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Possibly taking on a hangar queen J3C-85, any advice?

IainR

FRIEND
Underberg, South Africa
Good day all
I have recently come across a J3C-85 which has been in the back of a hangar for 18 years. This will (hopefully) be my first J3 having flown super cubs and various other bits and pieces for years I've been on the look out for something like this but am nervous none the less! Any advice on things to look out for or mods that are must do/nice to do that may well have not been done (eg univair struts, grove disc break conversion, any more?)? Having not flown for so long I am going to be getting the engine opened up and checked as well as the components serviced so will be a good time to do any additional work.
Any advice appreciated!
 
There are no must-do mods. The struts will save money in the long run if you choose Univair. The brakes are only necessary if the originals have failed.

Carefully check for fuselage corrosion, and if wood spar, take a good look at spars. I personally would borescope the engine, and if no serious corrosion can be seen, I would pre-oil and start it.

When you disassemble an engine these days, mechanics want to send all the pieces out. You will get a reground crank and cam, new lifters, re-machined case, new pistons and valves, often new cylinders. Twenty grand. A lot of it is driven by lawyers - but these engines are lawn mowers. They do not generally fly apart, and only quit when the fuel stops flowing.
 
Good day all
I have recently come across a J3C-85 which has been in the back of a hangar for 18 years. This will (hopefully) be my first J3 having flown super cubs and various other bits and pieces for years I've been on the look out for something like this but am nervous none the less! Any advice on things to look out for or mods that are must do/nice to do that may well have not been done (eg univair struts, grove disc break conversion, any more?)? Having not flown for so long I am going to be getting the engine opened up and checked as well as the components serviced so will be a good time to do any additional work.
Any advice appreciated!

Find a good cub mechanic to look it over prior to purchase. 18 years isn't bad but in the wrong environment a lot of damage can happen.

Tim
 
I agree 100% with those guys. However . . .

I bought my first Cub in 1962. Blackwell said $1200. I glanced at it and wrote the check. Then I grabbed a duster pilot to teach me to fly it. They told me later they were laughing at me for not negotiating. I got my license from those guys - didn't even know I was taking a checkride until Talmadge Barber handed me a shot of whiskey and said "congratulations." Very close to 5000 hours in it since then, mostly trouble-free. Eight landings today.

Since then, two more Cubs, two Stinsons, a Mooney - all pretty much by staring at them from ten feet. Don't regret any of them. Helped with two Stearmans, a Waco, several Super Cubs . . . the only ones that did not work out well were the ones that were already a done deal by the time I got there. Always check the empty weight in Super Cubs, especially highly modified birds.

When someone asks for advice, my first comment is to check the paperwork, data plate, alterations, total time, and fly it. That, apparently, does not apply here - at least the flying part. But you should not pay a premium price for an aircraft that has not flown in two decades - it may need $20,000 worth of work! Or worse, a new fuselage! But there is a chance that it is ok, and that you could fly it out of there after a good inspection and pre-oiling (easy; we just hook pressure up to a galley plug and pump until it squirts out all rocker arms).

One of the Stinsons came from my Chief Pilot at America West. We bought it sight-unseen. Beautiful aircraft. It is now up in Alaska somewhere -

For me, buying Cubs is like meeting a new co-pilot. You can almost tell by the way they look at you when you shake hands, whether it will be an easy trip or not.
 
For me, buying Cubs is like meeting a new co-pilot. You can almost tell by the way they look at you when you shake hands, whether it will be an easy trip or not.

Bob, I didn't Quote you completely, but ... if I've learned one thing in all these years ... A lot of these airplanes where not very old when "we" were buying our first ones .. and lets face it, it was a heck of a different world then.. things are different now ..

We were buying 25 year old airplanes. Folks today are buying 70+ year old airplanes ... major difference.

I've never had a "pre-buy".. never had a problem, post purchase.. I've spent my life in aviation.. owned several airplanes.. as much as I "buy" the airplane, I "buy" the seller.. You can tell a lot about the airplane if you study the seller..

The flip side of Bob's First Officer analogy is, he spent along time "learning from his "Captains" ... and passed it on!

This was pretty much the OP (original poster) first post.. Congrats for asking your questions!! Shows your interested in knowing all you can..

As I said earlier... 85hp J3 !! Awesome !!
 
Thanks for the time everyone. I am busy with the logbooks etc and so far nothing overly startling. I am really trying to look out for items that are possibly going to cost a fortune as I get her airworthy so that I can make a fair offer. I had a Twin Comanche which I inherited from my father for a number of years and every now and then some obscure thing would catch us out at annual time and cost a small body part! I now fly my grandfathers Tri-pacer which while softer on the pocket also everynow and then throws a surprise cost. Trying to minimize the surprises as much as possible!
 
Trying to minimize the surprises as much as possible!

Aren't we all, my friend... Aren't we all! And no matter how "perfect" the airplane you buy, or what "pristine" condition it may be in when you buy it, ALL airplanes throw us surprises every now and then. It's nature's way of asking "Do you REALLY want to be a pilot?" LOL

The good thing about a Cub (or any other very "basic" airplane) is that even the big surprises are smaller than with more complex airplanes. Other than the engine, most other things can be put right with copious applications of sweat and blood (plus small-to-medium infusions of capital, of course).

Good luck to you! Hope brings you many hours of happy flying!
 
Having had a chat to my local engine shop, I believe that C85 engine parts are hard to come buy, can anyone confirm this? The shops recomendation was if it needs a over haul, turf the 85 and put in a O200.
 
C85 parts are hard but not impossible to find. Don's Dream Machines has the STC to overhaul the C85 with O200 crank/pistons/cylinders. As far as I know there is no STC to install a full O200 in a J3.
 
My impression (I am currently running three, have a spare, and supervising an assembly) is that everything except the crank and rods is available from someplace near Fresno. The crank STC is expensive but worth it. I finished one 200 hours ago and am delighted.

Univair has an STC for the O-200 in the J3. Check the J3 Cub forum for details.
 
My impression (I am currently running three, have a spare, and supervising an assembly) is that everything except the crank and rods is available from someplace near Fresno. The crank STC is expensive but worth it. I finished one 200 hours ago and am delighted.

Univair has an STC for the O-200 in the J3. Check the J3 Cub forum for details.

Thanks Bob, what crank STC are you refering to if you don't mind my asking?
 
There are two STCs to put the O-200 crank, rods, and pistons in a C-85. Notpositive, but I think Don's Dream Machines and ECI? Bought mine in 1995 for $1200, balanced it for $300 more. Things have changed since then.

Installed it two years ago, and am deliriously happy.
 
There are two STCs to put the O-200 crank, rods, and pistons in a C-85. Notpositive, but I think Don's Dream Machines and ECI? Bought mine in 1995 for $1200, balanced it for $300 more. Things have changed since then. Installed it two years ago, and am deliriously happy.
Thanks very much for the info, do you know if the O-200 STC allows the installation of higher compression pistons to take a C-85 up to 90hp? I seem to remember reading somewhere that it could be done but am not sure if its possible on type certified aircraft.
 
The C-85 Stroker STC's increase the compression from 6.3:1 to 7:1 via longer piston stroke in a similar cylinder. That creates a ~C-90 equivalent due to increased displacement (188>200 ci) and C-90's compression. The C-85 and C-90 cams are slightly different (the STC's retains the C-85 cam). Continental has a SB (M47-16 Supp. 1) that approves converting a C-85 to C-90 as well using C-90 components. There is an unapproved mod that retains the C-85 pistons with the Stroker STC. It raises the compression further to about 8.5:1 but requires chamfering the upper piston to eliminate interference fit.

Gary
 
I remember when talking to the guy from A S S, he said they were putting out somewhere around 93hp.
John
 
Seems to feel about right John. C-90 rated 2475 and 5 min. 2625 @~95hp. C-85 rated 2575 and the Stroker STC retains that limit. It's the added torque that counts I suppose.

Gary
 
The most important check is the wing struts. If it has original struts, then extreme caution is advised. You can land OK with a dead engine, a broken tail wire or inoperative brakes, but not a missing wing. Before sealed struts there was a mod that went on almost every "Cub" banner plane J-3, PA-11, PA12, PA-18 called Bradley safety straps. I lost a friend in Mount Pleasant TX due to strut fork failure, and I've seen loads of water drained out of struts when drilled to weld in the Safety strap bushing. As a minimum, make certain they actually did the strut punch test and didn't pencil whip it. Better yet, install sealed struts. Enjoy your Cub, and spend your money on gas before engine upgrades. The 85 flies well as is.
 
Well I pulled the trigger and have bought her. Now to get her up and running again! Thanks for the help on the thread much appreciated. By the way the unusual "N number" is because she is in South Africa.

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I purchased a J3C-65 last fall that hadn't flown in 15 years. I bore scoped the cylinders and found them to be rust free. The differential compression test was performed cold prior to me ever running the engine. three cylinders were77 over 80, with the last at 73 over 80. I pulled the lift struts, removed the forks and bore scoped and the picture showed clean gray steel. This certainly could have gone the the other way, but am hoping you find yours to be in great condition also. Mine came with the C-90-8 and aluminum spars. I soloed an 85 J3 22 August 1965.
 
Thanks all! I'm sure I will have a fair few questions as I embark on this adventure.
 
Gary having had a look at the aircraft specialities website it states no increase in performance, did you find that to be the case or did you get similar performance to the Don's Dream Machines STC?

Iain the first link claims no increase because it limits their need to change published performance and fuel consumption data. I believe Don's testing showed an increase to the mid-upper 90's hp. That's what I found as well. Power and fuel consumption increased....it has to because the displacement goes from 188 to 201 cubic inches and compression from 6.3:1 to 7.0:1. Move more air through the engine and power/fuel increase.

Earlier I had a C-90 fresh overhaul in a PA-11....static rpm with optical tach checker about 2335. Same prop Sen AK76-2-40 transferred to the Taylorcraft static is 2440. The Taylorcraft has a better airbox (new and tight), air filter (Donaldson), exhaust system (C-150 mufflers), C-90 cam and lifter bodies (per Continental's current 1960 SB 47-16 data), so is better than the Piper exhaust and whatever. Over TCDS static limits but good for floats. Basically the STC turns a C-85 into a C-90. I am pleased.

Gary
 
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