tips and tricks in it. Does the sparrowhawk company website have an area for builders to share their tips?

[Canadian Rhino]

Hi Stan. What do you think is going on there with that? When did it typically do the whale spew thing? Did you have to get up to some particular altitude or work it hard on a warm or hot day?
I have had mine running for good periods of time now while tied to a boulder and have not seen any of this happening.
You have me wondering if I should drain the expansion tank before first flight to save a tail and undergarmet washing experience!:eek:

[KenSandyEggo]

Stan, what percentage of the overflow-tank does the 1 pint use? Shouldn't be more than half from my experience, or I'd get the whale-job too.

[StanFoster]

Ken: I would guess that my overflow holds 2 pints. Not an accurate answer....just a guess. Whatever though....if I put ANY water in there it will spit it out. After a few flights it has its level its happy at.


My radiator looks much larger than other 2.5 Subarus have such as Mark Knights Air Command I just posted. Plus I am running a heater circuit as well.


I had a local guy that is an engine expert tell me that each engine/radiator combination has its own level its happy at.

Mine happens to be a few inches lower than the filler cap when cold.

I had it running hard last Monday in 92 degrees humid air with Jeff aboard. I had the rpms up for an hour and it didnt shed a drop. Had I put any in the reservoir it would have ejected out my drain line.

Anyway.....no problem .:D


Stan

[Caribean_gyro]

stan question the trim spring that I beleived are 2 in one. Is this an after maket of came fromSH guys. I all looking in to improving my actual triming set up

chuckP

[StanFoster]

Chuck: The electric trim came from "Im Flyin" out of Arizona. I am very pleased with it.



Stan

[Harry_S.]

Stan;

I had that same *blow out* with my 2.2 Sub when I first started flying it. I found that I had too much coolant in the surge tank. When the engine gets to operating temp. coolant flows to the tank, right?!

So, then and now, I don't have any extra fluid in the surge tank. After a flying session, the clear line from the rad cap to the tank is full of coolant. How much is in the tank...I don't know; never took the tank plug out to check how much was in there.

Whenever I go for a fly, in my preflight, the clear line is always empty and when I remove the rad cap to check the coolant...it's always right up to the top.


Cheers :)

[Gary_in_Orygun]

My 2.2 Subaru has never had any problems with the clear line to the overflow tank showing green. I like to see the fluid in that line and only once or twice do I remember any sticky green fluid up under my blades.

[Steve Osborne]

Stan, I had the same problem on my 2.2 last year at 580 hrs. Did all the test you described, even changed the head gaskets. At full power looking over my right shoulder I could see small bubbles in the clear tube running to the expansion tank. It would only would do this at full power. After landing I would have antifreeze on the mast and prop. Ended up installing a new water pump and have not had a problem since. I keep the clear tube level filled to about an 1/8" from the top engine cold. In the fall or winter when the outside temp drops you should notice the level in the tube dropping also. Keeping the clear tube level at least 3/4 full should prevent any air from entering the system as it expands and contracts.

[Rehan K.Janjua]

This is the Expansion Tank.

Only for the expanded coolant when the engine warms up and some more expansion
Which is sucked back in to the engine as it cools and contracts.

Usually the Ex tank is 1/2 to 3/4 full when cold, also the fully expanded coolant should fit in the tank.

Hope I m making sense or may be not, should wait for a wiser advice or at least a well explained whale job.

Regards
Rehan