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6/23/05 - Misc. Firewall Things - 5 hours

My work on the instrument panel has required me to attach sensors to the engine, which coincides with work that still needs to be done on the firewall forward kit. So, I have taken the plunge and am now knee deep in alligators with regards to all things related to the engine.

The engine is the great unknown for me. I have worked on a couple of cars in my past, including the 'vette I used to own as a teenager (it was a hatchback Chevette!!) The one thing I know for sure is that I don't know much about engine installations, so I have the Bengelis book out, the various instruction and plan pages, and lots of websites at my disposal as I attempt to get everything in place.

I decided to go back to the firewall forward instruction sheet provided by Vans. I have done some of the items already, but I wanted to check them off one at a time to make sure I was doing everything. The first thing I worked on was installing cotter pins in the engine bolts. I had left them unpinned just in case I needed to remove the engine, but we're past that now. The engine stays!

Next, I installed the carburetor on the engine, as well as the control cable attachment bracket. I took the instructions literally and sandwiched the bracket between two gaskets before installing the carb.

Here are two pictures I have looked for everywhere but haven't been able to find. I have wanted to know exactly how the control cables interface with the engine. I ended up just following the plans and blindly drilling holes at the prescribed locations. I made a few minor adjustments to the locations so that I could use the ball things, but looking back, I think they may be overkill. I also wanted to visualize which cables go where in reference to the engine.

So, here you can see that the cable that exits the firewall through the topmost hole is the throttle cable. It attaches to the shorter of the two bracket attachment points and then connects to the throttle horn on the carb.

In these pictures I had not yet installed the nuts that hold the cables firmly in place, but there are nuts and lockwashers on both sides of the bracket attachments.

The second cable to exit the firewall is the carb heat cable. It goes downward and will eventually connect to the air box that I don't yet have installed.

Finally, the mixture cable exits the firewall at the lowest point, and on the -9A it must exit carefully through the engine mount as the nosegear is in the way. The cable makes an upward bend and attaches to the mixture horn on the carb.

Next, I decided to tackle the exhaust. Since I need to attach the sensor wires and other plumbing, I wanted to know where the Big Metal Objects need to be, and the exhaust is the next biggest. Furthermore, before I route any plumbing to the engine, it is probably a good idea to avoid hot exhausts. So out came the Vetterman exhaust kit.

I started with cylinder four. I attached the pipe with the number "4" written on it. Piece of cake. I then proceeded to attach the remaining numbered pipes to their manifold outputs on the engine, using the hardware and gaskets supplied with the exhaust.

This is a bad picture, but it is supposed to show a screw that attaches the oil breather tube to the firewall. Somehow I missed this on the plans, but it clearly says that I need a platenut installed at this location to clamp the breather tube. Ugh. Out comes the angle drill. I drilled out the rivet as called out on the plans. I then attached a platenut using a cleco to mark the locations for the rivet holes. I used the platenut as a drill guide to drill the holes. Next, I had my good helper, Tim, use a bucking bar as a back-riveting plate while I used my back rivet set to set the rivets from inside the plane. OOPS!!! forgot to install the platenut!!! Nuts! I hate it when I do that. So, I had to drill out the rivets and do it again. Finally, the platenut is installed. Now, where is that adel clamp?!

The Spurs are in the fourth quarter with a lead, so I'm not getting as much work done right at the moment, but during commercial breaks I grabbed the B&C alternator and figured out how it installs on the engine. The attachments are all just finger tightened at the moment, but it gives me an idea of what goes where.

So I feel like I made lots of progress today, and the engine doesn't seem quite so mysterious as it did a few hours ago.

8/6/05 - Sensor Wiring - 6 hours

After trying for a while to figure out a routing solution for the magnetometer, I finally decided to run it along the fuel vent line on the left side of the fuselage. To protect the wires from damage, I used a product called TechFlex, which is a plastic "snakeskin" that slides over the wires.

Next came the manifold pressure sensor. For some unexplainable reason, there is no apparent way to mount the box to anything. I guess GRT has confidence that the builders will figure out a way, which is exactly what I did.

I duplicated the hole pattern from the bottom side of the box, onto a piece of .032 aluminum. I then screwed the case screws through the four holes in the corners of the case, leaving the other screws to protrude through the openings I had made. Finally, I put a set of bends in the new "bracket" to allow the device to be mounted.

Here's the diagram that Todd had sent me: trim_wiring.doc

The document describes wiring of one trim indicator. I am installing both elevator and aileron trim, so I did this twice. I used a terminal strip that I bought at Radio Shack to make my connections.

The green, orange, and blue wires from the trim servos are routed to the front of the plane where they are wired using 1K resistors and the regulated power output from the EIS. The indicators can go into any open analog slot on the EFIS, but mine happened to be #4 and #5.

The display setup menu on the EFIS allows you to determine the type of data for each of the analog inputs, and the new software allows you to choose Aileron Trim, Elevator Trim, or Flap Position. There's also a new menu item for calibrating the trim indicators, which allows you to set the travel limits and define any offset for the indicator.

I only have the elevator servo attached right now, so you only see the position triangle for the elevator. Here's where the indicators show up. They also appear in the engine monitor view.

8/7/05 - Sensor Wiring - 4 hours

Next up was the sensors going to the engine monitor. I decided to continue with the terminal strip idea for making the sometimes complicated hookups to the various sensors. The fuel pressure sensor, for example, uses an inline resistor which is really small, so I simply put it between two terminals and made the connections that way.

Next came the oil temperature probe. Out comes the safety wire once again and I did my best to make a mess of it. I guess it will work, but it doesn't have the professional look that the stuff from Aerosport has.

I tested this probe by using my heat gun to blow hot air on the sensor until I could see a change on the engine monitor.

8/10/05 - Ignition Stuff - 4 hours

My order came from McMaster-Carr containing tygon tube and T's. I also received some snap bushings that I ordered from Wicks. So now I have everything I need to complete the manifold pressure lines.

The firewall adapter that cames with Van's FWF kit uses a somewhat smaller diameter tubing, so I used the small stuff from the firewall to the "T" and the larger stuff to the two devices (MP sensor and Lightspeed ignition.)

Next up was the electronic ignition. There is an input connector and an output connector.

I am using a keyswitch for my ignition, so I had to wire the "P-lead" connection on the output connector.

The input connector came pre-wired, but in order to get the connector through the firewall I had to cut off the DB9 connector and then resolder the terminals. This took a while because I got really into making it look just like the "professional" one from Lightspeed. I used shrink tubing on each individual connection after it was soldered.

Working from the keyswitch, I ran power to the main bus. I also ran the wire to the starter solenoid (which you can see here.)

The theory of the keyswitch is to control the mag, the electronic ignition, and the starter, all from one switch. The "OFF" position essentially grounds the mag and the Lightspeed box. The "ON" positions unground the appropriate mag (left, right, or both). The start position puts 12v on the starter solenoid, which in turn "switches on" the starter. I'm writing this down mostly for my own benefit as it is sometimes hard to visualize exactly what's happening.

Here's a top view of the left mag. The connection is going to be to the "P-lead" and the "ground" using a single shielded wire. It will hook up to the ignition keyswitch.

I also need to wire the tachometer sensor wire from the EIS to this mag.

8/13/05 - Fuel Flow, Fuel Level - 6 hours

Here's my solution for mounting the fuel Floscan fuel flow sensor. I fabricated a bracket from some aluminum angle that I am mounting just above the gascolator. It allows me to mount the Floscan sensor so that I can use a u-shaped piece of aluminum tubing to connect between the gascolator and the Floscan unit. My gascolator has ports on both sides, so I will cap the one on the right (as you look at the firewall) and put my 45° AN fitting on the Floscan unit instead. This means there is really only about 2"difference.

Here's the bracket after I "lightened" it a little. It will be attached by two platenuts through the firewall. The Floscan sensor will be mounted to the bracket with two AN4 bolts. I'm happy with this since it doesn't involve adding too much tubing to the installation, and the Floscan unit will be securely attached.

The downside to this installation is that I had to move my ANL. I plan to put it just below the starter solenoid, and probably attach power using a piece of buss bar.

Next, I worked on the capacitive fuel senders. The difficult part of installing these is that they must be available to be calibrated once the airplane is finished. So, I installed mine on the subpanel where I will be able to access them by removing the panel sections.

The BNC connector will connect to the plate on the tank, so I routed it to come out between the fuel and vent lines on the side of the fuselage.

8/17/05 - 8/22/05 - Misc. - 10 hours

This is the first update in a week because I've been doing numerous random little things without any specific goals in mind. I know it's a bad excuse, but it's the only one I've got at the moment.

I spent quite a while routing and connecting the sensors to the cylinders and to the exhaust. I wanted to make sure I had adequate flexibility in the lines while keeping everything orderly and clean.

I drilled 1/8" holes in the exhaust pipes about 2" below the cylinders. These are for the EGT sensors. The sensors are secured with integrated "hose clamps" that fit around the pipes, so it is best to install these on a straight section of the pipe and not a bend. The only problem was cylinder 1, which has less pipe available before the bend than the other cylinders.

I also permanently installed the alternator. I say permanently because I torqued the bolts and installed safety wire, but I guess there is a chance that the alternator may need to be loosened for some reason.

I ran the "big wire" from the alternator, and installed a protective "boot" on the terminal end. I have not yet run the field wire to the regulator, but that will be done soon enough.

The fuel flow sensor was also on my list, so I finished the "U" tube that was needed to connect the Floscan sensor to the gascolator. I ordered the wrong plug for the other side of the gascolator, so I'm going to have to try again the next time I need something from Wicks.

The fuel line has been attached to the sensor and runs to the mechanical fuel pump.

I also worked on the controls that attach to the carburetor. I probably spent more time hunting down the necessary hardware than I did working on the cables. It was fun testing the cables and making airplane noises to reinforce the functionality.

8/24/05 - Cabin Heat - 3 hours

I received the carb temp probe that I ordered from GRT. This little sensor just screws into a tapped hole in the carburetor. I haven't wired it yet.

I don't know if I need to know the carburetor temperature, but it's much easier to install the sensor now than to wait until later, and the sensor was only 28 bucks, so I decided to do it. Who knows, I may be in cold weather someday. Meanwhile it's 102° here in Norte Tejas. ¡Muy caliente!

The SCAT tubing that goes to the heat selector valve on the firewall is routed through a bit of congestion behind the engine. I'm not sure how criticala nice, straight shot is, but I may need to revisit my routing at some point.

I think now I can start to hook up the exhaust hangars. I need to finish up some small wiring issues, like the carb temp sensor. I also need to start thinking about fitting the cowl so I can install the filtered air box.