Sunday, February 22, 2015

48-04 Muffler

Well, this took some grunting, but no real problems to install. Nick helped hold things in place to get the initial fitting of the 4-legged beast, then it was just a matter of connecting the springs.  As mentioned, I used 8” tie wraps as pulls to manipulate the springs without using a metal tool. 

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Close up of tie-wraps as spring manipulation tools




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48-02 & 48-03 Exhaust Tubes

I had so much fun that I couldn’t stop with over an hour left before I had to get ready for work, so I dived right into the exhaust system.  These two pages have the same instruction repeated four times: once for each cylinder.  I took the precaution of labeling each exhaust tube before removing it from the muffler.  Good thing I did, ‘cause I was dumb enough to not pay attention and was successful at installing tube #1 on cylinder #4!

The tubes are held to the muffler with very strong springs.  I recall briefly reading that springs must be handled with care and to avoid using metal tools on them to prevent scratches -> stress risers -> cracks -> failures.   I hit upon the idea of using 8” tie wraps because they are soft plastic that is quite strong.  It worked well, and you’ll see a picture later on with a couple still in place since I will have to remove them in a few pages.


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Port Exhaust Tubes


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Starboard Exhaust Tubes

46-20 Oil Fitting replacement

The Rotax comes with a banjo bolt & hose nipple style drain for the oil/foam effluent from the engine.  The Book calls for it to be removed and replaced with a straight nipple instead.  I didn’t make too much of a mess with the ~ pint of oil that was waiting to come out of the hole while I tried to change things.  I also didn’t realize that I could re-use the yellow cap until most of the mess was already made.  Lastly, I don’t have a deep 3/4” socket.  I torqued it using my fish scale and known-length wrench.

Oh, by the way;  this completes the chapter on engine installation.  On to the accessories!


IMG 4074

Straight Nipple oil discharge

46-18 Fuel Pump Drain Line

Conceptually simple, moderately challenging to install.  In the picture, you can see a small metal tube starting near the upper right and snaking down and then to the left.  It transitions to the black tube tie-wrapped to the orange fuel line, thence to terminate below the bottom of the firewall.  This is the line that vents excess fuel from the pump.  I’m not sure why it’s not just a long length of the black hose, but I bet that heat from the cylinders has something to do with it it.  The hardest parts were bending the aluminum tubing and then attaching them with the dual cushion clamp trick.  Bending the tube was not as fear inspiring as it had been previously.  I misjudged where to put the 1st bend.  Rather than trying to straighten it out and then rebend in a better spot, I corrected by adding a bend to divert it away from the oil pressure sensor, then made a sharper bend to get back on track.  I was fairly pleased with the way that I didn’t get upset.

Holding two cushion clamps together with enough force to get a bolt & nut started is another challenge.  The Book called for using safety wire but then inconveniently states that that technique is not shown.  I used a needle nosed vise grip to hold the flanges of the cushion clamps together, then used an awl to forcibly line up the holes in which I could insert the screw and bolt it all together.  I did remember to go back and trim those tie wraps after the picture was taken.


IMG 4072

Fuel Pump Drain Line

Saturday, February 21, 2015

46-17 Manifold Pressure line

Conceptually simple.  Simple to install.  Just a plain hose that goes from the compensator tube (allows equalization between the carbs) and the manifold pressure sensor.  It doesn’t even need a clamp on either end!


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46-16 Starter Motor wiring

Conceptually simple, challenging dexterity.  In the background you can make out a booted white cable heading down and to the left.  That’s the 12V from the starter relay to the starter motor.  In the foreground is the ground from the starter to the airframe/battery.  Please note that this is the best possible view I could arrange with my camera.  Think about trying to squeeze my fat fingers and tools into that space.  Miracle, eh?

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Starter Motor Wiring

46-15 Regulator cable routing

The instructions show a lot more excess length than I have to work with.  It says to make a service loop to take up slack, but I’ll work out something else when all of the other wiring is complete.


IMG 4065

Regulator Cable forward of the firewall

46-22 Regulator

The regulator had previously been located on the shelf inside the engine compartment where it suffered a high failure rate, presumably due to excessive temperatures.   Apparently, they are in the discharge of heat from the radiator and also have direct line-of-site to the #3 exhaust tube.  I had previously documented putting in the nut plates to accept the regulator (see 46-23 on Jan 18), but today was the actual installation of the regulator itself.  For a while, I thought I should have skipped the nut plates and gone with the nut & bolt approach.  It was amazingly difficult to start the AN3-5 bolts into the nut plates!  The positioning is awkward, with the regulator underneath the glovebox.   It took multiple attempts to get the nuts started, but it finally aligned (or was it the stars that aligned?...) and it was installed.

The next step was to take the various wires and put them into the connector that goes to the regulator.  I double checked everything, then placed it at the regulator.  The photo below was a “blind” photo so I could verify that everything was where it was supposed to be before I attached the connector.  


IMG 4062

Regulator and it’s connector, prior to engagement 

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Here’s the view from the copilot’s lap.  The regulator is hanging from the ‘roof’ in the picture, and you can see it reflected.  The big yellow lines are the generator output; you can’t see the white DC outputs; and the thin yellow line is something else I can’t remember.   Note the nice bubble in the brake line that still needs to be bleed out.


46-21 Firewall penetration grommet

I predicted this page based on two prior episodes of making fire wall penetrations. This is Van’s traditional approach of using a grommet of appropriate OD and having me ‘punch’ out the center using a 1/2” socket.  The metal braided cable is the shielded generator output on its way to the (newly relocated) regulator.

This grommet will also pass the 3 cables that control the engine: throttle, choke & heat shroud.


IMG 4060

Center Firewall Penetration

46-14 Thermocouple wiring

There are 3 nice brass nipples that get snap-on connectors that transmit temperatures.  They are on the #1, #4 cylinder heads and just at the oil filter.  You can see wires on two of them.

IMG 4058

Temp sensor wires on oil gallery & #1 cylinder

Friday, February 20, 2015

46-09 Drip Pans; Clamp Block

Well, I had to wait for a $10 jar of fuel tank sealant to arrive so I could appropriately seal the drip pans.  (Technically, that’s step # 11 from p 46-08).  The instructions also call for a 1/4” blob of sealant to go under the carburetors, which get a bit of Beolube to allow disassemble later.  When I put it all together, I’m a bit bent out of shape to discover that the carb is no where near the blob at the bottom.  I have no idea why this step was included.


IMG 4053

Left Carb w/ Drip Pan


IMG 4054

Right Carb with Drip Pan; Fuel Block Assemby

I had done the work with the fuel block several days ago, but didn’t publish until the rest of the page was done (yesterday).  The only real problem was getting the pilot jet out of the upper banjo bolt.  The Book cleverly states “Remove the pilot jet from the banjo bolt M8x1x17.  It will not be replaced, but keep it in a safe place.”  Well, it’s not being kept in a safe place.  The damn thing needed to be drilled out and backed out with a removal tool.  I sure hope that I don’t come across “using the pilot jet preserved from page 46-09...."

46-13 Easy Start Wires

There’s no picture here because these wires are totally invisible.  "Why are they invisible?” you might be asking yourself.  Because they are small and completely hidden from view.  They are also nearly impossible to coerce into the bottom sides of the lower connectors coming out of the electronics modules.  I needed son Nick, with his pre-adolescent hands, to actually get the pins started into the connectors.

46-12 Ignition wires

This was embarrassing.  The Ignition Harness is the white pair of wires that you see in the picture.  I found those in my bin of parts without much problem.  It has a connector on one end.  I spent several hours over 2 days scouring my parts bins trying to find the mating connector (neither are pictured) before I finally realized that they had thoughtfully mated the empty female connect to the male on the harness.  Once I figured that out, it was half solved.  You see, the other half of the problem was that I couldn’t find the wires that were to go into the newly located female connector.

IMG 4049

Ignition wires in A1 and B1

In the picture below, you see me puzzling over the only two candidate wires that I could find.  I’m looking for wires that are Blue and White/Blue according to The Book.  Unfortunately, there aren’t any blue and white/blue wires coming out of the firewall.  I identified all of the other wires and had just these two left over.  There were no good labels, either.  You can’t make it out on this picture, but blown up on my phone I could make out 3 digits.  Nope, they didn’t match anything in The Book either.   

I had the bright idea of seeing if the pins appeared to be appropriate to mate with the pins in the aforementioned socket.  I tugged a bit to try to do a test fit and to my embarrassment the two short unlabeled wires easily extended about 5 “ and were found to be labeled J152 and J153, just like The Book said.  I’ve learned that colors are not always what The Book says, especially when an explicit label (such as these) can be found.  

After that, it was just the usual creative cussing to finesse things together in cramped quarters.


IMG 4047Candidate wires to be designated J152 and J153

Tuesday, February 17, 2015

12-03 & 12-04, install V-stab fairing

There’s the final step of the vertical stabilizer assembly:  the fairing was nearly perfect when I put it up there and only required 2 or 3 passes with 80 grit paper to get a nice final fit around the front of the rudder fairing.  I slid a folded piece of paper between the two fairings to verify no-contact at the extremes of rudder travel.  To my surprise there was no binding, and no gap either. :-)


IMG 4041

Faired & Installed  V-stab & Rudder 

By the way, in case you’re wondering, “yes” my garage ceiling has mange.  As near as I can tell, the surface was’t prepped properly when the treatment was applied.  Chunks of thin white plaster randomly rain down on whatever is stored in the garage for any length of time.  Another reason for putting sheets over the plane!

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Draped Sculptures of Airplane

11-10 V-stab forward fairing (the Nose)

Really?  An entire page to tell me to put the nose on the v-stab?  OK, I’ll post it.

IMG 4038

Forward Skin on V-stab

11-02 Install V-stab & Rudder

Another big change for the eye—the fuselage has its first tail feather installed.  Putting on the v-stab wasn’t too bad, just some bolts and screws.  Hanging the rudder could have been easy, if I just wanted a temporary installation so I could trim up the fairings, but no, that’s not my style.  I probably spent an hour trying to align the various washers while threading a bolt through the various pieces.  There’s a pretty good chance I’ll have to remove the rudder, but now I can document that I finished page 11-02, even if I have to remove the rudder in the future.

IMG 4036

V-Stab & Rudder installed

By the way, if you are wondering why the top looks weird, it’s because I have already riveted the rudder fairing in place.  The Book says to install the rudder prior to finishing the stab fairing, then to remove the rudder and rivet on its fairing.  (You can’t rivet it in place as there’s a rivet on the front and you probably can’t get a rivet puller in there.) As mentioned above, I’d like to leave this on until it gets painted.

12-02 V-stab & Rudder Fairings

I dilly-dallied for nearly 2 years before tackling the finishing steps of the vertical pieces because I had never worked with fiberglass before and I was afraid to start.  After sanding the engine cooling shroud, I realized that I had crossed a barrier and so went way back to the empennage to do a little catch up work.  (BTW, I’m still not looking forward to learning how to work wet fiberglass by myself.)   A few hours with my belt sander made fast work of sanding off the excess fiberglass and getting things close to final.  I also (re)learned to put sheets over my project to keep the dust down some!

When I got my tutorage from Rick, he was pretty even minded about the scotchbrite wheel vs a belt sander, but I’ve developed a distinct preference for the wheel, at least until now.  Now, I prefer the wheel for aluminum, but the sander is very very versatile with sanding/shaping fiberglass!


IMG 4028 V-stabilizer and Rudder Fairings 

46-11 Fuel Return Line

Although not yet published, I did perform the actions on page 46-09 wherein the fuel block gets a 180° flip.  Here, you see the black fuel return/pressure line being routed from the fuel block to the return port and pressure port.  The lavender tie wraps are loose, as there are tweaks still awaiting the fuel sealant to be place on the drip pans.


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Fuel Return/Pressure Sensor Hose

46-10 Engine on Airframe!

Whoo-Hoo!  Major milestone!


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Engine on Airframe

With much anticipation, and the very very very appreciated services of my future son-in-law, Nick; his brother Brandon; and my son, Nick (I know—it’s going to be a confusing family gathering every year...) we were able to hang the engine.  My apologies to my three assistants: it didn’t occur to me to get their photos for posterity.

I was unable to locate a rental engine hoist, and—as much as I don’t mind getting new tools—I couldn’t bring myself to (a) spend $700 and (b) wait 3 weeks for delivery of a hoist, so I simply enlisted these fine young men to do the heavy lifting.  Literally.   

I prepped as much as possible and had purchased two sacrificial AN6 bolts and ground them down to tapers to help seat the engine.  Despite this foresight, they had to hold the engine (about 150 #) for around 10 min before it could be released to set on the bolts.   It then took another 30 min of heaving, lifting, twisting and cursing to get all of the bolts engaged and tight enough that I could take it from there on my own.

One of the more entertaining failure mechanisms occurred while I was painfully trying force the lower bolt from the inside of the plane out through the right lower mount:  the isolator popped out and was found several feet away.  Nonetheless, we got it all together and fit properly.

IMG 4030

Upper Engine Mount

The upper mount deserves some special attention.   Carefully observe the castle nut on the right of the photo: there are 2 full thickness washers instead of the 1 called out by the book.  When the castle nut was torqued properly (more about that anon), the hole for the cotter pin was above the nut.  A second washer solved the problem.  Torquing that nut was a different challenge, however.  Note the extreme limited space for putting a big torque wrench & socket. I used a 6” combo wrench and the fish scale to reach spec.  I overtorqued it about 10-15 % to err on the tight side of the errors inherent with such a kludge. 


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46-08 Reassembly of accessories

The first step on this page is to put back the air induction system and the electronics modules that are physically attached to it.  Right off the bat, I knew I had a problem.  The bottom of the electronic module now bumped directly against the recently installed engine mount (see pink arrow.)  I spent a few minutes growing more grey hair and even taking advantage of fortuitous timing: 10:30 AM EST is 7:30 PST, which happens to be when Van’s Tech support is on the phone.  I talked with a nice guy named Sterling who requested this photo (sans arrow) and said he’d have to talk with the shop and look at their plane to see how it compared.


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After I hung up with him, I remembered fishing out a small metal doo-dad from the crannies on the top of the engine.  At the time, I only had breathed a sigh of relief that it didn’t end up inside the generator housing, where all it could do would be various amounts of damage & mayhem.  What I forgot to do was think about where it could have come from.  Putting two and two together, I put the doo-dad (now renomenclatured as a bushing) below the lower standoff of the electronics control module.  Voila!

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Bushing, now correctly supporting electronics module

OK, back to forward progress.  The Drip pans were built up without too much muss & fuss.  Unfortunately, I don’t have any tank sealant on hand, so that final step is pending.  (Much progress was made anyway.)

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Fuel Return Assy & Fuel Drip Pans

46-07 Cooling Shroud

After laboriously fitting and sanding and fitting and sanding and fitting and sanding... and sanding the shroud, it wasn’t too difficult to attach it and re-attach the cooling reservoir.  There are blobs of RTV under the coolant hoses to minimize wear on the shroud.  


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Cooling Shroud and Coolant Reservoir

Thursday, February 5, 2015

46-06 Engine Mount

Much creative brain power went into the accomplishment of this page.  Taking things out of sequence, let’s address the water pump tubing issue first.  I simply was not able to figure out the 3-D puzzle of negotiating the engine mount into place without seriously injuring the water pump outlets, despite what The Book said.  I also found that there were 2 or 3 other methods that had been discussed on VAF and also by Dave Gamble in his epic books of the assembly of N285DG (“Schmetterling Aviation, The Building of an RV-12, Vols 1-3”).  I tried all of those and realized I was getting dangerously close to frustrated and liable to bend/break something.  That’s when I noted that the good German engineers had used simple reliable techniques for assembling the water pump.  7 bolts later, it comes off easily.  Even better, it went back on just fine.  IMHO, The Book should simply tell you to take the damn thing off, along with the carb’s and cooling system.

IMG 4004

Water Pump without exit housing & exit tubes

While we’re at it, let’s look at some other details in this picture.  Note the small piece of wood under the water pump.  It’s actually under the oil drain banjo bolt and is holding up the south end of the engine.  In the background of the picture, you can see two metal plates that are bolted to the plywood that the engine is resting on.  Funny thing, those plates.  The engine arrived in a crate with those metal plates attached to the inferior engine attach points and to the bottom of the crate.  To make a stable platform for working on the engine, (Big) Nick helped me remove the engine, cut out the bottom of the case and then rebolt it to the wood.  

As I prepared to start fitting the engine mount, I realized my problem:  the engine was currently being supported by the very locations that I was planning on attaching the mount.  I was able to re-position the plates to only bolt to the front end of the engine by putting the wood (which I trimmed to desired thickness) and then moving one plate at a time to just the front. Later, (Little) Nick and Lada helped me lift the rear to put a larger wood block under it to make clearance for the mount.  Long story, short:  I still have a pretty stable support for the engine, as it has positive support laterally as well as longitudinally.


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 Engine Mount bolted to Engine

Nice close up of the M10 bolt holding the mount to the engine, complete with a drop of lacquer for detecting any backing out.  There were some cases of this bolt working its way loose and this was later determined to be due to using the standard torque of 26 ft-lbs instead of the (very well hidden) 30 ft-lbs specified by Rotax.  Of note, Rotax documentation everywhere says to follow the aircraft mfr.’s instructions, and Van’s says to follow Rotax.  The specification in question is found buried in the Illustrated Parts Manual For Rotax Engine Type 912 and 914 Series.  Why this value would be buried down in the parts manual is beyond me.  Anyway, lots and lots of discussion on the use of Locktite and of Nordlock washers. I even found a reference that showed how the traditional spring lock washer can actually promote loosening in some applications.  I think I like the Nordlocks more than Locktite.

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side view of engine with mount 


IMG 4006

rear view of engine mount

The side picture shows a pretty ugly collection of loose tubes & stuff.  Ugh.  I used to think that the engines didn’t look nice to begin with, but now I’ll appreciate them more when everything is attached properly.  The rear view is nicer, and a bit more symmetric except of the weird bulge and the starter motor hanging over on the right.  Oh, well.  Aesthetics are not the important part here.

46-05 Cooling Shroud fitting

This page is predominately about the trimming of the fiberglass cooling shroud pictured on the previous post.  Here’s the engine with the accessories moved out of the way and exposing the top.  The blue things are tape covering the ports for the induction and cooling ports.

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exposed engine

IMG 3997

Inked line on top of engine

The trimming of the cooling shroud took several days (of course, I was working at the hospital for most of them.) It involved trying to put the shroud on the engine top, discovering that it didn’t fit, figuring out where it was making contact, marking that spot, removing the shroud, then sanding/filing/cutting off the marked spot. Repeat ad nauseum.  All in all, it was mindless, dusty, but satisfying work when it finally started to fit.  I guess I removed/trimmed/replaced about 20 to 25 times to get it right.

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Trimmed Cooling Shroud


After getting the shroud trimmed, the cooling hoses come off of the water pump to make it possible to put on the engine mount.  At least, that’s what The Book says.  I ended up going a touch farther, as you will see on the next post.

IMG 4001

Cooling Lines removed from Water Pump

BTW, the clamps that hold the lines on the outflow tubes have been maligned as being difficult to work with pliers and probably have a special tool that only Kaiser Wilhelm may authorize for export.  I found that a pair of cleco pliers worked very well, both removing and re-installing.