Scott & Tanya Card RV9A build log (N4822C)

I got both P-mags reinstalled. This is my first time setting up timing on one of these engines. I’m learning new details every day :). Anyway, I found that there is a TC mark on the ring gear assembly that aligns with a point on the starter that matches top dead center of cylinder #1. So I positioned the prop at that point. I used some jumpers to keep the pmags grounded as I applied power to them (coil connector disconnected on each unit to keep the coil from firing the plugs). This put them into “setup” mode. I turned the mag drive gear until the little LED on the mag turned green. This is the point where the crank angle sensor is set at top center. I inserted the mag with all the gears all lined up and adjusted so the green light remained on. This is the manual mechanical timing method for the P-mags as opposed to setting a timing angle offset in the software via blowing in the manifold pressure sensor tubing attached to the mags.
With the P-mags secured, I decided to hook up a laptop with the eicad software. I had previously made a serial interface cable to plug the laptop into some connectors that I ran behind the panel from the mags. Very cool toys.

 

  

  

  

 

This is kind of cool. I’m doing all the stuff that you try to leave off until the end… Time to secure the lower baffles with safety wire. The plastic brake tubing is used as an anti chaffing cover. I just couldn’t resist heat testing this material. It is going to be right up next to some of the hottest parts of the engine, and it would seem like it would just melt away if it isn’t some super duper stuff. I Cut a little length of it for some low tech heat testing. I hit it with the heat gun for about five minutes at about 320 degrees. It did not seem like it was anywhere near going to melt. It didn’t even get very soft, just a little more pliable. Not being content with this result, I took the Mythbusters approach. Now that I am comfortable with the application, just how much heat would this stuff take. So I got out a micro torch and kept bringing the heat up. I shall not reveal how I was measuring the temperature for fear of spousal abuse, but I assure you it was very accurate until the torch came into play. This tubing will take a lot of heat, but it can be melted :).
Now that I was happy with the materials (time will tell), I used .041 safety wire and pre-twisted the center section to a length about 3/8″ shorter than the distance between the front and back baffle flanges to be secured together. I slid that through a cut length of tubing (use the heat gun to straighten out the tubing coil). I cut both ends of the safety wire so I didn’t have to mess with twisting the center section in place under the engine. Actually, I don’t even really see the absolute need to twist the span, but I did anyway. Once in place, I used a steel washer just to provide a little more pull through protection and secured both ends.

It was now time to reinstall the oil filler tube that I took off a long time ago for improved access in that area. Way back when I installed the engine, I was resistant to taking the tube off, and I installed the engine with it on. Don’t kid yourself, it is way easier to take it off early in order to be able to get to all the stuff that goes on down there. As I was putting the oil filler tube back on, it quickly became clear that my ignition wire routing was in almost direct conflict. Bummer. I rerouted the wires in a slightly less desirable way, but all is well.

 

  

  

  

  

  

  

 

Ignition wire installation is done, minus a few adel clamps.

Last session before I closed shop, I put the plenum top on and heated up the glass layup that I had previously done on the outboard inlet ears in order to clamp and shape them perfectly. I took a few more pictures of the plenum top before I pulled it back off since I’ve been getting more questions about it.
Time to get back to work on the ignition wires. I include a picture sequence of the installation of the coil end for amusement. All of the white tie-wraps are temporary. Later I went back and final tied the ignition wires. I even tinkered with using wax wire lacing instead of plastic tie-wraps. That worked quite well, so I used the lacing cord in the locations that were reasonably accessible.
I also got the oil cooler hose fittings torqued and final installed.

 

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

 

I started terminating the coil end of the ignition wires. For recap, this is for dual P-mags with the unshielded auto wire harness provided, used with aircraft plugs in my application. The instructions are pretty straight forward. I’m using DC4 to lube up the boot and wire to be able to push the wire through. A silicone spray as suggested in the instructions would be great if you have some on hand. One tip that I goofed on the first couple of wires: Push the wire through the boot after cutting to length but before stripping it. You really have to wrestle it through the boot and you don’t want to mess up the inner core after it is exposed.
I’m also posting some of my “custom” wiring loom separation. This is only mock-up for wire length and path. After they are all made up, I’ll go back and replace the tie-wraps and pretty things up a little. I ran out of DG12 adel clamps again (for the third or fourth time). DG12 is the size of most of the engine mount tubes (3/4″). I wonder how many pounds of adel clamps I will be carrying around on this thing when it is done.

 

  

  

  

  

 

I applied a couple more layers of glass to the inlet ears of the plenum for stiffness. That was one evening. The next evening was an “RV Dinner” that was a success. I’ll get something real done this weekend.