The RV-6 Rebuild project
Page 4 - Finishing
2020 - I ran across this RV-6 in Albuquerque, NM. It has been
damaged, but was priced about right, so I bought it. Not sure if
it was the right thing to do or not, but now I'm committed. At
first glance, it doesn't look too bad. But then there are all the
things I didn't know that I had to learn before I moved it.
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September 14, 2020 - The crank bolt finally arrived on Wednesday of
last week, but we were leaving for the Light Sport Expo in Mt Vernon,
IL the nextt morning, so I left it sitting on the table until today.
As I often times do, I got absorbed in what I was doing and
failed to take any photo while finishing the assembly. But, from
the previous photos, all I did was install the bolt in the back of the
crank, time the cam, install the accesory cover and oil pan, install
the fuel pump, and install the vacuum pump. And then we have what
you see in the photo above hanging from the engine hoist.
Working on the dynafocal mounts. With 4 long bolts all pointing in
towards the center of the engine, dynafocal mounts can be a bit tedious
The engine is now hung on the airframe. I have a
couple of days of work to hook up the controls, wiring, and plumbing.
September 15, 2020 - Didn't get much done today. Spent the
morning dealing with an obstinate company (Lifelock) that's trying to
screw with my mother's estate, flew the Cub to Gaston's for lunch with
some friends from Kansas City, then flew the Cub to Calico Rock for
Burgers & Brats this evening. I did get the thermocouples all
hooked up. Then I hooked up the oil pressure line and found the
pipe thread end of the fitting in the mirror above is not tight and
sure to leak. The mount is in the way so it can't be tightened.
(This might explain a lot of the oil scunge on the belly of the
plane as I never took this fitting out of the accessory case!)
I'm going to have to at least loosen up the engine mount to get
this fitting out. I should be able to mount it where you see the
hex head plug also in the mirror. Sure wish I would have known
about this problem while everything was out on the bench or on the
engine stand. Now the engine mount is kind of in the way. I
hope to get this fixed tomorrow, but will also be flying the Cub to
Mountain View to meet another friend for dinner, so once again, work
time is limited. That's a lot of dining out for someone that
really doesn't eat much. It's a social thing.
September 16, 2020 - Compare this photo to the one
above. I have the plug out of the second hole and a plug in where
the fitting was. I could not get enough clearance to screw that
fitting out without pulling the engine off the mount, so ended up
cutting the top off the fitting with a die grinder and threading out
the remains. The plug was also really stuck in the hole I need to
use. I finally applied the propane torch to the case for a minute
or two to warm it up enough that it finally popped loose without
stripping the allen head. I put a new plug in where I removed the
fitting and ordered a new restricted flow fitting from Aircraft Spruce.
This just shows the cleanup of the wiring under the
engine. I really try to keep the wiring as tidy as I can and pull
it down under the cylinders rather than the heads as cylinder cooling
isn't terribly important. But cylinder head cooling is critical.
Note that the starter also has the wiring connected now.
The same cleanup under the cylinders here. I'll clean up the back as I get more stuff installed.
September 17,2020 - What is this part? This part
is the mount for the throttle cable. I replaced the original Vans
supplied throttle cable with one that I liked better from ACS products.
So, of course, the cable didn't fit, or even mount in the same
way. I fabricated the U shaped collar to capture a slot in
the throttle cable. The two screws toward the right hold the
slotted collar in place and the 1/8" plate at the bottom captures the
bottom of the collar.
The throttle mount clamped onto the engine mount with the throttle cable mounted into it.
Carb heat control also connected. Note the safety wire around the
adel clamp on the cable. Several wraps of .032 safety wire
will wrap snugly into the grooves of the cable sleeve. Putting a
few wraps on either side of the adel clamp, then twisted tight ensures
the cable sleeve won't slip in the clamp. I did the same with the
mixture cable as well. Carb heat in this installation works by
closing a flapper valve in the ram inlet of the airbox changing the air
source to the heat exchanger just above the air box.
September 18, 2020 - After spending a couple of days
working on other tasks while ruminating over how I want to build the
baffling and where to mount the oil cooler, I decided to get started on
it today. The right side is really pretty much according to
plans. I still need to add a stiffener or two and the seal along
to top. Pretty straight forward and easy.
I finally decided to relocate the 7 vein oil cooler to
the back of the baffling per the Vans plans. It was previously
mounted in front of #2 cyl requiring long oil lines strung over top of
the cylinders. It also had a small scoop to augment the air flow
into the cooler. But the insides of this engine was telling me
the oil temp had been running a bit warmer than I want to see. I
had planned to use a 10 vein oil cooler, but it won't fit on the back
side of the baffling due to interference from the engine mount.
Notice the dull colored baffling segment on #4 cylinder. I
fabricated this piece from stainless. It seems that every RV
baffle kit I see with the cooler mounted to the aft baffle has the
baffling cracked around #4 cylinder. This happened the first year
after I finished the Cub as well (I used the RV baffle kit for it).
I fixed the Cub baffling by fabricating the baffle around #4 cyl
from stainless. Hopefully I've headed off the issue on this plane
by using stainless around #4 cyl from the beginning. Of course
while cutting out this piece of stainless, I stripped the drive on my
portable band saw. I had to drive to Batesville to pick up a new
band saw so I could finish the job. That took a couple of hours
out of my afternoon. I expect the baffling will take another two
or three days to finish.
September 19, 2020 - I've been thinking through the details about how
to mount the oil cooler for the last couple of weeks. Today it
was time to get it on there. It looks like so little to get
accomplished for the day, but it was a lot of work cutting out the
various little parts to reinforce the back and side of the baffling to
support the oil cooler. There is a .125" 6061-T6 Aluminum
rectangular window frame under the oil cooler to reinforce the back
plate. There are two .125" 6061 Aluminum filler plates between
the back panel and the side panel. All of them needed to be
custom cut and match drilled. Sharp eyed observers will note
the stack of 6 washers on the lower bolt mounting the far side of the
oil cooler. I needed to do that to keep the bolt from digging
into the cylinder head fins on the other side. I'll get a
measurement and will need to order a shorter bolt to replace that one.
Most days at the airport are pretty quiet. Today was filled with
interruptions. A few phone calls, friends stopping by to check on
the project and a new friend that's a state trooper stopped in to see
what I was up to. He left with a promise for some time in the
SuperCub tomorrow afternoon. I really don't mind the
interruptions and enjoy talking airplanes with anyone.
Tomorrow I can get a measurement for the oil lines and will get them
ordered on Monday. Not sure yet whether I'll have the local
hydraulic shop make up some hoses for me, or whether I'll order the
integral firesleeve teflon hoses. I'm leaning towards getting the
pricy teflon hoses made up for it. I used them on the Cub and
really like them. I'll likely order a new fuel line of the same
material as well. It kind of depends on how tight the space is
for the hoses. The Teflon hoses are really stiff and can be
difficult to install in tight confines where they need a tight radius
September 21, 2020 - The last couple of days have been
an exercise in patience and frustration. It must have been a
Friday afternoon when Vans packed this baffling kit. It has
extra pieces from other baffling kits in it (like an extra back to go
behind #4 with a part number that doesn't belong in this kit) and is
missing a lot of the small pieces (mostly brackets) that are supposed
to be in the kit. This is not the first time I've used the RV
baffling kit, but this one seems to be significanly slower to build
than the one I used 9 years ago. I finally decided to set the
plans aside and just build it with what I have and finish it with
aluminum stock I have on hand. I have been trimming the top of
the baffling down little by little until it finally fits under the top
cowl. I have been adding braces and gussets here and there until
it is now quite stiff. Now I need to take it off and rivet it
together, then add the chafe seal all around the edges. It will take
another day or two to finish. I took the measurements for the oil
and fuel lines. They are short enough with 90° bends that the
Teflon integral firesleeve hoses are going to be too stiff to install
in that short of a run. I was going to have the local hydraulic
hose shop make up the lines, but they use machine crimped aluminum
ends on the hoses. Those aren't commonly used in aircraft, so I'm
a bit leary about installing them in mine. So, I decided to order
Airquip hoses, fittings, firesleeve and mandrels and will build my own.
The photo above is the front half of the baffling held together with
Clecos at the end of the day today. Maybe I'll be able to get
started pounding rivets tomorrow. I have had to fit the cowling on
and off many times. It would be so much easier if I had a second
set of hands to help hold the cowling while I slide in the hinge pins.
Septermber 22, 2020 - Forgot to take photos today. The summary is
that I continued to work on the baffling, and will continue to work on
it again tomorrow. So, new pictures tomorrow.
September 23. 2020 - I took this photo just after starting this morning
to make up for the lack of a photo yesterday. I'm still piecing
together the baffling. It's just tedious work.
The baffling seems to be complete. I added a 2" air pickup on the
back right to feed the cabin heat and a 1" duct on the back left to
duct cooling air to the gascolator.
I also mounted and rough timed the magnetos, although I need to use the
mag tweeter to dial them in yet. I also have some cleanup to do on the
baffling as I have a lot of notes and markings on the baffling written
with a sharpie. I have one more fitting and hose to install on the
back of the engine and need to install a ground strap from the engine
to the airframe. I've really beat up the paint on the valve covers
with installing and removing the baffling several times, so took them
back off to repaint.
September 24, 2020 - Not much to show visually. I
continued with the fit and finish on the baffling and the baffling to
the cowling. I think the baffling is now complete. I put
the tweeter on the magnetos and finished timing them. I cinched
up the bottom side of the baffling under the cylinders so the
intercylinder cooling baffles are now tight to the cylinder and
cylinder head fins. They are tied with .041 safety wire.
I have all the ignition wires routed and hung with the exception
of the two seen here hanging on the left side. The prop extension
is now torqued and safety wired. The mufflers are now hung in
place, although I still need to find and install the clamps to hold them
September 25, 2020 - The mufflers are now clamped on and heat exchanger
for cabin heat is hooked up. New spark plugs are installed and
ignition leads are now routed and secured. I also tidied up all
the wiring under and behind the engine.
I fabricated the 3/8" fuel line and added firesleeve to it. You
can see it just below the oil cooler and above the left side muffler.
Looking down behind the engine. You can see that the fitting for
the oil line that goes to the oil cooler is still open and the oil
filter has still not been installed. I'll make up the oil hoses
tomorrow, then install the oil filter. Then the engine will be
complete and ready to start.
Looking on from the front. I pulled the prop through 4 blades.
The compression is certainly nice and tight. That was
enough to prime the oil pump as it promptly puked oil out through the
oil filter housing onto the floor. The fittings arrived for the
1/2" oil hoses today, so that will complete the engine tomorrow.
I'll plan to do the W&B on Monday, then will be ready to fuel
and fire it up.
September 26, 2020 - I fabricated the lines to the oil cooler.
That should complete the engine install. Just add fuel and
it should be ready to fire up for a leak and functional check.
The previous owner re-used the same spinner after bending the prop and
replacing it with a different prop. Consequently, it has two sets
of holes for the front bulkhead due to the different thicknesses of the
props. Add to that the poor workmanship of the holes, and I
decided to fill and smooth over the holes, then will re-drill them.
Inside the spinner. I filled the holes with epoxy resin and
milled fibers, then laminated two layups of 5.8 oz tooling cloth on the
inside of the holes. The white patches you see in the photo is
the peel ply over the wet layups. I'll pull the peel ply in the
morning and the spinner should be ready to drill new holes.
I didn't like all the screws that hold the upper cowl on, so am
converting to 1/4 turn camloc fasteners. I drilled the holes out
bigger to accept the camlocs.
I also drilled out the rivets mounting the nut plates so I can
rivet in the camloc receptacles. Of course the aluminum piece on
the front cracked when I drilled it, so had to fabricate a new plate to
mount the front receptacles. And, of course, the rivet pattern
for the receptacles doesn't quite match the pattern for the nut plates,
so I will have to drill and countersink all new holes. While I
was drilling out one nut plate, the nutplate fell off and went right
down the inside of the gear leg fairing, so I'll need to remove the
fairing to get the nut plate out.
September 27, 2020 - The Camloc receptacles clecoed into place ready to be riveted on.
Camloc fasteners in the cowl. I am short a half a dozen #10
length Camlocs to go across the back to fasten onto the boot cowl.
I bought enough to do it, but it turned out that 6 of the
fasteners in the front of the cowl were one size too short So the
#10 fasteners got used there and I had to order 6 more for the back of
the cowl. I also finished the glass work on the spinner and
installed it, but forgot to take photos. I'll post them tomorrow.
We'll see what else crops up once I try to fire this up, but at
this point in time, all I have left to do is the W&B then fire up
the engine for a leak and ops check. Then once the logs are done, it
should be ready to fly.
Spinner photo was added later. You can clearly see the filled
holes in the spinner. Eventually, I'll fill again with
micro-spheres and paint.
September 28, 2020 - Weight and Balance day. It came out pretty
good and is 18# lighter than it was when it was new. I
expect most of the weight loss was the weight of the damaged metal Sensenich prop that was
on it being replaced by the wood and carbon fiber Prince Prop.
After completing the W&B, I rolled it outside and splashed some
fuel in the tanks, then attempted to start it. The batteries
couldn't turn the engine through the compression stroke. I put
the batteries on the charger for the night. We'll see if
they can fire it up tomorrow or if I need to order new batteries.
Knowing the plane hasn't flown in many years, I expect I'll be
ordering new batteries tomorrow afternoon.
September 29, 2020 - Nothing to show other than two useless batteries.
This plane has a 24V electric system using two Mor-Co AGM
batteries sized and rated the same as the Odyssey PC-680 AGM batteries.
The date on the batteries is 8/18, so they are only 2 years old.
They appear to take a full charge, but are not sufficient to turn
over the engine on the batteries even after spending the night on the
charger. I have two Odyssey PC-680 batteries coming, so it's
unlikely I'll get to fire up the engine before this weekend.
Additionally, I found the electric rattle pump is not capable of
enough lift when dry to pull fuel up to prime the system from a nearly
empty tank. The rating for this pump is a maximum of a 12" dry
lift. Note to self: Never run a tank dry since it can't pick up
the prime from a low tank.
October 1, 2020 - Package arrived from Battery Mart. No time
to install batteries this afternoon. Maybe I'll finally get to
fire up the engine tomorrow.
October 2, 2020 - OK, batteries are in. Time to light the fire...
WHAT IS GOING ON HERE??? Well, time for a confession.
When I ran the engine, it started and ran just great, for about
20 seconds. Then it ran out of fuel. I turned on the
electric pump and started it back up. The engine run went well.
No fuel leaks and no oil leaks. However, as soon as I shut
off the electric pump, I would lose fuel pressure. Evidently, the
mechanical fuel pump wasn't working. I ordered a new pump, then
removed the old one. As soon as I had the pump out, the problem
was obvious. I had installed the pushrod that runs between the
fuel pump cam and the fuel pump upside down. As soon as I removed
the pump, the push rod fell out of the accessory case and into the oil
pan. Not a problem to retrieve it, but the only way to install it
properly is to remove the accessory case. So, I removed the oil
pan and accessory case. The pushrod was indeed laying in the oil
pan. Of course I damaged the oil pan gasket when I removed the
pan, so now I'll be waiting until next week to get in new pan and
accessory case gaskets before I can reassemble. Since I have a
new fuel pump coming, I'll be installing it as well. Maybe the
first flight will be coming up next weekend.
October 13, 2020 - OK. Time for more true confessions here. Notice the
with the cam on it in the photo above? That cam is to actuate the
fuel pump. But, the gear is in the wrong place. The idler
gear with the cam for the fuel pump should be sitting between the crank
and the camshaft. Instead, it is sitting in the position of the idler
that drives the prop governor, which is not installed on this engine
So, I had a few days of frustration after putting the engine back
together with the idler gears swapped around. It ran fine, but
still no fuel pressure when I shut off the electric pump as there was no cam in place to run the fuel
pump. Of course I didn't realize that yet, so swapped the new
fuel pump out for the old one, then found that it still didn't have any
fuel pressure, After reviewing the photos and some discussion
with the local mechanic, it suddenly hit me. Oh crap. The
idler gears are swapped into the wrong places. So, I tore the
engine back down to the status shown in the photo above. In the
photo below, you can see the idler gears in the correct positions with
the cam for the fuel pump on the gear to the left.
This is the rod that was installed upside down. There is a round
cam follower head toward the right, which also keeps the rod from
falling out of the accessory case. But note that the top of the
fuel pump rod is pointing at where the cam for it should be... between
the crankshaft and camshaft, not below the crank as I had it
configured. This is stuff that is really obvious. Makes me
feel pretty dumb for making such a silly mistake. But I have paid my
dues for it with a week of frustration.
So, the oil sump accessory case, mags, both fuel pumps, and the vacuum
pump are all out sitting on the bench again. Everything is
cleaned up and ready to go back together. I need to move the
fittings from the old fuel pump back to the new one and will install
the new pump since I have it. New gaskets will arrive tomorrow
afternoon and I'll get started reassembling again on Wednesday.
October 14, 2020 - If nothing else, I've had practice taking this
engine apart and putting it back together again, so am organized and
reasonably quick about it. Today I reinstalled the oil sump, the
accessory case, the fuel pump, the vacuum pump, installed and
timed the magnetos, installed the carb and intake tubes,
reinstalled all the engine controls, oil lines, vacuum line, vent line
and electrical connections, reinstalled the spark plugs and ignition
harnesses, reinstalled the exhaust and reinstalled the dipstick tube.
Left for tomorrow is the oil filter, fill it with oil, cowl it
up, and install the prop and spinner. Unfortunately, the airport
is closed while the runway markings are being repainted, and this
weekend's weather isn't looking great for a first flight, so it may be
next week before I can get this into the air. But there is no
reason to hurry at this point in time.
Octobrt 15, 2020 - It finally looks like an airplane again. The
things that are supposed to pressurize, suck, blow and pump are all
doing what they are supposed to do. So, now it's cowled up and
ready for some ground testing, then flight testing. The only
notes from taxiing it this morning are that I was getting a high temp
warning for #4 cyl due to the EGT and CHT thermomcouples being
switched, and a low suction light despite the vacuum gauge showing good
vacuum. Those have been addressed, so now it should be ready for
ground and then flight testing.
I did wash down the firewall and engine with solvent and scrubbed the
belly. Then I taxied it over to the maintenance hangar and washed
it. Once back in my hangar I wiped it down and detailed it.
At least we'll start out with it looking pretty.
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Comments or questions; Email me firstname.lastname@example.org