I have been toiling away at getting all of the little things tidied up before flight testing begins. One of the major pains in my posterior has been coolant leaks. I sure know what colour Dex-Cool coolant is!!

The latest manifestation of the problem consists of the pressure in the system blowing coolant through and out the rad cap. After the engine gets to temperature I hear a bit of a POP! and usually smell coolant right away as it gets blown all over the firewall and out the cowl seams near the fresh air vent.

I have traced the problem back to three separate but equally at fault items:

The first is what I see as a potentially defective rad cap. There are 2 seals in this cap. One to maintain the pressure and the other to maintain the seal against the housing. This is what contains the overflow as it travels back and forth between the overflow tank and the coolant pressure tank.

Second, is the coolant pressure tank design itself. This tank was designed a LONG time ago and was installed on top of the radiator. The design is very susceptible to the recirculation of air that resides in the top of the pressure tank back into the return line going to the low pressure side of the radiator.

The last issue was the steam bleed off fittings on the LS1 heads. The heads on the engine sit at a slight incline when the aircraft is on the ground. The heads have 4 ports between them. One at each end of each head. Unfortunately, I was not able to install the pair of fittings that had interconnected steel tubing on the high side of the heads due to interference with an aftermarket intake manifold. This means that the bubbles in the system are congregating at the highest point on each head where the fitting is simply a plug.

I have just re-designed the fittings to accept hose fittings so that all 4 of the vents can flow coolant and trapped air back to the pressure tank on top of the radiator. There it will rise along a newly re-designed sloped roof to the highest point in the system at the rad cap.

I also re-worked the pressure tank so that the outflow from the tank heading back to the radiator is at the back of the tank and at the very lowest point in the tank. It is far away from the fitting where the bubbly coolant from the heads in introduced so that every chance is given for the coolant to be free from air before it returns.

The new tank is being fabricated as I write and I have purchased all of the stuff needed to re-plumb the new tank. I have also purchased a new rad cap that looks like it has the proper gaskets and seals to do the job.

I will get it all back together and let you know how it all works out.

Keep the blue side up!!

Dave

There has been a number of instances of Van’s flap motor quitting as a result of the lubricating grease getting into the motor housing and gumming up the brushes. This causes the motor to fail. Pilots have had the motor fail in all positions. This can be an awkward situation that tends to present itself either in the beginning of your flight or at the end. I think that it would be most dangerous during a missed approach where you need to get the flaps up to achieve a positive rate of climb on the overshoot.

My friend Gary Wilcox just posted a great article on vansairforce.net that shows how to take the motor and linear actuator apart to remove the excess grease. I will re-post his article below.

Build Smart and Fly Safe

Dave

Once again I find my flap motor not wanting to go down, oh well, better than not going up after take off. I had cleaned the shaft of the motor before, but did not fully disassemble the unit to clean it out of grease. So, out to the hanger I go to resolve this issue with hopefully a better result than the last time, it lasted 45 hours. First remove the flap assembly from the plane, hard to see in this pic, but there is quite a bit of grease on the shaft. Some is good, but this was to much.

 Remove the two screws from the top of the motor.

Gently pry off the motor cap.

Pull off center body that has the magnets. You can see on the top of the motor where the brushes contact the shaft, all gummed up with oily goop.

Remove two Allen screws from bottom of housing and remove screw unit.

The larger hole was full of grease, this is what works up into the motor to stop the brushes from working properly. Clean out the excess grease.

Clean off as much grease as you can, but be sure to leave some on the shaft that comes out of the housing and attaches to your flap weldment. Also, there are tiny bearings at each end of the motor, don’t put anything in them to remove the grease in them. Clean off the ends of the brushes and shaft where the brushes touch. I used a light touch with a Scothbrite pad. Assemble the unit, putting a drop of Lock-Tite on the Allen screws (was on them when removed) and be careful not to bend the little springs that hold pressure on the brushes. People have different ways to hold these in when reassembling, I just used my fingers, no big deal. Re-install and test. Mine worked fine. Hopefully, by doing the full grease removal it will last a long time.

Best part, it was only an hour job, start to finish.

This was how I did this fix and in no way am an expert. This info is worth what you paid for it. Use it wisely. Your mileage may vary.

Gary

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

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

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

I recently had the final inspection completed  on my RV-10 and one of the snags surprised me. The inspector was looking at my beautiful Andair fuel caps and asked me whether they were ground bonded to the airframe. I didn’t know so we took a multi-meter and checked to see if there was an electrical connection between the Andair sleeve that gets bonded into the original fuel neck in Van’s wing tank and the wing skin. There wasn’t.

This meant that I had to come up with a way to electrically connect the original neck of the fuel tank and the sleeve that gets bonded in with tank sealant.

What I did to correct this was to  drill a hole in the Skirt of the Andair sleeve big enough to allow a 6-32 machine screw to almost pass through. I then drilled a smaller hole through the skirt of the tank filler neck right behind it. I had to countersink the outer hole so that the screw head would not interfere with the fuel cap. There is not much clearance. I used a tap and carefully started the threads in the Andair sleeve. I then threaded the screw that had been sharpened somewhat through both sleeves.

All of this had to be done carefully in order to keep any contaminants out of the fuel tank. I accomplished this by taking strips of masking tape and looping them down into the tank fill opening and just leaving the area exposed where I drilled the hole. When I finished I vacuumed out the hole and checked inside for filings. Anything that landed on the empty tank bottom was removed with a stick that had tape affixed to it sticky side out.

I tested the new configuration for continuity and found that electricity flowed from the inner sleeve to the wing skin. For all of the thinking it took to come up with a workable fix, it took only 10 minutes to actually perform the work.

The interesting thing about this problem is that Andair knows about it but couldn’t offer any suggestions as to a fix. I hope that this helps anyone else who has these fuel caps.

Keep on building,

Dave

I just came across a new flight planning site that has been developed by Canadians and is Canadian at its core. It is called World Flight Planner.

www.worldflightplanner.com

What a refreshing change. It seems that all of the products that I have been reviewing lately in anticipation of flying my plane think that Canada is only 100 miles from North to South! It is frustrating to see all of these wonderful tools in the hands of the Americans and we are left in the cold up here with our whiz wheels!!

EH to GO Doug and Blake!! You have made one Canadian VERY Happy.

Dave

I found this mod in the back pages of  Doug Reeves’ site www.vansairforce.net

Paul Grey from Alabama came up with an arm rest for his RV-7 that is functional and nice looking. I have clipped his caption to explain the photos.

Dave

Hi all, Hope everyone had a good Christmas. Thought I’d post a couple pictures of my cockpit… er… the evolution on the cockpit. The cockpit was pretty much done then I decided I wanted an arm rest. This is what I came up with. Super simple and cheap. You’ll see I also moved the elevator trim knob to just under the armrest. The reason I moved it was because if I was in the seat with shoulder harnesses on, I really could not reach the knob without loosing the shoulder straps. Now, the only thing in the cockpit I can’t reach without loosening the straps is the fuel tank selector. The armrest is perfect as it places my hand right at the throttle. Very comfy. Reaching the trim knob, (and the aileron trim), is just a matter of coming at it from the passenger side of the armrest. Both are easily reached without loosening any shoulder straps.

Cockpit Before Mod

Arm Rest Frame

Arm Rest Attached to Flap Cover

Covered with trim knob moved

Finished Arm Rest

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 hope that everyone had a wonderful holiday!

I have an airplane that doesn’t have a small window for the pilot to open and shout “CLEAR” out of when starting the engine. When it is cold out you want that door shut and with its gull wing design you cant leave it raised with the engine running.

Initially, I thought that it would be neat to have a small powered PA speaker mounted in the engine compartment through which you could broadcast your “CLEAR” at the appropriate time. It would be somehow linked into the audio panel and your headset microphone. This idea proved to be more trouble than it solved.

I then got the idea of installing a small car horn in the engine compartment so that you could warn a larger area with the touch of a button while keeping the doors closed.

I wired it such that the horn circuit is energized only when the starter button is energized. This would keep inadvertent activation to a minimum.

I works very well except for the cheapness of the horn I purchased. It doesn’t sound very authoritative. I guess I will have to be on the lookout for a different horn.

Happy Building,

Dave