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Overheat on grey top 582 Avid C Type speed wing


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Posted

I'm thinking of buying this avid speed wing I think it's a C type but I'm told that it over heats with someone in the passenger seat it's only got 15 hour on the engine silver/grey top 582. It all looks fairly standard so;

What are the best ways to cool an engine with this type of installation?

Cheers

Alan von Stark

16751_7_P1000994.JPG

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Posted

Belly radiator.  Was the only way I could keep mine cool till I switched to the MK IV cowling and the twin rads in the nose with good baffling.

:BC:

 

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Posted

Thanks AKflyer I'm beginning to think along those lines myself.

I'm wondering if a small additional belly radiator might help and what what would be the problems involved with doing that?

There is a kind of belly radiator which is a copper tube with some ally fins stuck to it which all looks a bit questionable and the air intake hole looks very small to me especially when the carbs are sucking from the same source. The radiator just looks too small and the space behind it seems to be way to close to the firewall for the hot air that's passed through the radiator to exit efficiently .

I'm considering cleaning up the radiator air exit space by adding a few curves and maybe cutting an air inlet slit in the side of the cowling to better direct the air into the radiator.

There must have been a few guys who have been there before done that and got the tee shirt and if they have been able to make it work without changing to the MKIV cowlings and radiators I'd like to try that first.

It makes me wonder how such a set up was passed in the first place on what to me seems to be and incredibly well designed and aircraft.

But hey I've made a few boo boos and mistakes as well in my time ;)

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00034.MTS(AVCHD)_20180709_140530.979.jpg

00034.MTS(AVCHD)_20180709_140704.329.jpg

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Posted

I don't think that piece of piece of fin tube radiation will do very much.  It's used in hot water house heating systems.  But then I've been wrong before.  The Kitfox belly radiator will cool the 100 HP 912 engines by itself.  JImChuk

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Posted (edited)

I just upgraded to Rotax 670 and added a belly radiator. I used an older kitfox one that Edmo sent me, they also sell them on ebay. I ran two U-bolts thru the floor that circled the two diagonal steel members that go from the center of the pedal area out and back to the outer frame. You can see one of them peeking out in the photo. I used a 1.5" x 3" aluminum box, as a mount, cut away to lighten it but also to get access to the bolts. The hose is 1' ID high temp silicone form Amazon, really flexible. It needs to be 2" lower, doing that this week.

IMG_0650.jpg

Edited by nlappos
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Posted

Thanks Nlappos that looks much nicer than whats slung behind the Type C speed wing

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Posted (edited)

One benefit of the bellyrad is the aerodynamic shielding of those draggy round landing gear legs just behind, and tucked up against the belly.  I think that shielding helps reduce the penalty for just sticking that rad out in the stream, uncowled.  Of course, nothing says that cowling the rad will automatically reduce drag - that would require flight test data and careful aero design based on same, with some design iteration.

Another thought for improving cooling would be some kind of extended gill flap to help suck air thru the radiator.   That option, however, is inconsistent with the current bellyrad, as the rad will kill the momentum in that near-wall flow, so deflecting it away to create suction over the current in-cowl radiator's air exit would likely be futile.  Here is a great opportunity for a variable cowl flap, which could be closed down in  cold cruise conditions to reduce drag!

Edited by Turbo

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Posted

Turbo, you got real close to the problem according to our master designer ( D-W), when he was helping me build my cowl. “Remember you need 20 to 30 percent more air exit area than intake area due to the heat expansion of the air itself” also a nice 1/12” flair at the bottom of the cowl so the slipstream will suck the hot air out otherwise it tends to dam-up  and not cool properly. Hope this information might help in some cases. BTW Dean is not working in his shop anymore, got all his tools for sale, keeps pretty close to the oxygen generator, but I’ m sure he would enjoy a phone call especially those who know him.  Probably midday.

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Posted

Sad to hear Dean is sidelined, I'm sure it must be frustrating for such a prolific tinker/builder. Achieving even a small fraction of your worldly visions and immortality thru thankful recognition of your contributions is a fitting legacy for any fine man. Hat tip and Blue Skies to our Hero.

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Posted

Logtrucker,

Let Dean know we are all thinking about him and wish him the best!  Sad to hear that he is not doing so well. 

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Posted

all that stuff to cool inside drove me crazy. i made choice to save lot of work and weight by going on belly, then i can keep free of holes the cowling ; more aero benefits i think, specially with C cowling even if belly add some drag

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Posted (edited)

Well I bought the C type and have had a few adventures in her which I will post later on.

The main thing is that it has not overheated that bit of copper pipe with fins seems to work fine and I flown it when it's been 23C to 25C outside which is a good summer for Blighty (UK)

Nano Landing 02.jpg

Edited by alan von Stark
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