This site shows the years of construction, first flights, and the continued adventures of Chad and Bekah in our RV-7
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Thursday, May 31, 2012
Oil Cooler Cross Brace
I didn’t have much time in the shop last night, but I did
pick up some aluminum from the Aircraft Isle at Home Depot to make a cross
brace on the oil cooler. This will help
reduce impact of vibration and hopefully eliminate any cracking of the baffles
over time. Again I am not worried about the
extra weight with this type of reinforcement since I have the composite prop
which has saved several pounds by itself.
With this aside from priming and painting, also some changing out bolts/washers for
more appropriate support I am pretty much wrapped up with the oil cooler. Very clean install and I am glad that I can
pretty much call this done.
Monday, May 28, 2012
Oil Cooler !
I have been struggling for a long time with what to do about
the oil cooler. For the IO-375 you need
a bigger cooler than what Vans provides, but how big and how to mount it? Vans offers a 7 tube cooler, Aerosport says
you can go as large as a 13 tube cooler for this engine.. But there is no way that big a cooler can fit
where I need it to. So in the end I
went with a 9 tube cooler mounted per the plans on the firewall. It’s bigger than the 7 but still small enough
to mount per plans. Others have gotten
pretty creative about mounting bigger coolers in the engine mount, or along the
firewall, but in my case I wanted to go with the simple baffles installation. Simple.. Even though, it took all weekend to complete. :-)
Since a 9 tube is larger than plans, there will be more
oil weight in the cooler so vibration is a greater concern as it will be
mounted out near the cylinder head. I
reinforced the mount pretty significantly as you can see so am not worried about
baffles cracking etc. I am not worried
about adding extra weight with the reinforcement since I saved so much
weight by going with the composite prop. I still plan to mount an angle across the front of the cooler for
extra torsional strength, but for the most part, this will be my final install
of the cooler. Rather than saying how I
did it I will just post tons of photos.
Looks good and I am glad it is done !
Tuesday, May 22, 2012
Engine Sensors
It was a fun night working on the plane. I had an hour or so and wanted to work on something other than the cowling again, so I worked through the initial install of the engine sensors. Each of the 4 cylinders gets a cylinder head temp (CHT) sensor as well as an exhaust gas temp (EGT) sensor. I put some anti-seize on the collar of the CHT since it was going into the head of the cylinder and then just screwed them in. On the EGT, I drilled a 1/8 inch hole 2 inches below the exhaust collar on each cylinder. Its key to get them all in the same spot and 2 inches was the lowest I could go on #1 cylinder. Also, in order to avoid conflict with inserting spark plugs etc, I drilled these at a 90 degree angle to centerline. There is no conflict with the cowling.
I couldn’t figure out what was wrong with the oil temp gauge, which should have been the easiest of them all. It seemed to small and would slip right into the center of the port without even touching the sides.. Turns out Dynon shipped some 7/16 inch diameter probes, vs the required 5/8 inch diameter. They will be replacing it with the correct size.
Also I slipped the oil and fuel pressure sensors into the appropriate
spot on the firewall.
I couldn’t figure out what was wrong with the oil temp gauge, which should have been the easiest of them all. It seemed to small and would slip right into the center of the port without even touching the sides.. Turns out Dynon shipped some 7/16 inch diameter probes, vs the required 5/8 inch diameter. They will be replacing it with the correct size.
Monday, May 21, 2012
Misc Firewall Forward
This weekend was another weekend of only limited progress on
the plane. I worked through odds and
ends here and there making only minimal progress. A couple of orders placed to Vans and
Aircraft spruce will allow me to move forward at a faster pace towards the end
of this week. I did run the starter #2
AWG wire and think I got a pretty effective run. Using Adel clamps to secure it to the engine
case and mount as it runs from the starter back to the starter contactor. I also wired up the Tachometer opening cover
I picked up from Andair. Expensive thing
for just a cap, but it was the only one around that allowed for safety wire.. Also, not pictured I torqued the starter
which had been previously removed to fit the engine induction system and worked
on the heat box which previously had been too far forward and was too close to
the cowl. Moving it back helps create
the clearance necessary.
Thursday, May 17, 2012
No More Clecos on the Cowl !
I have been pretty busy epoxying and riveting the cowl
over the last couple days and today before running into work it had cured
enough to set it on the plane. Looks
really good and I am excited about it for sure, but I did learn one important
point. Don’t let epoxy ooze out
between the hinge eyelets. I thought it
wouldn’t be a problem, but the other hinge join interferes just enough to make
it very difficult to slide the connecting rod in place. I have a small dremel bit that I will use to
clear out the excess, so I will be fine, but would have rather avoided the
extra work.
I also was able to install the nutplates on the center cowl join. I used two for now on each side and may add 3 later, but there is a conflict with the flywheel that I want to avoid. Others have stuck with two and have had no issues. I didn't use epoxy here in case they needed to be replaced in the future.
Monday, May 14, 2012
Misc Cowl
It’s been a while since my last update. Things have been busy and I was out of town
for a few days. But in my spare time I
have mostly been working on cowling related items. I got the oil door riveting started. Also, started prepping the hinges for the
cowling. After drilling the hinges into
the cowling, it needs to be countersunk then the hinges need larger holes
between each rivet hole, which is designed to grab the epoxy and flux mixture
that gets put down below the hinges before final riveting. The hinges would hold with just the rivets,
but the epoxy/flux helps with the vibrations and together with the rivets
creates a very long term solution for the cowl.
I also added lay ups over the foam on the inlet
fairings. After an initial filler job
and sanding, I now have the approx. 3/8 to ½ inch gap all around the center
baffle section. This needs more filler
and sanding, then more filler and sanding, followed by the same, then I will
finish the interior with a thinned coat of epoxy squeegeed in place topped by some
white primer suited for oils and solvents and such. Or I may buy some fire barrier designed for
this application, but I understand that is heavy, so we’ll see what finally goes
in place on the interior of the cowl.
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