Kit Aircraft Modifications

Hi All,

I was out at the airport this morning working on the fuel flow monitoring system in my RV-10. I am not getting any reading on my AFS 4500EE. As you read in the previous post, I have 2 fuel transducers. Today I isolated each of the transducers and fed them directly into the 4500EE. Happily, each of them performed perfectly.

This leads me to the resolver box that is supposed to read each of them and subtract the supply from the return. Maybe I have them wired backwards and the resolved output can’t go below zero? That might lead to the output of zero on the monitor. I will have to run the wires back to identify the individual fuel flow transducers and then look at the resolver box wiring diagram to see if I have the supply and the return connected properly.

Something to look into over the weekend.

Build Smart and Fly Safe

Dave

Hi Everyone,

The LS1 has a fuel rail that requires unused fuel to be returned to the tank. This presents a problem when you compare fuel flow monitoring with the IO-540 set-up. As there is no need to return fuel to the tank with the Lycoming you only need to have one transducer to monitor the flow.

My set-up requires that I monitor the fuel flow in both directions and then subtract the two to determine the usage. I use 2 of the Red cube fuel flow transducers which plug into a resolver box supplied by Advanced Flight Systems. This box takes the signal from the individual sensors and subtracts the supply from the return and sends the resolved signal to the EFIS.

Tomorrow I have to check the installation against my wiring diagram because I am reading 0 flow when the engine is running. Just another in a list of wiring educational challenges I have had to rectify before I can take the plane up in good conscience. Luckily the list is almost completed.

I need to look at a brake line fitting that I am getting a slight seep from and some engine compartment items that need to be completed. I’ll say it will be a week to a month before I have her prepared for flight but you know you can’t hold me to that!

First flight will be on Tuesday!!

Build Smart and Fly Safe

Dave

Hi Everyone,

I received a message from my engine ECM guru Bob at OBD Diagnostics today indicating that he has recently done some work a Velocity with an LS1 in it. It has the same Delphi MEFI-4b ECM in it as is used in my RV-10.

Bob said that he had a look at the tune that was supplied with the unit as purchased from Painless Performance. His assessment was not very good. He felt that the engine was being run too lean and he has since come up with a baseline tune that is better for the engine in the aviation environment.

The whole issue of what ECM is best to run these alternative engines in aircraft has been a controversial discussion topic for years. I have met those who swear by the factory ECM and those who wouldn’t touch one with a ten foot pole. I happen to be in the latter camp and I have one of the Delphi MEFI-4b units in my aircraft.

I chose this unit mostly because of its reputation for robustness. The thing was designed for the marine environment and is pretty bullet proof. It is also small. About one third the size of an OEM unit. I also like the fact that there are tools available to be able to tune the program. Lastly, I like the fact that it is an engine only computer. It is not designed to operate a transmission as well. This reduces programming complexity and any reduction in complexity is welcome when installing a conversion engine in an airplane.

A move is afoot by people flying this LS1 setup to evaluate the new tune. They are taking an instrumented approach and this will lead to a better knowledge of the programming and its interaction with the aviation environment and power requirements.

I have recently received my Certificate of Airworthiness and in the short time before we fly I am assuming that I will be learning how to install a new program in this computer.

Build Smart and Fly Safe!

Dave

Hi Everyone,

I received notice from Geared Drives a while ago that they are suggesting that everyone install separate fuses for each of the ignition coils. Apparently they had an occurrence of a coil shorting out. This in turn caused the fuse that supplies all of the coils to blow and the total loss of power.

Geared Drives suggested that we purchase a Granger fuse holder and 20A fuse for each coil pack.

The Granger unit looks like this:

Here is a photo of the finished installation on my LS1:

It worked out that it is a very neat installation that leaves me lots of room to get at the fuses. Looks “Factory”!

Keep on building but remember to kiss the wife and thank her for letting you have so much fun without her! You don’t want to get AIDS (Aircraft Induced Divorce Syndrome)

Dave

I have been working on the engine wiring harness and have made some progress. I have taken all of the wires and replaced them with Tefzel wire. I have crimped on new terminals at the sensor or device ends. This went very smoothly and I am happy with the result.

I have run all of the wires across the engine compartment and down one of the rails of the engine mount on the co-pilot side. The engine computer is mounted on the co-pilot side of the firewall about mid height. This is where all of the wires run to and get terminated in either of two 32 pin connectors or they go to the ignition relay and power sources.

I am planning to run all of the wires through some sort of protective  sheath so that the heat from the headers is not a problem. I have to get to work on terminating the wires at the computer and get the power supply worked out.

Lots of work ahead.

Dave

Hi Everyone,

I have been working with Ed Hollestelle Jr. in an effort to modify the cowl on my RV-10 so that it will fit over the Geared Drives PSRU.

The whole process of coming up with a new profile on the lower cowl was hugely daunting for me. I would much rather work on aluminum than the fiberglass. I would sit there on my little wheelie chair and stare at the gaping hole in the lower cowl that I had to cut into it to get the lower cowl to fit up around the engine and gearbox. I didn’t have a clue where to start.

I heard about Ed from his father who is a member of the local RAA chapter. Ed works at the Diamond Aircraft factory here in London Ontario and was happy to come over and have a look at my project.

The amazing thing for me was that he had a plan put together in about 5 minutes. I showed him the pieces I had left over from my efforts previous and he incorporated them into what would be the final design.

Basically, I took the upper cowl and made a cut along the feature line that mates to the spinner on the inboard edge of the cheek inlets and sort of moves rearward and converges a few inches from the windshield and cut it out. I did this because I had some interference with the injector fuel rail ends.

The PSRU manufacturer chose to deal with this in his firewall forward kit by using blisters. These fiberglass items can be purchased from Aircraft Spruce and look like they belong on some radial engine cowl. Totally inappropriate for the upper cowl on an RV-10.

With this piece cut out, I basically took a couple of rulers and placed them across the opening. I set the cut out piece on top of the rulers. This gave me the extra room necessary to clear the injector fuel rails. I then foamed the gaps and glassed the unit back together.

The lower cow was a whole different matter. I had to incorporate the new air box I fabricated into the lower cowl design. This air box is mounted to stand offs that are welded to the oil pan. The air box was fabricated to the width of the oil pan and is quite a bit wider than the air scoop that I had removed from the lower cowl.

We decided to reattach the lower ram air scoop and to get it to fit around the new air box we had to cut it down the middle and widen it by 4 inches. This looks great and gives the airplane a much more aggressive look.

I will post a picture here and talk more on this tomorrow.

Dave

Good Morning,

I had my good friend John Goris from Purple Hill Aviation (www.purplehillair.com) over this morning to have a look at my RV-10. We were talking the other day about this wiring harness redo when I was out at his shop. John does all sorts of aircraft maintenance. He works on both certified and non-certified aircraft and has been a great resource to me as I trod along the path to completion of my RV-10 project.

John currently has a Cessna 337 in his shop which is being converted over to have new engines. The owner is installing turbocharged LS7 engines both front and back. It is quite a project. The guy wants to be able to fly it non-stop from Southern Ontario to Cuba. Canada does not have the same flight restrictions going into Cuba as the US does. The kicker here is that we can fly direct to Cuba no problem. We just cant land in the states on the way there!! It has to be a direct flight.

This guy holds the patent on the serpentine belt tensioner and manufactures them for all of the automakers. He has money to play. The 337 has a wing off of a variant used in Vietnam for spotting. The whole wing is a fuel tank practically and he has drop tanks installed on mount points on the wings as well.

Getting back to the wiring harness, John wanted to come over to see how I was progressing in the change over of wiring and to have a look see as to the overall progress I am making.

As an AME he totally agrees that there is a problem with the PVC coated copper wiring used in the OEM wiring harnesses used by alternative engine installers. He looked over my partially complete installation and gave me the thumbs up.

I received the special terminals for the injector connectors from Mouser yesterday an can now go into the garage to finish them up. Once that is complete I can move my Black&Decker workmate over beside the plane and start threading the myriad of wires through the main connectors that attach to the ECM. Once I have them all untangled and cut to the proper length I can get going on attaching the new terminals there.

I have been asked to write an article about this for our local RAA (Recreational Aircraft Association) and I have a feeling that It is going to end up in a couple of magazines like Sport Aviation and the Recreational Flyer. I have taken a bunch of pictures to accompany the article that I will get posted in here eventually.

Have a great Flight!

Dave

Hi Everyone,

I spent most of my free time on the weekend working on the engine wiring harness. After consulting with AC43-13 which is a manual that sets out acceptable methods and practices regarding aircraft construction and repair, I determined that the PVC coated copper wire used in the construction of the engine wiring harness did not meet the standard.

PVC or Poly Vinyl Chloride is the plastic material used to insulate most modern wire used in engine wiring harnesses. The PVC insulation used in engine wiring harness will burn and when it does it gives off a very toxic smoke. Not good if you are in an airplane. The melting point of PVC is around 175 deg F. or 80 deg. C. The conductor is stranded copper which has a propensity to corrode.

Ac 43-13 stipulates that wire manufactured to Specification ML-W-22759/16 be used in aircraft. It features stranded tin-plated copper conductor and is insulated with extruded Tefzel (ethylenefluorbethylene) which has a maximum temperature rating of 302 deg . or 150 deg C. It is also rated for 600 volts.

As you can see, there is a marked difference between the two types of wire. The heat rating is almost twice as high as the PVC and the tinned multi-stranded wire resists corrosion.

So here I was with a wiring harness that I purchased  from Painless Performance that fits the Delphi MEFI 4b ECM that doesn’t have the correct wire. What to do?

Well, I started off by going to talk to my friend who owns a car stereo and alarm installation business. He told me to go to an auto parts wholesale place around the corner and there I could buy all of the terminals I would need to replace the ones in all of the Delphi connectors.

This proved to be an interesting experience. The guy there pulled out a catalog full of about a million different connectors and terminals. I realized that I needed much more information before I went in there to order.

So I came home and looked at each individual connector on the harness I purchased and photographed them. I then took the photographs and the codes on the connectors in to match them to the photos in the catalog.

This worked out pretty well except for the terminals in the connectors that attach to the fuel injectors. These were only available from them as an assembly or pig-tail. This was no good for me as the terminals would have already been crimped and PVC wiring would have been included.

After a little digging and a couple of phone calls I ended up with the actual Delphi part number. With this in hand it was relatively easy to find the part on the internet. I purchased the terminals from Mouser and had them shipped.

For the wire, I went to Aircraft Spruce. They sold me about 500 feet of 18 gauge Tefzel wire in 4 colours for the project.

I was able to locate a pin-out list and diagram on-line through MSD. They sell a comparable computer.This gave me an understanding of all of the wire runs which allowed me to pull all of the pins from the  two 32 pin connectors that attach to the computer.

With this done I could then start to take the old wire out of the plastic connectors which I plan to re-use. I have been able to recreate the individual sensor harnesses and have laid them in place.

I will install the terminals to the wires going to the ECM connectors next.

All of the connections to the terminals that I have made so far have also been soldered at the very front of the wire. I only apply a small dab of solder at the very end of the wire so to keep the rest of the wire within the crimp flexible. Too much will take away the wire’s ability stay flexible. Failure to do so will lead to breakage due to vibration.

This was one of those unexpected jobs that pops up when you don’t expect it. I am glad that I was able to understand the specifications and install the proper wiring in my airplane. I would do it all over again as it is the proper way to do things. It just took a long time to run around and get all of the materials and more time yet actually installing it.

Have a nice flight,

Dave

Good Morning,

Today I am going to talk about the purpose and placement of the fuel regulator for my LS1 fuel supply system.

The LS1 engine I have mounted to my RV-10 requires a fuel supply system that supplies high pressure fuel to a fuel rail connected to the fuel injectors. This ensures a constant supply of 50-60psi fuel at the injector which is only used when the fuel injector is triggered by the ECM.

The fuel system also requires that the fuel flows through this fuel rail and eventually back to the supply tank. At some point in that circuit the pressure needs to be returned to atmospheric and this happens as it goes through the pressure regulator.

The fuel pressure regulator does the same job as your thumb when you put it on the end of an open garden hose. The spring in the regulator applies pressure to some sort of restrictive mechanism the same as you applying pressure to your thumb over the end of the hose. The result in both instances is a rise in pressure in the tube leading to the restriction. The fuel or water as in the hose example returns to atmospheric pressure as it is released through the smaller opening.

In my installation I have the fuel being supplied to the co-pilot side fuel rail where it flows forward on the engine. It gets bridged to the pilot’s side rail via a braided stainless steel flexible fuel line. It then runs aft and exits the fuel rail directly into a pressure regulator. The low pressure fuel is then routed back through the firewall and into the header tank. Any excess fuel is then routed back to the supply tank via the return tank selector valve.

The fuel pressure regulator has a 1/4″ barb fitting coming out of its upper housing that is attached to a vacuum fitting on the intake manifold. There is an adjustment nut on the top of the regulator to vary the pressure according to the engine’s needs.

I am thinking of installing a mechanical fuel pressure gauge in an unused port on the side of the gascolator at least temporarily. I would like to be able verify the actual pressure against the indication I receive from my engine monitor. It will also be useful if I need to adjust the pressure while the high pressure supply pumps are running.

Well, I have pretty much hit on everything I have done regarding the fuel system.

I am going to be working on and documenting the complete re-wiring of the engine wiring harness next.

Dave

Morning,

I am going to talk about fuel lines in the engine compartment and how important it is to have them properly routed and protected from heat sources.

My RV-10 has a fair amount of fuel line running throughout the engine compartment. Along with this line are some pretty significant sources of heat. I have given a great deal of thought to the placement an routing of the fuel lines.

This has been fueled (sorry!) by the knowledge of an incident involving another V8 powered aircraft that had a fuel line failure within the engine compartment. The aircraft was a Wheeler Express and there was very little time to get the aircraft on the ground.

Luckily there were only minor injuries to the two occupants but the aircraft landed in a hay field and was completely consumed by fire.

As a result of this, I have decided that all flexible fuel lines in the engine compartment shall be Teflon lined, braided stainless steel lines with proper aircraft grade AeroQuip fittings. Each line also is covered in high temperature fire sleeve that has had its ends dip sealed in liquid high temp silicone and the ends mechanically fixed with stainless steel band clamps.

I have lines running from  the firewall to a drain valve as mentioned in the header tank drain valve post. I have a line running from the gascolator to the fuel filter. Another, from the fuel filter to the right side fuel rail. A line runs between the fuel rails at the front of the engine and another runs from the fuel pressure regulator back to the firewall to drain into the header tank.

All of he lines have been routed away from the headers which are the primary concern when it comes to heat. I have also tried to make sure that there is adequate cooling air flow over the lines in an attempt to keep the fuel as cool as possible as it moves toward the fuel rails.

This is one area where you want to spend the money and buy the best that you can get. I have my hoses made by the same people who make the replacement hoses for the Air Canada Jazz. This feeder line has a local maintenance facility at the local airport.

Have fun in the shop today,

Dave