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Spaghettiohead
05-06-2016, 01:08 PM
Heyy all,

I've got a model 3 w/582 that I'm looking to go through - a modest rebuild and engine change. Ultimately I want to be a 2 Kitfox family, and plan on using the experience on my 3 to build a 7SS. In the meantime though, I'm looking for advice on how to best make the 3 meet my needs.

I'm set on getting away from the 2-stroke world. The 582 has been rock solid, but it's the classic "it's not you, it's me" deal. I was originally thinking of changing over to a 912 setup, but the more I think of it, the more I am leaning towards an R2800. Has that been done to a KF3? I love the idea of low and slow with a radial soundtrack. I'm already going to be replacing the gear, brakes, and tailwheel, so I can likely add enough clearance to swing a larger prop. That brings up two major questions in my mind: 1) with the current setup, I already need tape between the elevator and rear stab surfaces to get a good three-point attitude. Will I need to add weight to the tail? And 2) Will the current tail feathers give me enough authority both in pitch and yaw to handle the larger engine? If not - can I enlarge the rear stabilizer, maybe cut and weld in a model 4 tail?

Any advice and suggestions are appreciated, thanks!

Esser
05-06-2016, 01:28 PM
Not to discourage but the Rotec is a pretty heavy engine. A guy on here built a new model Kitfox with the R2800 and he promptly converted it to an O-200 set up at considerable costs and time. I'm not exactly sure why.

I believe there was a model IV that had a Rotec conversion but someone else will have to chime in to fill you in on that.

Good luck!

Av8r3400
05-06-2016, 01:52 PM
The Rotec radial is 225# plus, where your 582 is in the 75# range. That's a lot of weight on the nose of a III.

There are guys on the forum (SkySteve?) who have done 912 engines on early planes, I'm sure they will chime in with advise on what was needed to make it work.

SkySteve
05-06-2016, 04:12 PM
Yes, my model 134 has the 912, 80hp. Works great. Dan Denny installed it.

Spaghettiohead
05-07-2016, 02:42 PM
SkySteve, do you require any ballast in the tail? Is the airframe on the 3 similar enough to a 4 that it can handle the heavy motor? I'm not looking to be practical, just want to maximize enjoyment. My next Kitfox will be the light and fast machine.

Peteohms
05-07-2016, 03:53 PM
https://www.facebook.com/photo.php?fbid=10208041435306946&set=pcb.10153392593256627&type=3&theater

Vernon motor might work.

jrevens
05-07-2016, 04:03 PM
https://www.facebook.com/photo.php?fbid=10208041435306946&set=pcb.10153392593256627&type=3&theater

Vernon motor might work.

Isn't that cool! What a pretty little airplane!

SkySteve
05-07-2016, 05:36 PM
SkySteve, do you require any ballast in the tail?

My airframe is a model 1 and it handles the 912 just fine. I had to move the battery to the back of the fuselage and behind that add about 12 lbs of lead, but that was to accommodate the extra forward weight of a nosewheel. That's how you spell
E-N-J-O-Y-M-E-N-T!!

azsportpilot
05-08-2016, 08:09 PM
off the subject of engine selection, but....

what does the tape do?
do most model 3's have the tape?

I am instructing someone in a 3, he recently resprayed the tail and told me it had tape which he removed for the paint work and did not re-apply the tape after

Av8r_Sed
05-08-2016, 08:18 PM
I'm one of the many who use the tape to seal the gap between the horizontal stab and elevator. It definitely provides more elevator authority into the flare while landing.