finishing up old project

fit90 Sat Aug 04, 2012 12:04 pm

Several months ago I won a pair of mostly built and one mostly covered House of Balsa Stealth Sports. I finally got sick of one of them clogging up my building board so I finished it up and will hopefully give it its maiden flight today. It will be powered by a never used Black Widow that my local hobbyshop owner found for me. I will be posting pics and a flight report later today.

Bob

fit90 Sat Aug 04, 2012 8:09 pm

Here she is-the ugly duckling of the fleet. When I was finishing it up I got really excited because I found some old neon green Monokote to put some trim on it with. Well, neon Monokote does not age well. As a result, it didn't get any sunburst, checker board or stripes. It flew alright on the Black Widow. After a few tanks I put a Galbreath head/Nelson plug on the engine and that picked it up way more than I had anticipated; but, the run time fell to under two minutes. The plane flies well while the engine is running, but when it quits you need to keep the speed up to keep the controls effective. Since the plane is really draggy this means pointing the nose way down. I might put a tank extender on it some time to extend run times. I will wait and see on that. All in all, it is a good flying plane, just not as responsive as I like. Perhaps if the engine runtime was longer I would enjoy it more. Time will tell.

Bob

**Cribbs74** Sat Aug 04, 2012 9:16 pm

That's a different one! In a good way though Very Happy

Glad it's still in one piece after the maiden. Thanks for sharing.

You know, I had no idea galbreth heads were performance enhancing. I thought they lowered compression. Guess I was wrong!

microflitedude Sat Aug 04, 2012 9:32 pm

How does the engine run in flight, and where is your pickup tube located? I have a black widow on my Cub and it runs terribly once off the ground.

andrew Sat Aug 04, 2012 9:33 pm

cribbs74 wrote:
You know, I had no idea galbreth heads were performance enhancing.

Hmmmm --- I wonder ........? Oh well, probably not. Sad

fit90 Sat Aug 04, 2012 9:42 pm

MFD,

The pick up tube is at the bottom of the tank (6 o'clock). Other than the glowplug, the only other changes were to remove the cam starter (which was missing a piece) and replace it with a zero drag drive plate and starter spring and to remove the needle valve tension spring and use a piece of fuel tubing to seal the needle and secure the fuel tubing with a small, I think either a #2 or #4, washer near the top of the needle. I also replaced the backplate with a new one from Bernie but that was because one of the mounting ears was broken off and installed a new venturi "O" ring in place of the missing one. I ran two tanks (16cc) of fuel through the engine before flying and changed the glowplug out before either the second or third flight. I will get a picture up in the next half an hour.

Bob

fit90 Sat Aug 04, 2012 9:51 pm

here are a few pics. I hope this will clarify things.

finishing up old project Dscn0612

fit90 Sat Aug 04, 2012 9:54 pm

Her is a front pic. I am using Sig Champion 25% as it comes and an APC 5.7X3 cut down to 5X3.

finishing up old project Dscn0614

This particular prop has a fairly light load for a 5X3. This allows the engine to rev a little higher. It seems to like the slightly higher revs.

Bob

fit90 Sat Aug 04, 2012 9:59 pm

Almost forgot, the engine runs great in flight. Better than on the bench because it can unload on the moving plane. It does not like inverted flight, though. I think this is because of the fixed pick up tube and not the engine though.

Bob

**Cribbs74** Sat Aug 04, 2012 11:21 pm

fit90 wrote:Almost forgot, the engine runs great in flight. Better than on the bench because it can unload on the moving plane. It does not like inverted flight, though. I think this is because of the fixed pick up tube and not the engine though.

Bob

Is there room for a clunk tank?

fit90 Sun Aug 05, 2012 12:32 am

No. Last month's engine of the month was supposed to go on this plane but due to CG considerations I had to put the battery and some lead where the fuel tank was going to go. So I went with the original tanked engine design.

Mudhen Sun Aug 05, 2012 11:25 am

**RknRusty** Sun Aug 05, 2012 12:56 pm

I like it, it looks like it should be pretty aerobatic. That's a pretty BW too. I've never tried my Nelson/Galbreath head on mine, but I do use Bernie's drop in plugs with the 5 fin clamp. I think they are comparable to a Cox hi comp head. Mine seem to like 3 shims best for smooth running and dependable needling.

fit90 Sun Aug 05, 2012 5:42 pm

I went out to cut the grass and it started to rain so I played with some tank extenders instead. Damn the bad luck! I had two engines that had tank extenders on them . One was all aluminum and the other was an aluminum tank with a plastic extender. The alum/plastic combo was the one that did not leak. I just made sure the bolts were all the right length and everything was clean before assembly. I ran this engine (which is pretty much a Black Widow clone) on Sig 25% and an APC 6X3 and run times were around 2:30 + or - 10 seconds and it tached around 14.5K. I will give this a shot on the Stealth Sport and see if this increase in run time doesn't satisfy a little more. I will also try some different bolts and gasket sealer on the all aluminum set up and see what happens there. The grass is still uncut.

fit90 Sun Aug 05, 2012 5:53 pm

I just took the engine off the stand and shook it and found more fuel still in the tank. I have to take a look and see what's up.

fit90 Fri Aug 17, 2012 9:08 pm

After not getting the results I was hoping for with the Kavan tank extenders I just swapped the engine out with a Tee Dee .049 on a Norvel tank/mount. The engine run time is a whopping 1:15 now. However, after repairing it I put a keychain/fob camera on it so hopefully it will be an exciting 1:15 t watch.

Bob

andrew Sat Aug 18, 2012 9:23 am

fit90 wrote:The engine run time is a whopping 1:15 now.
Bob

Yeah, the standard NORVEL tank is a short runner, for sure. I've used it as a mount, but added an external tank for longer runtimes. NORVEL does make an extended tank mount, but it's pricey at $19.

finishing up old project Norvel10

fit90 Sat Aug 18, 2012 10:12 am

That would be a great idea but I have the battery and radio equipment up against the back of the firewall for balancing purposes. The radial mount Tee Dee that was the Engine of the Month two months ago was supposed to go on this plane but the fuel tank would have been too far back behind the radio equipment. I am going to keep playing with the Kavan tank moounts and see if I can put one together that makes me happy. If I can, that one will end up on this plane. So far I had one that ran for four minutes. I screwed it up during final assembly though.

Thanks for the tip,

Bob

fit90 Sat Aug 18, 2012 9:40 pm

couldn't keep the engine running more than a few seconds in flight

[youtube][/youtube]

fit90 Sat Aug 18, 2012 9:44 pm

Here's more

fit90 Sun Aug 19, 2012 12:49 am

a couple more short flights

[youtube][/youtube]

[youtube][/youtube]

fit90 Sun Aug 19, 2012 12:51 am

looks like I have a tank and engine that do not like to fly together. I might have to weigh my options.

**RknRusty** Sun Aug 19, 2012 1:05 am

I know that was irritating. Can you strap a little sack with a bladder in it along side the fuse or somewhere? It might look goofy, but it'll keep running and save re-balancing work if you just leave the empty Norvel tank in it.

fit90 Sun Aug 19, 2012 8:56 pm

Had a little time and went digging through some parts to try a couple of things for this little bird. First, I am trying an aluminun tank extender on an aluminum tank. I am using a small piese of thread between the tank parts as a seal. On many small full size airplane reciprocating engines the case halves are sealed with a piece of silk thread so I thought I would give it a go on this. Also, I found a tank mount for an MP Jet engine. It probably won't run any longer than the Black Widow did but it will have a lot more power. It will be interesting in the mean time.

Bob

fit90 Mon Aug 20, 2012 8:14 pm

I just changed the tank and engine. It is a Norvel tank/mount and Norvel Big Mig .061. On a Master Air Screw 6X3 cut down to 5X3 the engine ran like a scalded ape for about one minute and 30-40 seconds while I shook the plane violently. It gave good, consistent runs. I hope this is the answer. The flight time will be short but the flights will be fun. It is still butt ugly, though.

Bob

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