J3 Questions

[Grant]

As many of you know I have a scout project that I am working on. That being my main project and it has a short term completion goal. Like always as soon as you make a decision on something like that and write the check, then something else comes along. So to make a long story short I am about to have a J3 project too & I have a few questions. This deal was too good to pass up so I'll just leave it sit til I have time to finish it.

1. Extended gear, is it available for the J3?
2. Can a wood spar wing be converted to a metal spar? (it has new Dakota ribs/wing is not assembled)
3. Are the original wheels worth much?
4. 65, 75, 85, or 90 ( there is a lot of knowledge out there on this one, I want to swing a seaplane prop)
5. I have heard of the "artic heater" anybody know what this is?
6. Lang tail wheel or Scott 3200? (tail spring size?)

Thanks for the input. I know a guy could look all this up, but I like to hear opinions too.

 

[Amy]

As many of you know I have a scout project that I am working on. That being my main project and it has a short term completion goal. Like always as soon as you make a decision on something like that and write the check, then something else comes along. So to make a long story short I am about to have a J3 project too & I have a few questions. This deal was too good to pass up so I'll just leave it sit til I have time to finish it.

2. Can a wood spar wing be converted to a metal spar? (it has new Dakota ribs/wing is not assembled)
5. I have heard of the "artic heater" anybody know what this is?

2.) No. The spacing on the rib for the wood spar is different than for the metal spar. Wood spar ribs will not fit correctly on a metal spar.
5.) It's a muff around the exhaust (I thought I had a picture somewhere, but not sure where). The one I saw had it mounted on the left side.

Good luck project maniac!

--Amy

 

[behindpropellers]

As many of you know I have a scout project that I am working on. That being my main project and it has a short term completion goal. Like always as soon as you make a decision on something like that and write the check, then something else comes along. So to make a long story short I am about to have a J3 project too & I have a few questions. This deal was too good to pass up so I'll just leave it sit til I have time to finish it.

1. Extended gear, is it available for the J3?
2. Can a wood spar wing be converted to a metal spar? (it has new Dakota ribs/wing is not assembled)
3. Are the original wheels worth much?
4. 65, 75, 85, or 90 ( there is a lot of knowledge out there on this one, I want to swing a seaplane prop)
5. I have heard of the "artic heater" anybody know what this is?
6. Lang tail wheel or Scott 3200? (tail spring size?)

Thanks for the input. I know a guy could look all this up, but I like to hear opinions too.

Plenty of J-3's out there that people rebuilt wanting a supercub. I would rebuild it stock or minimal changes and sell it for a supercub.

 

[Longwinglover]

As many of you know I have a scout project that I am working on. That being my main project and it has a short term completion goal. Like always as soon as you make a decision on something like that and write the check, then something else comes along. So to make a long story short I am about to have a J3 project too & I have a few questions. This deal was too good to pass up so I'll just leave it sit til I have time to finish it.

1. Extended gear, is it available for the J3? Currently available by field approval only. PA-18 gear fits.
2. Can a wood spar wing be converted to a metal spar? (it has new Dakota ribs/wing is not assembled) Only been done a million times, but there is no clear authority to do it. The J3C was made with both types and the fit is physically interchangeable. J3F and L were only ever produced with wood spars.
3. Are the original wheels worth much? Yes and no. Depends on how badly someone wants them.
4. 65, 75, 85, or 90 ( there is a lot of knowledge out there on this one, I want to swing a seaplane prop) Weight of the engines are within a couple pounds of each other. More power is usually better but more power often necessitates more gas (wing tank) and you don't have much useful load in a J3 as it is. No gross weight increase above 1220 available. Installation of Continental engine on J3For L requires an STC - no big deal.
5. I have heard of the "artic heater" anybody know what this is? A couple more soup cans wrapped around the left hand headder. Heat in a J3 is an illusion.
6. Lang tail wheel or Scott 3200? (tail spring size?) Smaller and lighter is better. Lang is readily avaliable even new. Scott 2000 / 3-24 works well too.

J3's are planes that just do better when light and mostly stock. More power is always better. A big handicap is the max GW of 1220. When you start adding mods you increase the empty weight and even a little bit hurts when your useful is ~450lbs at best.

John Scott

Thanks for the input. I know a guy could look all this up, but I like to hear opinions too.

.... .... ....

 

[bob turner]

Unlike a Super Cub, where modifications out the gazoo increase the value, a J-3 that gets lots of mods ultimately goes down in value. The only two mods I would consider are Grove brakes for the original wheels and reservoir master cylinders.

That is actually not true - I approve of more glass, a-la L-4, and my Bear is 150% original size. I also changed the colors slightly and left the wing numbers off. And I cannot argue with an 85 with the O-200 crank or the Steve's gascolator.

Original landing gear and wheels/brakes are more than adequate for any sensible use of a J-3. Heavy duty gear and all the things that go with it will put a real dent in your performance.

Opinion, of course.

 

[bob turner]

John posted while I was typing. I agree about 100% with him. The J-3, PA-11, and the PA 18-95 are wonderful airplanes and deserve to be restored, not hot rodded. Still opinion.

 

[Grant]

I don't plan on doing tons of mods. I just wanted to update it. Since the wings are disassembled I thought it would be a value added thing to go with a aluminum spar.

The extended gear was a thought because I had seen one that looked like it was on extended gear & it looked pretty nice.

The engine is the big kicker. I have heard a stock j3 with a 90hp is the cats ass.

VGs?

Thoughts?

I would not add any electrical at all. I will do the grove wheels & brakes.

 

[Clay Hammond]

I'd like to build one up like the Prospectors that were built under license in Canada. Also this one that I saw at OSH last year (which appears to have extended gear perhaps):



With this neat front seat locker for when i was solo:



When dad picked up Cub #2 to fill in while Cub #1 was waiting for rebuild, Nate was in process of tearing his Champ down for rebuild as well. So as not to suffer his powerplant by atrophy, we went through the process of bolting it onto the Cub so that it could keep running. Went from an anemic 65hp Cont to a Super-85 built up by Nate using Don Sword mods and STC's. night and day difference and the absolute cat's ass if you're in the airplane to have fun.

 

[Nathan K. Hammond]

1. Extended gear, is it available for the J3?
2. Can a wood spar wing be converted to a metal spar? (it has new Dakota ribs/wing is not assembled)
3. Are the original wheels worth much?
4. 65, 75, 85, or 90 ( there is a lot of knowledge out there on this one, I want to swing a seaplane prop)
5. I have heard of the "artic heater" anybody know what this is?
6. Lang tail wheel or Scott 3200?

1. Field approval. I've seen a "tall gear" that is an inch or two higher, but can never find any mention or paperwork.

2. Interchangeable; some would see it as a logbook entry since they're on the same TCDS.

3. Marginal with original expander-tube brakes. Grove disk brake convention makes them better than Cleveland's. With Groves and 25" Goodyears, they're marginal braking. If you're going with big tires, junk them and get some 6" wheels; cheaper in the long run and more options for tires (but doesn't have a good look with 6.00x6 tires (opinion).)

4. 90 or Super-85. 90 has a better cam with most torque, but are hard and expensive to find. Super-85 has more horsepower, cheaper to build, and flys the same as a 90. At least to me. Take a hard look at props; we're running a brand new Mac 71/46 and it pulls like a beast. Tried a GK Sensenich, and an old thin Mac 74/42 but neither got it off the ground consistently shorter and all were slower by 7-10mph. More hp will need wing tanks; 1:55 until empty with Super-85 @ 2300rpm. That's fine for dinking around locally, but limited for X/C.

5. Better heater in theory. It's only a theory.

6. Lang, cheaper and lighter. Only time you'll want the 3200 is on a mud bog, but the J-3s tail is light and easy to pickup with power and forward stick.

nkh

 

[MainlandCub]

3. Marginal with original expander-tube brakes. Grove disk brake convention makes them better than Cleveland's. With Groves and 25" Goodyears, they're marginal braking. If you're going with big tires, junk them and get some 6" wheels; cheaper in the long run and more options for tires (but doesn't have a good look with 6.00x6 tires (opinion).)

nkh

It is a pity there are not larger tyres to go on the original 4" wheels; they are a really good wheel and the Grove disc conversion sorts out the brake issue. Anyone know if there's any chance of Alaska Bushwheel or someone developing a larger tyre? They used to exist didn't they? Or are there some already I don't know about?

Andrew.

 

[bob turner]

No - the Grove brake is designed to and does give the same performance as the stock Hayes brake. I put Grove on one side and stock on the other (statute of limitations is over, thanks) and did 500 heavy brake landings. The advantage of Grove is ease of maintenance. It will give you identical performance to the Cleveland 30-19, which is plenty good for retractable Cherokees and Mooney 201s. I have them on my Super Decathlon.

The extended gear and big tires are useful in something that is going to haul carcasses out of the tundra, but if you are trying to impress the non-Cub pilots at your paved field, you are under an illusion. A J-3 does not have the power or the load carrying capability to do anything useful in the bush, so doing all that will do everything the STC says, including reducing climb performance, cruise, decreasing crosswind capability and increasing takeoff roll - you can read it on the front page of the STC. Non-Cub pilots have been heard to say: "Is that a cartoon airplane?" And that was with only 29's installed.

And there were 26" tires that fit the Hayes wheel. I think there may have been an adapter. We had one in the 1970s.

 

[Douten]

J-3

Grant, if you plan to sell it off when done origional is better but if you plan to keep it and play around the patch I would do some mods ( see chris nesings pa-11 rebuild recomadations) Converting to an 11 will give you front seat solo, the aluminum spar wings and and two tanks would be nice but adds weight ( I still wish I had bit the bullet and put the second tank in on my rebuild of my 11 ). c-90-8 if you can find one is a great engine and the 85 stroker is proving itself from what I've seen. I have extended wings on my 11 and think that may be why it performs pretty good for being a heavy little plane. keep it as light as you can also, I run the Goodyear 25x11x4 tires and have no problem with the stock brakes (I can skid my wheels on runup). supercub trim, elevator control, second tail handle for float/ski operations, scott non swiveling tail wheel is very light. Good luck with both projects

 

[Longwinglover]

Grant,

Wrap your head around the fact that the J3C (Continental engine from the factory), J3F (Franklin engine from the factory) and J3L (Lycoming engine from the factory) are three different Type Certificates. J3F and L production ceased at the beginning of WWII but the J3C continued in the form of the L4 and post war J3. It is advisable to find out quickly which model you have as all available mods and STC's don't apply to all models.

There is now an STC to install Continental engines of the J3F and L (and concurrently raise the GW to 1220lbs). If your project is an F or L with a Continental previously installed by Field Approval, legally speaking your GW is no more than 1170.

The new Dakota ribs you get (got?) are probably for wood spars. They are different from the ribs for aluminum spars. New wood spars are available. There is no strength (weight carrying / GW) difference in wood vs. aluminum. There is no mention of spar material in any of the TC's but wing types (wood spar non-freise aileron, wood spar freise aileron and aluminum spar) are serial number specific in the Piper parts catalogs.

Maybe Amy can see if the full metal spar wing (kit or assembled) is applicable to all three TC's (A691, A692 and A698).

John Scott

 

[fly_cubs]

Grant,

Wrap your head around the fact that the J3C (Continental engine from the factory), J3F (Franklin engine from the factory) and J3L (Lycoming engine from the factory) are three different Type Certificates. J3F and L production ceased at the beginning of WWII but the J3C continued in the form of the L4 and post war J3. It is advisable to find out quickly which model you have as all available mods and STC's don't apply to all models.

There is now an STC to install Continental engines of the J3F and L (and concurrently raise the GW to 1220lbs). If your project is an F or L with a Continental previously installed by Field Approval, legally speaking your GW is no more than 1170.

The new Dakota ribs you get (got?) are probably for wood spars. They are different from the ribs for aluminum spars. New wood spars are available. There is no strength (weight carrying / GW) difference in wood vs. aluminum. There is no mention of spar material in any of the TC's but wing types (wood spar non-freise aileron, wood spar freise aileron and aluminum spar) are serial number specific in the Piper parts catalogs.

Maybe Amy can see if the full metal spar wing (kit or assembled) is applicable to all three TC's (A691, A692 and A698).

John Scott

It's also important to remember that you can't just slide the wood spar out of the wing and put a metal one on- the construction of the two wings is completely different.

When I rebuilt mine, I went back with douglas fir wood spars and new ribs and metal LE, TE, and false spars from dakota cub. It's a nice ride wings flex a bit more than the metal spar cubs I've flown. The only thing I'd try to do different next time is use spruce spars (lighter) and the .020 2024 t3 skins from univair - again to save some weight.

 

[Grant]

Clay,
Thats the one I saw. It is based at one of the airports here but I don't know who owns it. It seems practical to me.

 

[behindpropellers]

4. 65, 75, 85, or 90 ( there is a lot of knowledge out there on this one, I want to swing a seaplane prop)

Grant,

If you want to go to a C-85 or C-90 you might look around for a C-75 which you can convert. C-75 & 85 cranks are the same.

Tim

 

[Amy]

2. Can a wood spar wing be converted to a metal spar? (it has new Dakota ribs/wing is not assembled)

I should clarify my previous statement so as to avoid confusion. The spar dimensions for a wood spar are different from the metal spar. As such, wood spar ribs will not fit onto a metal spar and vice-versa. If you wanted to convert to a metal spar, that would mean new ribs as well. Personally, I am not concerned about wood spar airplanes and I don't think I've met a J3 owner who refuses to have wood spars (though I am sure they exist). Of course, they should be properly inspected and you should familiarize yourself with proper construction, varnishing, and repairs, but they have worked for decades. 99% of the J3 buyers in the lower 48 are not going to store the airplane outside so concerns of rot are effectively eliminated (opinion).

It is true that a metal spar might help resale value strictly due to a new buyer's impression of wood vs. metal. In that case, I'd price out what I needed to have a metal spar wing and weigh it against the increased resale value. Of course, if you are going to fly it for a while before you sell it, consider what you want as well.

I also think it behooves you to install a wing tank right away, especially if you are considering a bigger engine. Yes, it adds weight, but it's easy to install now and fly around with it empty. It's a pain to add later, looks funny because of the modifications performed on an otherwise complete aircraft, and does add resale value. When we flew 5 airplanes out as a gaggle to Sentimental Journey in 2010, we had one 75-hp J3 without a wing tank. Its pilot had an auxiliary tank in the front seat and spent 10.5 hours there and 9.6 hours back squeezing a hand pump ball to keep up with the other two wing tank-equipped J3s, Luscombe, and PA-12. Glad it wasn't me. It would be a seat cushion clincher, for instance, to take a no wing tank J3 down the lakefront corridor in Chicago.

Best of luck sir--hope you rope Jason E. into it all

--Amy

 

[Amy]

I forgot! You should also strongly consider joining the Cub Club (www.cub-club.com). If it saves you one hour of questions with your A & P, it has paid for itself (even if you pay him in beer). The most recent issue, November/December, has the first of a two-part article on adding shoulder harnesses, for instance. If you could add shoulder harnesses in a usable manner, that would also help resale value. They also have back issues (you can download the index for free and find back issues by topic) as a set or individual copies, and prints.

 

[cubdriver2]

I also have the stock brakes and 25" Goodyears that I can lock up. With a little scat the heater works fine if you deliver the hot air to where you need it instead of letting it follow the floor to the back of the airplane.

Glenn

 

[flybynite]

Grant,

Here is the Artic (sic) Heater from Wag Aero. A 65-85 hp only puts out so much heat so the effectiveness is marginal.

http://store.wagaero.com/product_info.php?products_id=4178

Here it is installed on the exhaust manifold.



There are enough air leaks in the cabin of this plane that pretty much overcome the ability of the heater to keep up. I don't know if it would fit under the cowl of an 11 either.

Cheers
Wayne

 

[cubunltd]

Grant, contact me by email and I'll send you pics of a couple of J3's I did with some neat mods that don't increase the weight and keep the J3 looking stock. jswalt@comcast.net

John

 

[duckhunter10]

arctic heater really dildn't do much for me, I really like the vg's on mine, extend the baggage area behind the rear seat, running 25x11x4 that i like(i have a spare set i'd sell) they do extend your take-off by 12-20% and lower your climb but it's a trade off i can live with since i land on sandbars and soft fields a lot, 85 or 90 on the motor (i'm conveting my 85 to an 0200 this spring, shoulder harnesses also a good idea

 

[bob turner]

I don't think I've met a J3 owner who refuses to have wood spars (though I am sure they exist).

Amy has not met me, so she can still say that. Every single wood spar wing I have participated in recovering needed spar work. Metal spar wings are available, and a metal spar Cub costs no more than a comparable wood spar Cub. No way would I opt for wood.

My Super D has wood spars, and every year it is time to open that sucker up and spend hours of delightful time with a bendalight and mirror, backed up with a proctoscope of limited utility. Never anything wrong with them, since they were all replaced with new at the first rebuild. If I were rich, I would wheel the thing in to ACA and get metal spar wings.

 

[bob turner]

By the way, I have built a metal spar wing from scraps. Dakota Cub was delightful to work with for the spare pieces. Hardest part was forming leading edges from .020 T-3. Originals were .016-O

 

[tempdoug]

And if your looking for a climb prop, i have a wood sensenich 76-36 in mint condition for a 1/3 off new price, delivered. bought from jim drometer at belle plaine, minnesota.

 

[Amy]

I don't think I've met a J3 owner who refuses to have wood spars (though I am sure they exist).

Amy has not met me, so she can still say that. Every single wood spar wing I have participated in recovering needed spar work. Metal spar wings are available, and a metal spar Cub costs no more than a comparable wood spar Cub. No way would I opt for wood.

I know of one that exists now though! 8) If I were in the position of doing a complete rebuild for resale, I think it would make the most sense to use a metal spar. However, if I had everything to make a wood spar wing and was paying for the project accordingly, I might have a hard time deciding to backpedal and buy new ribs and spars on top of paying for the wing parts included with the project.

 

[kevin]

I would keep the wood spars. There is nothing at all wrong with them. As for brakes, I would install the Grove if you wanted more modern brakes. I would seriously look into the Don's Dream Machinne STC or perhaps a C-90. Both would probably be a good choice. I would add the wing tank now. I would not do anything else to the J3. Keep it light for higher useful load. I would keep the stock length gear and use a Lang tailwheel. The Scott 3200 is overkill on this plane.

 

[ndill]

GRANT, I see you've met the light weight Mafia.:lol:

 

[bob turner]

If the Heroes tank is available (Air Energy) that's the one I would use. Folks are right - an x-c in a J-3 now requires a wing tank. I did my first seven transcontinentals without a tank, but that is now impossible due to airport closings and lack of fuel at some critical airports.

If your bungees sag with a loaded airplane sitting still, I agree you need new 1280HDs. If you are going to take your airplane into and out of really, really rough fields, then the 6:00x6 will give you the option of Bushwheels. Normal J-3 tires will handle farm fields just fine.

I fly VGs all the time - both styles. Most of the local Super Cubs have them, although we got quite a bit of experience with stock wings first. I personally cannot see the advantage, but I do not believe there are disadvantages beyond cost and cleaning the leading edges.

A Super Cub is a much better airplane to rig for off-airport stuff.

All opinion.

 

[Beach Bum]

I had a beautiful 1941 J3. Mods to do are the C90 from Don's Dream Machines, metal prop, 12 gal aux fuel tank. My son flying in formation in the J3 after the updates:

http://www.youtube.com/watch?v=KlGzKR09zOg

Sold it in a month for $42K. Many people wanted the 12 gal aux tank.