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cooling issues

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Posted

Yesterday we went out and the temps were in the low 70's and I had issues with my cooling system.  I have the rotax dual radiators in the cowl and if I pushed harder than about 5600 the temps went to 185- 195.  I did a very shallow 40 mile climb out so I could get high enough to cross the open water.  At 5,000' the OAT was about 48 degrees and then she dropped down to 160 and ran cool even at 6100 RPM.  I started off with 50/50 mix on the coolant, but then tried it at about 30/70 coolant/water (distilled).  The temps came down a tad but not much.

Do any of you guys with in cowl radiators have a cooling issue?  I made baffles for the radiator so all air entering the cowling is forced through them.  This helped me in climbout as I can climb at a slower speed and still cool, but I am thinking it may be an issue of not enough exit air?  My feet get PLENTY of heat through the firewall if I run over about 5600 RPM.  I have insulation on the inside of the firewall but it still gets good and warm.  I am thinking of going to a belly mounts radiator, but I see plenty of planes flying around with the incowl rads.

Any thoughts?

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Posted

Well I cut out about a 2" strip from the bottom of the cowl and it did absolutely no good.  Thanks to Jackak I installed a belly mount radiator and all cooling issues went away.  I can fly as slow as I want, climb as hard as I want and never go above 160 so I am now "riding" the thermostat just as it should be.  Sure wish I would have done this before I butchered the cowling :lol:  Ohwell, live and learn, and a day in the shop with glass work and paint and no one will ever know!

:beerchug:

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Posted

Glad to see that the radiator worked for you Leni.  Any pictures of the install?

Jack

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Posted

Hey Jack,

I will get some next time home.  As it was, I got home, ran out to the airport, loaded her up, back to the house, worked on it til a little after midnight, then back in the garage at 4 am.  Made it back out to the airport for test flights at 6:45 am.  I did not take any pics along the way :lol:

Thanks again for the radiator!

:beerchug:

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Posted

Sounds like a nice relaxing day.... Good thing you had a job to go to so you can get some rest.

Jack

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Posted

well crap, I forgot to get pics when I was home.  I will get some when I get back in.  I need to work a different schedule.  2 weeks on 4 weeks off would be good for everything but the pocket book!

How close are you getting on your plane?  gotta be close to paint by now huh?  She will be a work of art when you get it in the air.

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Posted

Can someone show me some pics of a belly mount radiator that works, I have the big square rotax on an A model do I need to order the thin wide one from Kitfox or is there another good way of doing it?

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Posted

Can someone show me some pics of a belly mount radiator that works, I have the big square rotax on an A model do I need to order the thin wide one from Kitfox or is there another good way of doing it?

I put mine on using teflon 1.5" stand offs. Just held it up to the bottom of the plane, marked the holes and drilled trough the floor boards. Best thing I ever did in terms of cooling. I never see temps over 165 now and in the winter I have to run aluminum tape over about 1/2 the radiator to get temps over 140. If you zoom in on the pic, you can see the stand offs to get the radiator a little lower in the slip stream.

post-2-12730042345482_thumb.jpg

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Posted

I put mine on using teflon 1.5" stand offs. Just held it up to the bottom of the plane, marked the holes and drilled trough the floor boards. Best thing I ever did in terms of cooling. I never see temps over 165 now and in the winter I have to run aluminum tape over about 1/2 the radiator to get temps over 140. If you zoom in on the pic, you can see the stand offs to get the radiator a little lower in the slip stream.

Leni, Im putting the same type of radiator on my Skyraider,should it be mounted on rubber mounts or does the standoffs youmade have enough flexability? I was wondering how much drag these type create with it hanging out in the airstream like that.In my case I dont have any options as I dont have any room in my cowl for any other style. Thanks Randy

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Posted

Leni, Im putting the same type of radiator on my Skyraider,should it be mounted on rubber mounts or does the standoffs youmade have enough flexability? I was wondering how much drag these type create with it hanging out in the airstream like that.In my case I dont have any options as I dont have any room in my cowl for any other style. Thanks Randy

no need for rubber mounts. Atleast, non of the ones I have seen installed had rubber mounts on them. I am not sure what the drag does to slow you down, I dont think I really noticed any speed reduction when I did mine. If I did it may have been 1-2 MPH. Not enough for me to loose sleep over. I did however loose sleep and a bit of nerves when I was trying to climb high enough to cross the inlet but could not go over 5600 RPM or climb at more than 50-70 FPM or I would see temps over 220. That was when I decided that the belly mount would be worth it at any cost :lol:

:BC:

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Posted

Look at the cool scoop/faring on my Kitfox. If you are worried about drag, get one of these...

post-36-12730157489592_thumb.jpg

post-36-1273015892844_thumb.jpg

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Posted

I have been given a heater core from a school bus that is 9"X2"X32" overall it appears that it will just fit the width of my Model A I am sure that I will still need to angle it to cut down on drag , or maybe not, any ideas?

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Posted

9"X2"X32"

That would probably cool a Big-Block Chevy! I think you would have a hard time maintaining operating temperature on a Rotax...

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Posted

Ya, I was kind of thinking that myself,the core is actually abit smaller but this is the biggest heater core I have ever seen. I looked at a Metro and a Yugo in the junkyard and there radiators were smaller, It looks like its time to lay out some cash. Trying to get my flight lessons and airplane to finish up about the same time looks like flight is going to win and try not to spend too much renting the Ercoupe. The FBO where I am getting my lessons has both a !&@ and an ercoupe both rent for $75 an hour wet. Instruction $25 an hour and I have already finished ground school.

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Posted

I have been given a heater core from a school bus that is 9"X2"X32" overall it appears that it will just fit the width of my Model A I am sure that I will still need to angle it to cut down on drag , or maybe not, any ideas?

You could take it to a radiator shop and have it cut down pretty cheap. I had one built right down the road from my house and I think it was around 125 to 150 bucks, been a few years so I cant remember for sure. Took the guy a day from when I brother dropped off his bent up one (landing gear folded on landing and the radiator was no longer usable) to me picking it up at the shop and having it bolted on.

:BC:

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Posted

Ya, I was kind of thinking that myself,the core is actually abit smaller but this is the biggest heater core I have ever seen. I looked at a Metro and a Yugo in the junkyard and there radiators were smaller, It looks like its time to lay out some cash. Trying to get my flight lessons and airplane to finish up about the same time looks like flight is going to win and try not to spend too much renting the Ercoupe. The FBO where I am getting my lessons has both a !&@ and an ercoupe both rent for $75 an hour wet. Instruction $25 an hour and I have already finished ground school.

I bought my radiator from Kitfox, It was 240.00 plus freight.It looks just like the one from Rotax but almost half the cost.Its 20 1/2 X 5 1/4 X 2.It was built for the 582 or the 912. Randy

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Posted

My radiator man said if I can come up with workable tanks he can put any size core I want in them, a buddy is going to give me a couple of radiators off a YZ 250 lets see if they are a closer match. by the way that was an ercoupe and a 172 both rent for $75 anhour wet going up tomorrow until our asses get too sore.

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Posted

I put mine on using teflon 1.5" stand offs. Just held it up to the bottom of the plane, marked the holes and drilled trough the floor boards. Best thing I ever did in terms of cooling. I never see temps over 165 now and in the winter I have to run aluminum tape over about 1/2 the radiator to get temps over 140. If you zoom in on the pic, you can see the stand offs to get the radiator a little lower in the slip stream.

hello,

I've got in my kit 2 radiators, the classic big one to put inside and an other like the one you've put outside, do you thing i can go only with the belly mont so i can avoid holes on cooling and inside mounting ? seem to be much more simple to do and ligther weigh ::)

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Posted

hello,

I've got in my kit 2 radiators, the classic big one to put inside and an other like the one you've put outside, do you thing i can go only with the belly mont so i can avoid holes on cooling and inside mounting ? seem to be much more simple to do and ligther weigh ::)

Yes, alot of guys went to just the belly mount radiator. I have not had any issues with mine since I went with just the belly mount!

:BC:

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