Guest of Honor in the Skunk Works

cribbs74 wrote:That plane still looks pretty darn good for being 36 yrs old!

Speaking of 36 yrs....that's a long hiatus for girls!!!!! Glad to hear the maiden was smooth and the plane is still in one piece. Never a dull moment at the Skunk Works Kim.

Yeah, girls had been on the scene a while before this, but there WERE other contributing factors...we all kind of scattered for a while. Bobby got himself married (to a girl named Sandy...they're still together with two sons), and I got a job with an airmail outfit, doing Gypsy Maintenance from a converted "Bread Truck" on Aero Commander 500's and Beech 18's that the company had scattered across the country.

When I was home, I was consumed with the building of an Easy Riser Ultralight, and a little brunette who took the rest of my time. I managed to survive flying the Riser, though the girls nearly got me several times, along with assorted other misadventures.

The Chipmunk never got it's turn, because when we came back to model airplanes a couple years later, radio control was the all rage, and so the control liners became Hangar Queens.

So now, she gets her time in the spotlight. The ancient silkspan is a lot like brittle spider web, and poor Wayne can barely handle the plane without punching a hole in it. I want it to hang in there for a mini airshow for him and his buds to showcase his building skills from "back in the day". Bobby can't turn with control line planes any more, so if it happens, it'll be me doing it.

I may have to re-retire to get all of this stuff done before I croak !

Hi Kim, is that a K&B Stallion .35? I assume the tank isn't readily accessible. I had a Stallion in a Bi-Slob which didn't work too well. The engine likes to run in a wet 2 stroke. I would certainly go for the Fox. I would just caution the considerable weight difference though. I see the Chip appears to have a Harry Higley aluminum heavy hub. Might just need a tad of nose weight in the event you switch to the Fox. They do fly well. That is one kit I wish Sig didn't drop from their line of control line kits. Ken

Any chance the K&B would perk up if you flipped it cylinder-up?

RknRusty wrote:Any chance the K&B would perk up if you flipped it cylinder-up?

I concur with the Rustmeister.
Even though conventional wisdom says it don't make any
Difference.
All my 'inverteds' have been awkward from time to time.
My YS 110'd Yak gets started 'wrong way up' every time.

Having the engine mounted upright or inverted shouldn't make any kind of difference. This probably wouldn't be possible to mount it upright as the tank would need to be removed and placed on top of the beams. The only time that will make a difference is when the engine is mounted on a profile. This is why a Fox.35 burps when mounted on a profile as the fuel is being thrown directly into the bypass which drowns the plug on a outside maneuver. There could be several problems . Is that the correct prop for that engine? It looks like a lot of pitch in the picture, I would recommend a Master Airscrew 10x5 or 10x6. The tank could've been sitting forever. There could very well be corrosion and crap inside which would suggest a inline fuel filter being constantly monitored until it's clear. The other is if that engine was on the plane for the set period of time that plane has sat, the plug is probably full of oil and gunk. The K&B demands a high castor oil content fuel of at least 25% (castor) and therefore a hot plug like a Thunderbolt r/c long or a K&B 1L would be a good choice to keep the fire lit. Also, in the event that engine has sat that long, a thorough clearing of the needle valve spray bar of old castor gunk would also be suggested. Those K&B engines aren't fearful of the nitro either. The Stallion and others Like the K&B 71 series had a two part crankshaft. The stud that holds the prop on screws into the shaft. It's always a good thing to make sure the stud is screwed in all the way in the event of a backfire it doesn't unscrew and puke all the parts all over. I've lost the drive washer from mine like that. Ken

Great stuff Ken but if the tank has been in there all these years I would say
it needs more radical treatment than an in line filter. I would get it out
even if it means cutting it out and thorough clean or replacement.
You have inspired this old duffer with your numerous posts to get his
Brodak Cardinal out the attic. John

Hello John, I agree 100%. I would try the easy stuff first though as these planes were built, you installed the tank within them so it's not just a matter of popping it out. Kim stated overheating. This can be caused by excessive lean runs caused by fuel starvation, incorrect prop, or vibrations which is foaming the fuel. Vibrations in the fuel can sometimes be cured by a shot of Armor All in the fuel consisting of 1-2 squirts in a gallon. A new plug would be my #1 starting place followed by a thorough cleaning of the spraybar. A iron piston engine is not going to start until it cools off. The engine becomes rapidly heat soaked and the compression doesn't return until it cools. Therefore the correct oil content is a must. I build all of my full bodied stunters now with accessible tanks. This is why I asked if the tank was accessible in my first post. I also pretty much know that Kim is already aware of this as I've already followed several posts. I have a tough old bugger at our flying field that suffers from a similar disease. He can get pretty rammy at times and I'm sure it's due to not being able to do what he once could. The patience level drops dramatically and the more he concentrates to stop the shaking hands the more it happens. I take his advice and try to help him when I can. He certainly can give you the wrong impression at first. My hat is off to you Kim for helping out and seeing the old bird back into the air. I sometimes have to take a deep breath and put myself in his shoes. In the event the tank is removable though this could certainly be a much simpler fix. The Chipmunk is certainly a plane worthy of doing a decent pattern. Ken

Hey Ken,

Yeah, you pretty much got the picture of where I'm at in your last post. There were so many variables that were out of my control, that I figured the only way to chase them down and get this pup running was to spirit it away to the shop.

My Uncle is a great guy, but never, EVER throws anything away...including fuel. If it sloshes around in the jug, he figures it must be OK ("That stuff costs MONEY, boy!"). The nitro and lube numbers/type are pretty much ignored with a "fuel is fuel" kind of attitude, and it's all stored in his super-heated backyard work shed. I still find myself in the position of a youngster in these dealings, and REALLY have to clamp up and keep my mouth shut in order not to look like a know-it-all punk.

This can be pretty tough as he tortures himself with relatively simple problems. I only recently convinced him that it's a pretty good idea to drain remaining fuel from a model's tank at the end of the day, rather than just let turn to milky syrup over the winter.

At this point, I've got the Stallion on my stand with a balanced M.A. 10-6 to see if I can get it run on my Sig 10%...I'm not sure WHAT we were running in it yesterday! The bearer spacing between the two engines is too wide for a simple hillbilly swap, so I want to see if the Stallion can be put back onto the Chip. I'm hoping for a miracle "Hey I like this stuff!" reaction from the Stallion to the Sig. If so, it'll be easier to persuade Wayne to use it, and I'll get him plenty of Sig 10%, to feed to it. I'll also sneak in a new glowplug to help things along.

When we first ran it, it was with an M.A. 9-6, and I thought the engine was gonna vibrate off the plane, so we went to 10-6. As you said, it's a good idea to bottom out that prop stud, and the thick prop hub (M.A. 10-6) caused us to dump the Goldberg spinner because I couldn't get enough threads out of the prop nut. I STILL needed something to guide the starter (I'd left my leather glove at home and wasn't about to add massive blood loss to my impending heat stroke!), so we swapped the regular prop nut for that monster Higley unit.

The engine has had a hard life, with every kind of hot-run any-fuel-will-do existence since our flying days back in the 60's.



The tank surgery is still on, though probably not tonight. Wayne couldn't remember the size or type he'd installed back in 75-76. I could easily see bubbles running to the engine as it ran (we had a filter on it that showed a clean screen after the run), but there was no way to tell if we actually topped it off, so it may be that the vibration was foaming what little we'd gotten in there.





Anyway, that's the deal at this point. I'd like to knock this project off quickly and get it into the air, but we'll see what happens.

Thanks to all you guys for your input. Cranky or not, this ole guy is special to me, and the last of my "Upper Tier" relatives. When he's gone, my brothers and I will be the leading edge of our family. Not really sure that I care for that...

Hey Kim, I knew you pretty much had it figured out. I think the Sig Champion 10% is a perfect choice.Running on high castor fuel has a healing affect on the engine. Maybe not initially, but it will build the compression back into that engine if it's tired or getting tired. The Stallion was pretty much a low cost engine at the time to compete with the red head Mccoys. If memory serves me correctly, my father purchased his in 1970 for around $9.00. That was about the time Mccoy came back offering the red head .29-.35's for $4.95. Everybody went for the Mccoy's and literally bought a new engine every few weeks. Some of those Mccoy's would be lucky to last that long. I actually have a few good ones that still are going strong. The K&B though had really good quality for an inexpensive engine. One thing is to keep the 3 head bolts tight that hold the cylinder to the case as you could launch the entire cylinder off of the engine. When you choke the Stallion for a prime, do you hear air leaking? I had problems with the black plastic restrictor in the venturi. I pulled it out and sealed it with sealer and reinstalled. I then placed fiber washers on each side of the spraybar where it touches the case. Any air leaks are certainly going to cause havoc. You have a great nostalgic combination there. In the event you want to retrofit the old Fox in there, you could make a aluminum plate and put it on top of the beams using the Fox's bolt pattern. I think though after some sorting out, your going to certainly get it corrected. I wish you success and keep those flying lines tight. Ken

shawn cook wrote: When you choke the Stallion for a prime, do you hear air leaking? I had problems with the black plastic restrictor in the venturi. I pulled it out and sealed it with sealer and reinstalled. I then placed fiber washers on each side of the spraybar where it touches the case. Any air leaks are certainly going to cause havoc. Ken

I didn't notice any at the time, but will have it up close and a bunch more handy running it on the stand. Do you know what the deal with the liner anyway? I'd assumed that it might have been to allow a common venturi to be used with a throttle assembly or spray bar.

Think I'll use the spraybay/seal tip. During our experiments yesterday, I slid a piece of silicone tubing over the needle/bar, hoping that might get the thing to settle down, so we'll do the seal also and see what happens...

Thanks Again !

Kim, I did see in your pic that you placed tubing over the needle. This is always a good practice and certainly doesn't hurt. It seems like you pretty aware of all the tricks. The engine was available in a r/c version as well. You probably correct as this plastic piece is just choking the venturi down to the proper size. I had a strap type muffler on mine and it didn't like that one bit as it retained waaay too much heat. I hope all works out as I know it can be quite rewarding to figure out all the little gremlins inside. Ken

Hey, Ken, good info on engines that a lot of us don't have experience with. I gave you a green + on your second post.

But, Damn, boy, can I sell you some paragraph breaks? Nevermind, I have some used ones I can send you for free. Just kidding... humor argh argh (Mork). I figure we've been acquainted long enough to where you won't be offended by this. Sincerely hope not, anyway. But your daunting brick walls of text make my head hurt.

[/hijack]
Carry on.

A little off point now, I spent the day driving a government bread truck across oklahoma and Texas and was going to reply earlier.

I may have to re-retire to get all of this stuff done before I croak !

That statement is something I only recently realized. I am no longer buying cars and motorcycles for that very reason. Cox engines? Oh yeah, they don't take up much room. And to refurb one of em takes all of a day.

Those Higley hubs.......I had no idea they were to be used to correct CG issues. I just thought they were a robust hub.

Rusty, no offense taken. You had me laughing actually. Trust me, I need that as I have been in quite a lull. I've spent the past 9 weeks sitting here going out of my mind due to shoulder surgery. My week consists of physical therapy 3-4 times a week and just coming home to sit in a chair. Please take my apology as I don't mean to ramble. This hobby is what I enjoy the most and not being able to even open a fuel can in a timely manner makes it that much more difficult. I spent 7 of the weeks in a sling which more or less makes you a couch potato. I'll keep it short from now on. Ken

shawn cook wrote: Rusty, no offense taken. You had me laughing actually. Trust me, I need that as I have been in quite a lull. I've spent the past 9 weeks sitting here going out of my mind due to shoulder surgery. My week consists of physical therapy 3-4 times a week and just coming home to sit in a chair. Please take my apology as I don't mean to ramble. This hobby is what I enjoy the most and not being able to even open a fuel can in a timely manner makes it that much more difficult. I spent 7 of the weeks in a sling which more or less makes you a couch potato. I'll keep it short from now on. Ken

Hey Ken...not to speak for Rusty, but I think his comment was geared toward you putting paragraph breaks in your posts, not the length of the post.

Please don't back off posting the good stuff !!!!

Kim wrote:

shawn cook wrote: Rusty, no offense taken. You had me laughing actually. Trust me, I need that as I have been in quite a lull. I've spent the past 9 weeks sitting here going out of my mind due to shoulder surgery. My week consists of physical therapy 3-4 times a week and just coming home to sit in a chair. Please take my apology as I don't mean to ramble. This hobby is what I enjoy the most and not being able to even open a fuel can in a timely manner makes it that much more difficult. I spent 7 of the weeks in a sling which more or less makes you a couch potato. I'll keep it short from now on. Ken

Hey Ken...not to speak for Rusty, but I think his comment was geared toward you putting paragraph breaks in your posts, not the length of the post.

Please don't back off posting the good stuff !!!!

Absolutely, let the information flow freely, the more the better. It just can be confusing when you realize the article has taken a tangent and you have to back up to re-read so everything falls into place. It takes a lot less energy to read an article that is broken into sub-topics with breaks between paragraphs. I like what you write, keep it coming. If you don't want to bother with breaks, that's fine too, I'll keep reading.

Hello Ron, that hub is also available in brass which is much heavier. One thing I've found especially when using a Fox.35 mounted on a profile is the amount of vibration it can suffer. I've seen the brass hub used and it tamed that sort of problem. I imagine it just takes the harmonics out of the engine run side to side.

Typically most commercially available kits build nose heavy therefore the hub isn't needed. In the case of the Brodak P-40 ARF and the Horizon ARF PT-19, these are two examples that are both real tail heavy which both could use the brass hub even with modern heavier case engines. Generally, most people don't find this out until the plane is splattered. I've watched it happen more than once.

Just as a side note, most spinners really add a lot of nose weight to a plane as well. This is really the case using the aluminum spinners. A plastic spinner is considerably lighter. In the case of the P-40 a nice metal spinner not only looks cool but also places your cg correct. In the case of the PT-19, the Higley unit even looks like the real thing. Ken

Got the Ole Stallion running just now. With a new glowplug and M.A. 10/6, it happily ran on both Sig 10% and Glowplugboy's 10%x20%. A good 4-stroke break put the RPM's in the high 9's, and I even managed to stay out of the prop getting it there!

With both fuels, I just let it run out the test stand's 4 ounce tank, and it hungrily emptied it both times.

Now, guess it's Exacto time....lookout Chip !!!!





As often happens with these old dogs, in the midst of taking pictures and waving the tach around, it's un-muffled bark gave me a momentary flashback to the days when a "Super Ringmaster" really was "Super". Wayne would release the dark-red plane, as I braced against it's pull on the lines. After raising a rooster tail of infield dirt on takeoff, the Ringmaster would immediately be put through it's paces, rarely remaining upright or level for more than a second during the next 3-4 minutes.

Good stuff....

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Edit: Moved here after posting it in the wrong thread.



The Chip is Up, and Ready to Rock !!!!
Kim June 8, 2012 at 11:33 am

Had a dress rehearsal for Wayne's Sig Chipmunk this morning !

Vibration with the K&B Stallion is dramatically reduced from our run a few weeks ago (probably due in large part to balancing the prop), and it ran out it's fuel. The filter showed totally clean, and other than the Williams Brothers Pilot Head bouncing around inside tthe canopy, she's looking first-rate.

There WILL be video with this one !

Very cool Kim!

Good go, Kim. Always nice to see the old standbys brought back to life.