Model II foibles - Rudders and Radiators

[Osprey220]

Hi All,

Well now with a little over 40 hours on our Grey Headed 582 Model 2 Kitfox, I have most of the initial problems licked.

The scariest was full on wing flutter - YIKES! But that seems to have been taken care of by tightening all control linkages and shoulder bearings.

I am still having trouble with temperatures. Eliminating air leakage around the shrouded radiator and moving to distilled water seems to have helped sufficiently for days cooler than 85. But those days are becoming few here in central CA.

Anyone have experience with larger radiators for better water cooling?


Another issue is the tiny tail. The plane is squirrelly - but much more of an issue is losing sufficient elevator authority under 45 mph to comfortably push low speed landing performance.

Any suggestions for retrofitting larger rudder and elevator control surfaces?

-Owen

[avidflyer]

Did you try lowering the radiator an inch or maybe a bit more? Seen it help before. JImChuk

[HighWing]

In the old email list days, lowering the radiator - or raising it - was a semiannual routine for a lot of the 582 guys.

[Esser]

You can definitely enlarge those surfaces. Do you have gap seals on the elevator? I’m not too familiar with the II but more people should chime in

[Osprey220]

Just thought I should add a link to a YouTube I made a few weeks ago.

https://youtu.be/4aAJnWaqhUg

Keep the temp and tail suggestions coming!

Cheers,
Owen

[vetdrem]

I added gap seals to the elevator of my model III to improve elevator authority. I would run out of elevator and could not flare because the stick was all the way back already. The gap seals made a big difference. Replacing/enlarging the tail surfaces is pretty major surgery, I think I would try the seals first and see if it makes it ENOUGH better.

I used leading edge tape from ACS, half lapped sticky-to-sticky then attached to horiz. stab and to elevator. Took about 10 minutes.

[cubtractor]

I added gap seals to rudder and elevator, plus installed VG's to the underside of the horizontal stabs. Made a big difference.

[Guy Buchanan]

Back in my 582 days I ran no shroud and 1" lowered on the radiator. Otherwise I'd overheat on the ground. With that system I could climb out of Fresno on a 115F day, very carefully.

Make sure both the rudder and elevator are gap sealed. It makes a noticeable difference. You can do tape on both, but the rudder looks much better with a painted solid seal. (Could do painted fabric, I guess.)

[Osprey220]

Thanks for the gap seal suggestions.

They are not sealed so I will tape seal and test this weekend.

Regarding temps - the opening of the shroud is ~2" below the bottom of the fuselage - this is not enough?

Any suggestions on larger radiators?

Cheers,
Owen

[Guy Buchanan]

OK I have to say this: Make sure you have full control authority after you gap seal. (Glider pilot awareness moment.)

I found the shroud increased ground temps so I ditched it. I also used the stock radiator, just 1" lower, on stands. You could do the same with a larger radiator and no stands but I don't think you'll need to.

Best would be to build a better shroud, that really works. Big job, but worth it in the long run.

[Dusty]

The radiator hanging underneath isn't the best place as it must creat a lot of drag,also it is trying to cool the engine using air off the exhaust dumping through.I guess lowering it lets some of the hot air bypass at the expense of more dragThese early machines weren't designed to be as fast as I he current incarnation.There was a YouTube video a few years back of a chap modifying his cowl to encourage the heat to exit away from the radiator,a but ugly but functional.