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Another year flying at Fort Jax is in the books!... or maybe it's next week

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Another year flying at Fort Jax is in the books!... or maybe it's next week

Post  RknRusty on Sun Dec 20, 2015 7:30 pm

I wasn't sure if I'd make it to the field today. Had to get a lot of Christmas stuff done on Saturday to free up some flying time. It was chilly this morning  but I had a stickyback Hothands body warmer stuck to the chest of my T-shirt and lots of clothes, so I was toasty. I did pack the Ronsonol in the flight box. A few props to try were in the plan.

Bob woke up with the green death, so it was just Wayne and Me. He was late, so I didn't expect to have time to do any more than test the prop that was on the Cardinal. It was a pretty day with a breese, mostly coming from the southeast, so our patterns were with the sun at our back and side. I had an MA 11x5 because I wanted a straight 2-stroke run. I sure like to see a smoke trail, but the first flight was a pleasant too-rich mid-5 second flight with the best landing I have ever done... right after the first loop of the V8.

After that I got a couple of good runs at different settings, and finally settled on a good 5.2 second run, finishing at 4.8 which is fine with me, especially for windy days. Good cutoff and damn, greased another landing. Then I flew one more without touching the needle. I had that feeling, walking toward the handle, should I turn around and tweak it... nah. A screaming lean run that lasted somteen minutes. I could hear crackling preignition the whole time. And 3 bounced the landing Lol. The engine wasn't as hot as I feared. It had light smoke in the exhaust, so that's good. But the goo was mostly gray, so that's bad. It's Will's engine too, even badder if I roasted it. I'm not expecting any damage, OS are tough engines. Ask me how I know.

I don't know much about OS LA engines, I need to kook them up. Are they all ABC/N?

So anyway, Wayne brought his Primary Force. A super cool plane, sort of reminds me of an Intruder in front, and I don't know what in back. Definitely on my gotta have someday list. He chased the needle on his LA25 some too, using a 9x4 APC. But that little engine is a badass machine on his 35 ounce plane. He built it from plans after Mike Pratt left Sig and drew up plans for it. It looks pretty fun to fly.

I took the Oriental and the Shoestring. I'd added head gaskets to the Oriental and haven't tried it yet. . I'd have had to fool with adjusting a handle, so I blew it off. I need more of the Tom Morris handles so I don't have to play switcharoo. Bob has the venturi for the Shoestring, so it sat idle too. Wayne is urging me to try a 12x4 APC on the Cardinal, so I'll see if it makes my .46 more manageable. Bye the way, I wish I'd had a Cardinal a long time ago. This is a good flying plane. Mine weighs about 50 oz. I don't know how that stacks up against other Brodak Cardinal kits. It's obviously not too heavy. It has a perfect good hard pull for me, and stays tight. And it's stable, my pullouts are getting much better... shape, not altitude. I quit trying to force low bottoms. I'll have to let that be part of learning everything else. I am not a natural at this. I still belong in Intermediate. I hope some time I can break out, I see some spotty improvement here and there. Just keep on chooglin'

We got more flights today than usual. As my observant flying buddy likes to say, We got the good out of the day. And so we did.
Until next time, hope you have fair weather and a Merry Christmas, or your chosen celebration
Rusty

The P-Force


This is me falling down laughing. But at least you can see the Oriental Dragon I stuck on the nose.



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Re: Another year flying at Fort Jax is in the books!... or maybe it's next week

Post  Ken Cook on Sun Dec 20, 2015 8:00 pm

The LA engines are ABN. I can't explain the grey goo. It shouldn't be present even if you had a lean run. Essentially if the run is too lean, the engine should sag and lose compression and return when cool. Not a big deal really. If your getting gray oil, I would take a closer look at your aluminum clamp mount as vibrations could be contributing to the gray oil which is associated with aluminum. A loose muffler will do the same. Your exhaust should be clear. A needle valve body loose in the venturi will do the same bleeding gray oil down the side of the engine. 50 oz's sounds a bit heavy. I recall many in the 44-45 oz range. That being said, I flew them with a B-40 which is also a 7 oz engine. There would be almost 3 more ounces with the LA .46. I have a plane here that has it's hinge lines taped with Scotch Crystal clear tape. This seemed to help my porky stunters and I'm wondering if your Cardinal would benefit equally. I was having the plane somewhat fall down in the overhead maneuvers and this certainly helped.
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Re: Another year flying at Fort Jax is in the books!... or maybe it's next week

Post  RknRusty on Sun Dec 20, 2015 10:43 pm

Yes, the mount and muffler would have been what first popped into mind too. Earlier I had a run where something was rattling(but clear exhaust at this time). All was tight enough, but I suspected both. I put an extra half turn to the engine bolts, and of course had to R&R the muffler, it was tight. I removed a fishing line slide clip(stooge hook) from the tail wheel and the noise seemed to go away. It was two flights later that I had my lean run with the preignition and gray goo. The planes are still in the car and will stay there until tomorrow when I'll give it a thorough post flight inspection, re-checking the mount, and I'll look at the NV, thanks for that tip.

I'll mount a 12x4 flat-tipped Zinger until I can get an APC. I tried a 12.25" APC last week and it was pretty good, but ran out of gas at the clover. Leaner would have solved that. Do most people run steady 2-stroke with these engines? I kind of like it that way, just need to find the right prop. I bought a fistful of 11x5 and 11x6 MA props, just knowing one of them would work. And it did for one of my flights. I tached my launch at 10x4 on that flight. Should have tached it again the next flight, but wrongly trusted it to stay the same.

My hinge lines are all sealed with clear Scotch tape. So are many seams on the Monokote. This is not ARF 'kote, so it was either a kit or an ARC. I'll ask Watt. He usually doesn't build ARFs. He can build kits extremely quickly. They always need detail checking, but his woodwork is usually outstanding.
Rusty

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Re: Another year flying at Fort Jax is in the books!... or maybe it's next week

Post  Ken Cook on Mon Dec 21, 2015 4:17 am

Rusty, for the most part the answer to your question is yes. The engine wants to run in a fairly steady 2 cycle. Pick the nose up and listen for the transition. If the engine doesn't have it when you point the nose up, needle it until you do. I personally feel the engine is more comfortable (needle friendly) using the 11" props. I would not use any prop over a 5 pitch. The reason the 12" prop works is the pitch is so light. The 12.75 x 3.75 is really too large and should be clipped a bit to get the rpm's up. It will work but it can also overheat if used in a cowled engine. Larger props can also cause needle sensitivity. If your using the remote needle, the engine is certainly crying out for a better option. Check the backplate screws for snugness. If the screws came loose, it can lead to unwanted performance and the gray oil as well. Do you know the venturi size? This is important and it could explain a lot of the why and why not which your asking. Many switched the venturi to the smaller LA .25 size. OS also was not very consistent in what they sent new in the box. If you have a .265 power will be slightly down but economy will be much higher.

                   Just to set the record correct, the larger prop should've yielded you greater economy. This is essentially due to slowing the rpm's down. If you used the larger prop and the flight was short, it was due to the engine running too rich. The larger prop probably wouldn't want to turn up real fast due to the load. This is why I prefer the 11" variants. The larger prop may start out sounding ok initially but by the time you start entering the squares, the engine quickly starts to sag due to engine loading. It's always better to run the engine faster than to lug it.

                Is that the stock muffler on that engine? Is the cone still inside that muffler? Open the front door and heave that as hard as you can. Take the tongue muffler from your Oriental and bolt it onto the LA it fits. Try and refly and get back to us. The tongue muffler doesn't mask the engine sound and makes it very easy to set the needle as it will cackle loudly when you point the nose up. The POS stock muffler doesn't do that. It's too heavy and the BS about it acting like a tuned pipe is all BS equally. The harder you run the engine the less restrictive the exhaust needs to be. The gray oil could also be coming from the internals of that muffler. They use a through bolt that passes through the cone. It vibrates and gray crap comes out as well.  Ken
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Re: Another year flying at Fort Jax is in the books!... or maybe it's next week

Post  RknRusty on Mon Dec 21, 2015 11:21 pm

Thanks for the reply Ken. I also think the 11x5 is going to be my prop of choice. I got a perfect run with it and only I was to blame for that lean flight, for not turning back to richen it up before taking the handle. However this engine has been passed around to so many planes and people who flew it with a 12x4, that I'm under peer pressure to try it. So I will.
On the runs I liked with the 11x5, it got 10 laps after the Clover on 4.5 oz. of gas. When it was running lean, I listened for sag and it didn't. Maybe it was not as lean as I thought. What sounded like pre-ignition might have been something rattling, it's possible to make that mistake.

I've been flying it with a hollow OS 762 muffler, a small one that had the stinger pointing straight back and it doesn't have a through-bolt. The two halves screw together, or are pressed, there may be two variations. But I ground the stinger off and opened the hole to  about 3/8". And I just realized you're right, the .35 and .40fp have the same muffler size and I have a tongue muffler in my flight box from the Nobler's .35. I had it in my head that it didn't fit, so I never tried Duh! I'll bolt it on. I measured the venturi and I think it's the big one, but my notes are in the shop. I am pretty sure it's bigger than .265".

Here's a pic of the small #762:

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