Scott & Tanya Card RV9A build log (N4822C)

I’ve been continuing to sand and fill on the cowl for general shape. I’m planning on applying my first full coat of primer (UV Smooth Prime) soon. I spent one evening sanding the inside of the cowl with some 80 grit paper in prep for interior finishing with thinned epoxy to make future cleanup easier. I put the cowl and spinner back on the airframe for the first time since completing the side hinges and spinner. Looks good and I’m happy with the results. I think I have decided not to put a bunch of effort (we’ll see) into the cowl spinner ring. It just doesn’t matter if it is straight, square, smooth, etc. It is behind the spinner!

 

  

  

 

I took a “build day” and spent the majority of the day working on the spinner. I have it fitted and all of the holes located and drilled. I put a huge chunk of time into fabricating the filler plates behind the prop out of .063″ sheet. I got one of them done and will complete the other one with just a little more work.

 

  

  

  

  

 

I got the carburetor, control cables, and airbox mount plate installed “for real”. I prepared the intake gaskets with a little bit of fuel lube and a roller between some plastic. I had to adjust a washer for the carb temperature probe since it protruded a bit too far into the venturi without. The threads for the probe were also prepped with a bit of fuel lube (great stuff). I took a quick picture of what must be the idle mixture screw for future reference. The airbox mount plate that attaches to the carburetor has four 1/4″ bolts that screw into the carb. These are inside the airbox and if they were to come loose, they would surely be ingested by the engine with catastrophic results. Hence, they use these little tabbed washers to safety them. The bolts are torqued and the tabs are bent up. Before deciding to use the tabbed washers, I attempted to drill the bolt head for safety wire. These are grade 8 bolts and I made a number of attempts to drill the head, each resulting in a broken drill bit. I replaced that bolt and abandoned that idea for the vans tabbed washer solution. After I got the carb mounted to the engine and bolts/nuts all torqued, I moved on to finalizing the control cables. “Final” assembly of stuff is fun after all of the temporary work.
Commitment time… I decided to go ahead to seal up the firewall penetrations. This came about because I’m trying to complete things that are difficult to get to toward the center of the firewall and bottom of the engine. This means the engine control cable pass-throughs. Of course that leads to all of the other wire penetrations. We’ll see if this was a good idea or not at this point. I used some expensive 3M fire caulk stuff that I got from ACS. I injected it into a syringe in order to get into all of the tight spots on the firewall. That worked pretty good.
Next up was to final secure the exhaust system and EGT probes. The Vetterman exhaust comes with some blow proof gaskets that can be reused. I was able to get to all of the exhaust header flange nuts with a simple 1/4″ drive socket and universal joint. Apparently these nuts are much more difficult to get to on other engines. I used some anti-seize compound on the stud threads and torqued the nuts. Once the headers were on, I drilled the holes for the EGT probes on each pipe. On the right ones, I positioned the probe to be sure I could get to the spark plugs with a socket. I spent a little time dressing the probe wires.
About this time, Tanya made an appearance in the garage. I was quite surprised. She has been avoiding the garage for the last couple of months since I put on the big push for progress. Side note: I’ve been working on the project every moment of every day for the last couple of months. This is in an effort to complete before the heat of the summer makes final assembly in the hangar unbearable in the 100+ degree heat. It will be close if I make it. And now we *both* want this thing to fly so we don’t have to be renting beat up old airplanes. So I gladly put Tanya to work assembling the exhaust tail pipes. A good simple task. After she was done with that, I went to work doing the final assembly of the exhaust hangers. Tanya then worked on making a cutout template for the prop spinner. That was a bit time consuming. I’m so thankful for the help when I can get it.
So, with a near perfect cardboard template for the prop cutout in hand I traced it onto the spinner. Yes, I fretted about placement and orientation a sufficient amount. I finally just took the plunge and made the cuts. The spinner fit around the prop almost perfectly as I trimmed right up the the marked lines from the template. Much trimming and adjustment is still needed on the spinner but I call this major progress.
I’ve also been doing some small bits of filler on the cowl as I’m doing other stuff. After I prosealed and riveted the hinges on the cowl sides, the top and bottom edges were not perfectly flush with each other as they were before. Major bummer. I must have not evenly (same thickness) applied the proseal. This kept me up at least one night. With a combination of sanding the high side down a tad and filling the low side a bit, I think I’ll be able to get it close enough for me. So, that is what is currently in process with the cowl.

 

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

 

I feel like I’m just tinkering with little details again. I covered the wires that snake around the bottom of the engine that go to the alternator and starter with fire sleeve. They are secured to the sump with adel clamps. Added two braided ground straps, one very short just to the engine mount, the other is longer that goes to the firewall. I also worked out the hardware details of the engine control cable hookups. I found that the cabin sub-panel extension that I did for securing the control cables still wasn’t low enough so I had to work up a little bolt post to suspend the control cables another inch lower. The symptom became obvious when I hooked up the cables to the carb and there wasn’t enough slack in the cabin to get the center tunnel cover (with the holes for the cables) on. It worked out.
I cut the carb heat control cable to length. I used some simple bypass cutters to cut the jacket. I had intended to just roughly cut it to length, then clean it up with the dremel. I was amazed to find that I didn’t need to tough the cut end. It was perfect by simply chopping it off with the cutters.