[79FT]: Building Things
...or was it pickles?
|On:||May 17, 2019|
|In:||[Chickenhouse Charger] 2019 Annual|
|Tags:||6781G, MA5 Charger, Annual, engine, Rotec TBI, prop|
So after having discovered the electrical mess, I realized that she's gonna be sitting for a while.
Pickle time! Damn, this pickling thing is becoming a thing, excuse my tautologies...
I had to put her together enough to be able to run the engine to circulate and warm up pickling oil.
And she was apart. With intakes off, TBI almost off, no oil, and such.
So first, it was to be intakes.
RTV where there should be none
Somebody put RTV to "seal" the intake gasket. Oh well.
Did you know that those 1 1/2 inch rubber hoses that go on intake tubes are much easier with very thin coat of oil?
Oiling the hoses
And then, it was the TBI.
Recall that when I was putting her apart, I found pipe dope on the TBI inlet port?
Let me explain.
Fuel goes into gascolator. Then it branches: one branch goes to the engine driven pump, the other goes to the electric pump. Then, they go to the regulator on the TBI. Then, a couple of 90 degree fittings feed it into the TBI's inlet port, which has the "last chance" screen in it.
That's the port here, right above the airflow straightener:
TBI from the down low
See that white gunk? That's Teflon dope. "Aircraft grade"; whatever.
Here's the problem.
TBI inlet hole
Fuel has to go there, into that inlet hole. That's what the screen fitting screws into. Right past that, inside the TBI itself, there's a turn, another turn, and a spray bar that sprays gas into the intake, injection-style, thru a tube with a bunch of tiny holes. That's why there are screens in the fuel system: to prevent gunk from clogging up those tiny holes.
So now, what happens when you take a male fitting out of a female threaded hole, and the fitting was doped? Some of that stuff ends up on the female portion. Next time the fitting is put in, dope remnants will be pushed in past the engaged threads, and possibly clog up the works.
Not. Good. At. All.
That's why there is the copper crush gasket behind that screen fitting - to seal it to the TBI body w/o requiring anything extra. You can kinda see that gasket all smudged around with that dope on the first picture.
So I had to deal with it.. Clean it out somehow.
It was crumbly, but sticky enough to not want to come out.
I tried every solvent on hand. Nope.
I tried carefully scraping it out with a dental probe. Yeah, kinda worked, but I wasn't satisfied.
I tried every solvent in my buddy Dick's hangar. Nope.
In desperation, I drove to the local Home.. strike that, Aerospace, Depot, thinking about picking up every kind of solvent they had and I didn't.
And then, I remembered this:
I don't know what kind of concoction that is; but it worked! The hole was clean. Next time was a couple days after, and when I got back to the hangar, I discovered that it has turned into a lake :(
Lake in my hangar
Grading's all screwed up around our hangars, and when we get lots and lots of rain, they flood. Not too much though, luckily. This was the second time in the past few weeks - first time, I had my tools scattered around the floor. This time, I was smarter...
Anyway, back to the TBI. The rest of it went together quite nicely. I discovered that there was TorqueSeal put on the idle mixture screw.
Why? No idea. That screw is spring loaded. Should stay put.
Torque Seal where there should be none
I wanted to flush the lines and then the TBI to make absolutely sure none of that dope went it. The best way to do that would be with the electrical pump; but I'm a one man show.... and the switch for it is 5 feet away from the firewall.
So, I had to rig me up a little doodad.
The simple click switch
.. with ring terminals
The ring terminals were hooked up to the Master Solenoid in such a way that when the button was clicked on, the Solenoid would close.
The pump was turned on.
This way, I could click my button, Master Solenoid would close, and the pump would start running. Neat-o! I'll need it later, too.
Flushing - braided hose provides nice bond to the airframe
I borescoped the engine (looked alright - I'll post a report about this later, maybe...); and it was time to fill'er up with oil.
Pickling oil was mixed up next, and into the engine it went.
A pitcher of pickling oil
A recipe for a mess...
After filling the sump up, it was time to check for oil pressure. Lycoming tells you in SB1241C to pre-oil your engine by cranking with the starter in 10-30 second bursts until oil pressure comes up to 20 PSI.
Well, oil pressure gauge on the Charger is finicky, so I wanted it to at least move.
Oh wait. She has an ignition/start switch. No way I can use that to crank and not have a hot mag w/o messing with P-Leads.
Also, I might want to crank from around the firewall (the prop was still off).
But I had my pushbutton doodad!
So I rigged it up to the starter solenoid this time.
Of course I misunderstood the way the starter solenoid was wired.
It had two terminals.
I thought one of them was ground; with the wire going to the firewall. The other then was supposed to be positive.
That didn't work.
I measured it - between those terminals - nothing. "Dead starter solenoid", I though. Crap! It was 8pm. Auto parts stores were closing soon.
I rushed to a nearby O'Reilly. Picked up a starter solenoid. Went back.
Measured it too. NOTHING? How come? Something was amiss.
Only then I started suspecting that something was off. That other terminal on the original starter solenoid I was hooking my positive wire to was all corroded and looked like it never had a nut.
OH! The way it's supposed to be wired is that positive goes to the same terminal where that wire I thought to have been ground was. It wasn't a ground wire - it was a diode. And the ground was off of the case of the solenoid.
So, we're cranking now.
30 seconds. No pressure. 30 more. No pressure. Crap!
I unhooked the oil pressure sending hose (the one that hooks up to the line that goes to the gauge).
Crank. No oil. A couple bubbles is all I got.
The oil pump de-primed itself?
Kinda makes sense I guess? The plane was sitting for way too long :(
So, I took off the oil cooler return line. Dumped another quart of oil in there.
I had this hose fitting that goes on top of an oil bottle that was very neatly set up to mate with the engine oil hose's flare: so I could squeeze the bottle and push the oil in.
After the whole quart, I re-hooked the line back onto the oil cooler, and tried again.
Success! Now, I saw oil coming out of the oil pressure sending hose.
Hooked it up to the gauge line, and saw the gauge move, finally. Good.
Damn, with all that cranking I ran out my old battery I had put in there.
Now, have to flip the battery (to put in the good one - the flying one - I always use my old battery from the Cheetah when I mess with electrical, not to abuse the actual "production" battery).
Now, the top spark plugs go back in, the ignition wires get hooked up.
Bolt one - start it in. Bolt two. Bolt three.
Bolt 4. Doesn't go in? Not even a chance? What the hell?
I pulled the prop back off and laid it down. Put the front crush plate on top (that one positions the bolts).
No matter what I did, there'd be at least 3 out of 6 bolts that won't go in. This time, it was a few dry days, and I guess the prop moved enough to have the "top" and "bottom" holes (if looking at the prop horizontally) move closer together. It was off by almost a 1/16th.
So here I was. With an engine that was cranked for a total of a few minutes, and probably had scraped a lot of oil off of cam lobes and lifters.
With a prop.
I couldn't put on.
Which I needed.
To fire the damn thing up.
It was late. I tidied up, and went home.
I wrote a note to Frank Johnson who made the prop that same night, and called him the next day.
He wasn't surprised. "Redrill" is a simple fix.
But I was a bit apprehensive, and this was a nice excuse to meet him. He's 2 hours away from me. We agreed to meet in a few days, at the first time he was available.
So, the engine with oil scraped off the lobes had to sit for another couple days.
Nothing I could do in that short a time...
The weekend hit us; and it is a weekend in May, in Texas. Which means...
The annual fit inspection
Into the trailer the prop went, and to Frank's we drove.
All tucked in
Of course, it took us 15 minutes out of 3 hours I spent there to fix it. The rest of it? Well, what can two guys who're crazy about airplanes do at one of those guys' shop and hangar? Hmm... What could we do? :)
The weather was swell, and I was in a good mood - and airport was on the way back from Frank's.
So, I went straight to the airport.
The prop went on beautifully.
It was nice, sitting in a running, shivering airplane, to watch the sunset. If you looked up, it almost felt like flying. With the buzz, the shake, the smell and the noise.
A couple days later, I went back to the hangar, sprayed the engine top and replaced spark plugs with desiccant.
Now, I can focus on the electrical mess...
The Muffler plug
The future in aviation is the next 30 seconds. Long term planning is an hour and a half.
Russian autumn tradition
|On:||Oct 07, 2014|
No posts for 1 month and 5 days! Holy cow.
That's all been eaten up by a couple projects. One of them ended up being a complete redraw of all airfoil sections on the lower wings on the Skybolt; and nothing to write about (no pretty pictures, very routine work). Just lots and lots of cleanup.
Another one... was me following an old Russian tradition.
You see, during long winter months Russians' desire for fruit and vegetables (and mushrooms) is satisfied with pickled everything. Cucumbers, tomatoes, cabbage, grape leaves, dill (!), apples, garlic, fish (haha :) ), and other things which I don't know English words for.
My genes are calling. It's fall, and I had to pickle me something.
It was.. a disassembled Lycoming for the Skybolt!
Some weeks ago, a gentleman posted on the Forum about him selling an O-360-A4M, all overhauled, yellowtagged, and such, by Superior; with higher compression pistons from ECI, with everything needed to put it together minus the sump and accessories, for a very attractive price.
Best part was, it was disassembled, so I am to get all the fun putting it together without the disassembling and sending parts out for overhaul (and well, paying for that too :)).
In short, it was a great deal.
The problem? Well, I will not need it for quite a while. 10 years maybe, if I go with the speed I'm currently going at.
I figured, assembling and pickling it after would be a bad proposition. A much better one would be to pickle it part by part.
As usual, started with a thread on the Biplane Forum.
At the end of the day, I ended up using three things.
Phillips 20W-50 Anti-Rust Pickling Oil
Good' Ol' STP
Cortec CorrShield VpCI-368
This latter substance is amazing. It's mineral spirits soluble, moisture displacing spray-on stuff that can protect up to 2 years in outside (!!!) storage. I'm storing the engine parts inside my house, so I figured it will do very good for a much bigger number of years.
It sprays on, and then dries over a couple days to consistency of candlewax. A bit sticky, but very tough. They claim it's scratch resistant.
Just in case I missed something or ended up scratching it off; I decided to also put a thick layer of Aeroshell grease on everything that's covered with CorrShield. Just in case.
It showed up!
For smaller pieces, I first wanted to put them in sealed sandwich bags, with some STP / Oil 50-50 mix, and squeeze all the air out.
New connecting rod
Now in the baggie with STP/Oil Mix
Gears and bits
.. all bagged up
But after them sitting like that for a couple days, I didn't like how all the oil drained to the bottom of the baggies. So instead, I submerged everything in 2 oil/STP baths.
Piston pins, gears, rocker arms, misc accessory case things in oil/STP bath
Pushrods, piston rings, tappets, etc in oil/STP bath
At this point, I ran out of oil and STP... And I had too much of CorrShield and grease -- and, after playing for some time with CorrShield and seeing how tough it is, I decided to use it on everything that didn't get into oil baths; even on smaller parts.
One of the jugs
Jugs, right side up and tops CorrShielded and greased.
Some more small pieces stored "dry", covered in CorrShield and grease.
Thru studs and pushrod tubes
Bearings, oil pump housing and minor pieces
This project took a couple weeks worth of evenings; and now my inner Russian is completely satisfied with his stash of pickles!
"Approach, what's our sequence?"
"Calling for the sequence I missed your callsign, but if I find out what it is, you're last."
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This website only shows how I did things in my various projects. These pages are for information and personal entertainment only and not to be construed as the only way, or even the perceived correct way of doing things. You are responsible for your own safety and techniques.