Feature

Installing a FADEC system

by Noel Simmons

I have been toiling in the shop on an RV-7 with the Mattituck TMX IOF-360.  Some people have asked me to post  my experiences with the installation of the FADEC. 

First impressions:  WOW!!!!!  The connectors are idiot proof, the wire harness just about fits perfectly as it comes, each and every end is labeled very clearly.  And most impressively, It works most impressively!!! But read on there are some "gotchas" and "I wish I would haves the first times." Yes my next RV will have the FADEC, and using what I am telling you now it will be much easier. 

One major note about Mattituck and Aerosance.  These are real professionals that work together with the up most professionalism.  I did have a problem on the first flight.  Cylinders2 and 4 would drop off line below 54 percent power.  The CHT would climb above my personal feel good limits above 62 percent power so I felt that I only had an 8 percent margin between flying and landing.  Both Jabe from Aerosance and Mahlon Russell from Mattituck came to my shop and worked until midnight the first day and noon on the second day.  Each had traveling orders to not come back until it was fixed.  This is why I deal only with exceptional companies like Aerosance and Mattituck! 

This is not my first RV, but it still is a very nice example.  Here is a general overview of the project.  RV-7, TMX IOF-360, three screen GRT EFIS, 430W, SL-30, GTX330, Mountain High Oxygen, Aero Classics leather interior with heated seats, center consol, BSA plenum, Duel electrical system, Light speed wheel pants, Grove BIG brakes.  

To start out:  Let me tell you why the FADEC is worth the extra mile during construction.  I did not full understand just how great of a system this was until I got well into the flying.  Now I fly and let the FADEC do everything else.

* Start is easy!
* Primary FADEC, on
* Right and LEFT ECU (A&B), on
* Fuel pump, AUTO
* Throttle cracked open
* Push start button until start (usually 3 revolutions)
* Engine performance is referred to by  percent of Power
* RPM / manifold PSI are all factors of  percent of power
* What I am saying that with in reason RPM and/or MAP doesn?t matter just set the RPM to the noise you want and the throttle to the airspeed you want.  Enjoy!
* Take off full RPM and full throttle
* FADEC takes care of the engine
* FADEC leans for best power
* FADEC keeps CHT below 450 deg.
* Sounds like a lot YES but that is what it is designed for!! YES the CHT comes down!  YES the CHT will never become uncontrolled.  The FADEC will manage the engine to peek performance.

* Cruse is done were you set the  percent of power
* 70 percent OK
* 75 percent OK
* 90 percent OK
* 94 percent OK
* Get the idea it doesn?t mater, the FADEC manages the engine so you can just enjoy flying.
* At 6,500 feet, temp greater than 85 deg I can only pull 72 percent power.  I get a True airspeed of 178 knots at a fuel flow of 12.4 gallons per hour.  Not to shabby!
* Decent is a breeze too, the FADEC keeps the CHT up so shock cooling is another thing of the past.  Yes I think if you chopped the throttle closed you might, but do try to be a little further ahead of the aircraft than that.

ORDERING
Ordering is done though Mattituck, 1 877-777-1870, talk to Michael Yousik, using this advice you will know what system you want and what parts are coming from Mattituck and what parts you need to order directly from Aerosance. 

1. Know exactly how your electrical system will be configured and tell Mattituck and Aerosance. 

a. Your basic choices are as follows, good to adequate 

Dual alternators with duel batteries
     -Three switch on the panel A buss, B buss, interconnect
Single alternator with Aerosance back up battery
      -Just a normal Master switch, the back up battery is waiting in the back ground for something to do.
Single alternator with single battery
      -Not a good idea, if for any reason the main power source goes out you will wish you had another.

The first choice is the best, there are different blind boxes that go behind the panel.  There are also two lights you MUST supply.  FADEC warn FADEC caution.  This is the cheapest system because you don?t have to buy Aerosance?s battery and box to maintain it.

Choice number two is good to, this is the choice Mattituck will send you if you don?t specify you have the duel alternators and duel batteries.  This system requires a ?FADEC warn enunciator panel? that takes up a little real estate on the panel.  Note there is only a horizontal model even though the Aerosance web site has a vertical model.

You can run the FADEC with ether a constant speed prop of a fixed pitch prop.  If you are using a fixed pitch prop you will have to supply one additional light to place on the panel that illuminates when you are at full throttle.  

If you are connecting the FADEC to an EFIS you will need the serial buss converter

There is a data capture device you will have to mount under the panel too.

Plan on mounting three boxes under the panel, and an additional two boxes, ECU;s on the engine side of the panel.  You will have two cannon plugs that need to pass though the fire wall, and TWO sources of power will also have to pass though the fire wall..

First here is a quick reference of terms used though out, and some pictures and details of my latest Simmons RV-7.

* HSA  ~health Status Enunciator
* Connects on the panel side of the firewall
* Senses the flow of current from or to the back up battery
* Charges the back up battery
* Illuminates the proper lights on the horizontal light bar

* ECU ~electronic control unit
*  Two in the system. Mounts on the fire wall engine side
* These make the spark plugs fire
* Reads the crank position sensor (located were your mag was)
* Activates the coils over the fuel injectors
* Two giant plugs get screwed in to these so mount them so you can get to the plugs easily.

 SBC ~Serial buss converter
* Lets the FADEC system talk to my EIS from Grand Rapids Technology
* Mounts on the panel side of the firewall

 Light bar assembly vertical not available

 Light bar assembly horizontal  
* Mounts on the panel
* Connects to the HSA

Two light HSA ~similar to the above HSA
* Less complex because it does not have to keep a second battery maintained,
* Is used only with the duel buss electrical system.
* You have to supply two lights on the panel
     - FADEC warn
     - FADEC caution

Installation:
Quite straigt forward really.

 The engine runs hotter than that witch Van?s has engineered the firewall forward kit.  Keep plastics away from the cylinders and exhaust.  Put heat shielding on the bottom of the cowling.  The plastic tubing that acts like anti-chafing over the safety wire holding the bottom of your baffling will melt and drip on to your exhaust.  A great remedy is to use some #6 ready rod that you can bend away from the cylinders.  
  
The Fire wall seams to get a little crowded, I strongly suggest you not touch the fire wall until all the parts show up in the big box from Mattituck. 

  

    I mounted on the engine on the mount permanently, but the engine mount itself was not finalized, it was just temporarily held tight to the firewall with bolts.  I could place all the parts on the firewall one at a time and out line them with a marker.  After the engine mount was removed I could then mount everything on the firewall with ease. 

 I mounted the ECU?s were Van?s wants the Odyssey battery to mount.  The ECU?s bolt on a special mounting plate that comes from Mattituck under the ECU?s.  The ECU?s only bolt to the mounting plates in one direction, and are designed for cap screws not the ¬? bolts that are supplied.  However the ¬? bolts will work you just have to use an open end wrench.  One mistake I made is mounting the ECU?s so the plugs point inboard, what a pain to install the plugs.  These should be mounted down, it will make inspection easier too. 

 One other thing to consider while locating the ECU?s is the fuel line coming out of the engine driven fuel pump.  The cleanest way was to actually place the ECU so the fuel line runs directly between the spark plug towers.  An inch up or down and the spark plug towers interferer with the engine mount, fuel line, oil cooler, ect. 

 The Odyssey batteries were mounted high on the firewall the battery box will have to be removed for the removal of the batteries.  The battery boxes use nut plates any way so this should not add much to future maintenance.  Be careful with the location of the master and starter relays, you could easily get one of these to hit the engine mount. 

 The wire harness just about fits the way Aerosace builds it.  To start drape it over the engine.  Sort the EGT and CHT probes, you will easily see witch cylinder they belong to by the giant number on each of them.  The Manifold temperature and Pressure sensor connectors need roughed to the bottom of the engine too, this took some separating of the pre-assembled harness by removing some of the ties.  The top of the engine gets both the fuel pressure plugs and the four coils that activate each of the fuel injectors.  The remaining plugs are two that go to the crank sensor located on the back of the engine accessory cases were the magneto went.  Each of the ECU?s that you mounted on the firewall get a giant plug.  The Firewall has two plugs that pass though.  Seams really simple now that I have done this once. 

 The spark plug wires also need to be routed.  Aerosance has these labeled too (1 top, 4 bottom, ect.) The length of the leads seams a little odd, some were a little short and some were excessively long, I simply got the lengths for the routing I chose and moved the labels.

 Most likely you will want fuel flow and to do that you will need a fuel flow transducer from your EFIS supplier.  The FADEC does not calculate fuel flow.  We mounted the fuel flow transducer on the firewall.  The fuel flows from the airframe mounted electric fuel pump though the firewall low because of the cockpit kick panels, to the engine driven fuel pump, to the fuel flow transducer on the firewall directly to the fuel distribution block on the top of the engine.  Quite easy!  All the fuel metering is done directly at the cylinder by the pulses of the fuel injectors. 

 So far pretty much strait forward, now here is were I had the toughest time and it is simply the difference between a regular fuel injection and the FADEC, please pay attention and this will be easy for you. 

The fuel injectors are vary special!  They have moving parts and springs in them that are actuated by a coil that slips over the outside diameter of the fuel injector and is held down by a very thin nut. 

STOP!!!!!!!

You will receive your engine from Mattituck with out the coils over the fuel injectors.  So you have to remove the fuel injector line ?B? nut.  ANY and might I say ALL the contamination in the world WILL end up in the top of the injector.  Resist the urge to do this now. Leave them alone! You will not need the fuel to the engine until you are ready to start it up and then and only then can you properly purge the fuel system before connecting the fuel injector lines to the fuel injectors.  The next paragraph will explain in detail how to purge the fuel system of contaminants BEFORE you run contaminated fuel into your fuel injectors.  You will need several quart sized jars and a gallon bucket, these need to be hospital clean, paint mixing pales work great.

      Today clean your tools before you start work, it is absolutely imperative you have a 3/8? deep socket that is perfectly clean in side!  Buy a new one!  The the socket will be used to tighten the little nut that holds down the coil so it will have to go over the exposed injector (that is why the inside must be perfectly clean).   You will have to grind down the out side wall a little to clear the wires attached to the coils

      Step 1
       Disconnect the fuel line going to the fuel distribution block on top of the engine.  Put the end in your hospital clean gallon bucket, turn on the eclectic fuel pump and fill this bucket up ?.  Check for contaminates, even the smallest!  Continue this step until you get two buckets in a row that have 0 bits of contaminates.  Reconnect the fuel line to the distribution block.

      Step 2
       Disconnect each of the ?B? nuts from the fuel injectors.  PUT a cap over each of the fuel injectors so NO contaminants can get in the very little hole in the top of the injectors.  Place each of the fuel injector lines into a hospital clean quart jar.  Turn on the electric fuel pump and fill the quart containers ? full.  Check for contaminates, if no contaminants are found fill the containers again and check.  For those of you who are a little more studious you can also check to see that your fuel flow is working, you should see a fuel flow over 30 gallons per hour.  Any and I mean even the smallest trace of contamination you should continue to run fuel though the injector lines until the fuel samples are completely clean.

       If you continue to have contaminates in the fuel you will surly foul your new injectors.  You should at this point take the four cap screws out of the top of the fuel distribution block and checked the filter and the flat rubber seal that seals the filter.  You should easily be able to blow though this filter.  No contamination should be on the bottom of the fuel distribution block down stream of the filter.  If the filter is clogged, or one of the seals has been damaged replace them with new ones. 

      Again flow fuel though the system and catch the fuel in 4 quart jars at each ?B? nut on the end of the fuel injector line.  After you have successfully captured two perfectly clean samples of fuel from the ends of the fuel injector lines you may now precede to complete the pluming of the fuel injectors.

      Step 3
      You will need to take off the cap you have covering the fuel injector and slide the coil down over the fuel injector body.  Carefully start threading one of the thin nuts on the fuel injector.  Take your new modified 3/8 socket that is hospital clean inside and out and torque the little nut down making sure the coil wire is clocked the direction you desire.  You will notice that there are two places on the treads were Aerosance swedges the injector parts together.  These will cause the little thin nuts to bind a little, don?t worry about it just keep on task and torque the little nuts down.  

      Put the fuel injector line on the top of the fuel injector.  Tighten the ?B? nut by hand.  Then torque the ?B? nut.  DO NOT over torque this you will damage the fuel injector, and bad things will happen, like, you buy a new one.
     
      Great you have the fuel system completely purged of things that will cause the fuel injectors to shoot a less than perfect amount of full at the cylinder.  There is no way that there are any contaminates going to get to the fuel injectors so now is the time. 

      Start the beast!!!
     
In conclusion I don?t have many things I would do differently the next time, it will be easier, but isn?t it always!  One thing is for sure, (besides my creative spelling and grotesque use of the English language,) that I will use anther Mattituck FADEC on my next RV, hopefully an RV-8!

      Noel Simmons
      A&P, CFI, builder of fine aircraft
      www.blueskyaviation.net
      1-406-538-6574

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