Skycat80

Hey guys, I just finished building my Uproar kit and realized that there isn't much room in the tank compartment for a very big tank. I have an O.S. .40 FP on it. I forgot to take measurements of the tank compartment before I went to the hobby shop to get the last few things I needed to finish the plane. I picked up a 6oz and an 8oz tank hoping the 8oz would fit. It wouldn't. With foam around the tank, I had to really squeeze the 6oz in there.
What size tanks are you guy using for your Uproars? Also, with a 40FP, any input as to what kind of flight times I can expect with the 6oz tank would be great.
One last thing... Can anyone give me any impressions of the O.S. 40FP and what you think of them. I know they're an older model, I just didn't know what you guys thought of them.
Thanks in advance for any input!
Ryan

hugger-4641

My Feedback: (6)

O.S, 40 Fp will be plenty of engine for the Uproar. It's a reliable entry level engine. It is not a ringed piston and has bushings instead of bearings, so it is not high performance and will not last as long as other engines like a .46 ax for instance. But if you take care of it and don't run it lean, it will last a long time. I have two of them on trainers that I teach with that have been running strong for over 6 years now, and I probably run 2 to 3 gallons of fuel a year thru each one. With a six oz fuel tank, you can probably expect 8 to 10 min of flight. If you can do a little sawing and get the 8oz tank to fit, I would recommend it. You don't say what type of tank you bought, but there are a variety of styles of tanks available and some are completely flexible. With the right style tank, you should be able to get a 10 to 12 oz tank in that plane, which would give you 15 to 20 min of flight.

P.s. A few tips with that engine:
The best prop I've found is 10 x 6. I have used 9 x 6 but the 10 x 6 is a better choice for general sport flying.
Don't use fuel with any more than 15% nitro, it's not needed.
Make sure the mounting screws under the base of the carb are tight. These are prone to get loose and let air in, which makes tuning unpredictable if not impossible.
In cold weather, a hot plug: O.S. #6 (formerly called A3) will make idle and tuning a little easier.
In hot weather use a medium #8, or cold plug #10 (formerly A-5) and they will make more power and last longer.

Skycat80

Hugger, thanks a lot for the info and tips on the motor. I will start looking for a flexible tank for for it. I was thinking 6oz seemed a bit small, but I haven't flown a .40 yet. The kit called for a 6-8 oz tank, so I figured that'd be a good place to start. The throttle linkage running through the tank compartment cuts about 1/4" - 1/2" off my space, so I think a flexible tank would be great. Thanks again for the great tips and info!

hugger-4641

My Feedback: (6)

Don't be afraid to improvise a little. If you need to squash one side of the tank a little to get it to fit past the throttle linkage, it will be fine as long as the fuel tubes are oriented correctly, you don't poke a hole in the tank itself, and you don't distort the bung seal and cause it to leak. I have had to do this on occasion and I usually slip a tonge supressor or popsicle stick along side the tank to make it easier to remove later if need be.

PatrickCurry

My Feedback: (20)

I've used empty spice bottles to make fuel tanks and they sometimes fit better because they're round. You can find a lot of ideas for making your own tank here. Also, if you can get it to fit, jam the 8 oz tank in there without the foam. Then put a couple squirts of Armorall in your gallon of fuel and use a sintered tank clunk like this and that'll keep your fuel from foaming and bubbles being pulled into your engine. This is probably bad advice, but hey.....

DGrant

My Feedback: (4)

A 6oz tank is what is used in these pretty much across the board.

Have you looked at RICKSTUBBZZ long standing Uproar thread? Theres everything Uproar in there... great info on these fun planes...

http://www.rcuniverse.com/forum/kit-...-40-build.html

An OS FP.40 is a real nice simple work horse of an engine that will do just fine... oldie but goodie... and if you have one all the better. Use it.. Good luck.

Skycat80

I found a round 8oz tank at my LHS. I was able to squeeze it in there. Thanks again for the great ideas and suggestions! I'll post video of the maiden hopefully soon.

Tom Nied

Was it a Sullivan Flex Tank?

Skycat80

Tom, it wasn't a Sullivan. I did look at those but they didn't have round flex tanks at the hobby shop I was at. The one I ended up getting was still in the original packaging, but the label was really old and I didn't pay very close attention to what brand it was.

Tom Nied

But you were able to get an 8oz tank into it? I'm coming up to the Uproar fuselage build and that's the one thing I haven't bought. With a Magnum XLS .46 on mine, I'm hoping to get at least an 8oz into it.

flybyjohn

My Feedback: (2)

My uproar is on floats and I have a 46 tower in it. I put a 8oz in mine, always have fuel after 8 minutes of flight. I do have a fun 51 which is the same type of flying plane and a thunder tiger 46 on it with 3.75x12 prop. and it has a 6 oz tank. I don't fly full throttle all the time but I always seam to get a good solid 8 minutes of flight and then the tank is almost empty. I can see the fuel level in that tank on a slow flyby though and so I keep an eye on it. I think your 6 oz will be fine. Fly the first time at 5 minutes and then check how much fuel is left, then refuel and go 6 and recheck. After 5 or so flights, you will get a feel for how long you should go. When I get to one crank of fuel on the fuel pump left, I am getting a little too close. For me, 8 minutes is plenty of time for each flight, it only takes a few minutes to refuel and be back in the air. If you want to fly longer than 8 minutes or are heavy on the throttle, then try and get the 8 oz in there.


whoops I see you already got the 8 oz in there, your good to go.

buzzard bait

You might try an 11x4 prop on that engine/plane just to see how it compares to the 10x6. I flew a 40 FP on a trainer years ago and was surprised how well it did on an 11x5. Jim

Skycat80

Actually Tom, I just went and looked at it and it was a round, seamless Sullivan. Their old packaging must have thrown me off. Do yourself a favor and pay close attention to how far to the left (if you're looking straight at the firewall from the front of the plane) or starboard side , you drill your hole for your throttle linkage. If you can make it work, the farther to the left inside that compartment it goes, the more room you'll have for your tank. That was the limiting factor on mine. I was able to squeeze it in there without bowing the linkage too bad. With the 8oz round tank, you'll need to run the cap pretty much out the hole in the firewall toward your motor. If you want a picture, I can send you one. Just let me know.

hugger-4641

My Feedback: (6)

I started with an O.S. .46 Ax on my Dazzler and it was really over-powered for sport flying, so I took it off and put a TT Pro .40 on it. That was the perfect match for me. The TT Pro .40 is quite a step up from an L.A. or F.P. 40 and would still almost hover, but not as heavy and over powered as the .46.
I have the Magnum .46 xls on another plane, and I would rate it a little lower than the .46 ax as far as performance, but it has been a very strong and reliable engine.

Tom Nied

Thanks for the thoughts. Well, Ive got the Magnum .46 and it's destined for this plane. It's not exactly what I would have pickied, but it has plenty of power.

Tom Nied

Thanks for the thoughts. Well, Ive got the Magnum .46 and it's destined for this plane. It's not exactly what I would have pickied, but it has plenty of power.

Skycat80

I got to maiden it today. As I stated earlier in the post, I have the OS .40 FP and an 8oz tank in it. After a 9 minute flight, I brought it down and checked fuel level and I had a little over half tank left. That was flying wide open almost the entire 9 minutes. I had a steady 15 mph wind with 20-25 mph gusts, so I needed every bit of power I had.
The maiden went pretty well. I had two dead sticks, one nearly fatal, but turned out perfectly. There is a large creek behind the field that was pretty high due to all the melting snow. I didn't know there was a creek back there, it just looked like field, so I brought it down where I thought was all field. The plane literally landed almost vertical on the steep bank of the creek with the rudder about 4" from the water. I could not believe it when I saw it.
The O.S. .40 did pretty well after we got her all dialed in. It certainly isn't a power house, but it will pull the plane around ok. It's hard to tell how it really does until I fly it without all the wind. I have another uproar to build this winter and I'm definitely going to go with a beefier motor for it. I will say that it is a great flying little plane. I'm really happy with it.