Jur's RV7 Aircraft Factory
3497 hours and counting

Worked today on the fuel overflow line.

The fuel pump overflow line is connected to the vent port of the engine-driven mechanical fuel pump on the Superior IO-360. Under normal operating conditions, this line remains dry and does not carry fuel. Its primary purpose is to safely route any fuel overboard in the unlikely event that the fuel pump's internal diaphragm develops a leak.

The mechanical fuel pump contains two diaphragms separated by a vented chamber. If the fuel-side diaphragm fails, fuel escapes through the vent port instead of entering the engine crankcase, where it could dilute the engine oil or create a fire hazard. The overflow line directs this leaking fuel safely beneath the engine cowl, providing a clear visual indication that the fuel pump requires immediate inspection or replacement.

During every pre-flight inspection, the outlet of the overflow line should be checked for signs of fuel staining, blue avgas residue, or active fuel leakage. Any evidence of fuel from this line is abnormal and should be investigated before further flight, as it is an indication of a failing mechanical fuel pump.

Vans sells an overflow plug which screws into the fuel overflow port of the mechanical fuel pump at the rear of the engine.
In the image below, the overflow port is the one I removed the red plug from.The other ports are the in and out flow of fuel in regular operations.

The image below shows the plan how to install the overflow line and an image of the plug that screws into the overflow line on the mechanical fuel pump.

The line passed this piece is a plastic tube which is connected to a 3/16" alu tube that curves around the lower engine mount and spills the excess fuel overboard through a hole in the flange of the firewall.

You should create a small flare on the bottom of this tube plug. Don't overdo it as you won't be able to fit a plastic tube over. The flare prevents the plastic tube from sliding off the tube. Some saftey wire holds the plastic tube onto this.

I needed to find a good exit point on the frewall flanges. The plans don't really give you an indication where this should be. I held the plastic tube down from the fuel pump and tried to determine the best possible routing.
The best spot was to pass the plastic tube in front of the diagonal engine mount tube, down towards the bottom flange of the fuselage.

I used a piece of safety wire which I bent in shape in order to get an idea how the aluminum tube should be shaped.

The best possible exit location was on this skybolt tab. It leads the fuel far enough from the exhaust pipes exit and is as far as I can go with the provided plastic tube by Vans..

Then started shaping the 3/16" tube. Vans plans tell you to put some plastic tube over the aluminum tube and use zip tyraps on the engine mount.
Each time I hear ziptie and engine mount in the same sentence, it gives me the shivers. It's just not a good idea.

Instead I used these 2 adel clamps and secured the aluminum tube in a more aircraft worthy setup.

 Here you can also see the exit below the bottom fuselage.

Looking at it from the side, you can see the line is sufficiently clear from the engine mount. It takes some thinking when applying these bends. The material is thin and allows for easy minor modification by hand.
Don't get too excited doing it by hand. It's also soft enough to flatten out in the bends if you overdo it. I only used the 1/4" tube bender and did only minor adjustments by hand.

Time to install the overflow plug in the mechanical fuel pump.

The fuel pump has an aluminum case. Thightning the overflow plug too much mach cause the case to crack. The note on the packing clearly indicates you should install the plug fingerthight and then add 1.5 tot 2 turns.

Put some fuellube lubricant on the plug. I had this on the shelf for years and never knew what to do with it. Well here is an application for it.

With the plug installed in the fuel pump, I attached the plastic tubing to the plug. Easier said than done. It's actually pretty hard getting the tube more than 1/4" over the tube. 
The plug also doesn't feel like very strong so excessive force is not a good idea.
A little heat from a heat gun will allow you to slide the tube higher and get it to about 1 inch up the tube. I doubt if this will ever be able to release itself.
I even doubt if I ever will be able to get the tube off again if I would need to. It's is rock thight. 

 Also used the same technique to connect the plastic tube on the aluminum tube.
Put a tiny flange on the aly tube and get the plastic tube over it for about 1 inch.

 Vans tells you to safety wire the plastic tube. I wonder if it really makes a difference. No way you can easily get it back off but did it anyway.

Safety wire also applied on the fuel overflow port.

I am very impatient to get the baffles painted and do a final install on the airplane. I have been working for month on the baffles and it becomes time to finalize.

Some weeks back I realized that the ignition wiring passthrough adapter does not come standard with the engine or baffle kit and has to be ordered. So I ordered these Champion SLICK M2375 GROMMET from Aircraft Spruce.

This is a plastic adapter that holds the 2 ignition wires for the top spark plugs and creates a sealed passthrough through the rear baffles.

To be honest, they are a complete rip off and not worth the 48.75$ + shipping + 8% import tax + 21 % vat... oh yeah, I forgot to mention, you need 2 of them...
115 euro for 2 pieces of plastic are ridiculous. I could as well have 3D printed these myself. As usual, with certified aircraft pieces, it's the chicken with golden eggs for the manufacturuer.
Enough of financial frustration and back to work.

The vans baffle installation manual indicates some locations for these. There is not a lot of playroom for the  location on the pilot side. The plans indicate to positions them between the oil cooler and the CB706-A aft baffle. I think this is indeed the besst location so I copied the location. As I have fuel injection lines from the fuel injection spider to the cylinders, I want the ignition wired to enter as high as possible.
I took the pilot aft baffle assembly and located the topmost position on the CB-705A baffle. That's constrainted by the oil cooler brace CB-705B. 

Marked the contour and drilled some pilot holes.

I wanted to be smart and get the most sexy looking ignition wire passthrough ever made;..
Got the step drill out and drilled the holes to match exactly the diameter of the circles in the plastic and then filed back the middle of the 8 to give allow the platic to passthrough.

I can save you an illusion already at this point, forget about all that I just said. I will explain below why.

The plastic wire seal fitted perfectly from the back side... I was such a happy builder.

The look on the inside was phenomenal... a true gold price winner...

Until I attached the harnass to the magneto and tried to pass the cap screws of the igniton wires through the hole I just made.
What did you guess... yes right... the screw is too big to pass through.

Some cursing later.... I cut away the sides of my figure 8 and ended up with an oval shape which allows the screw caps to pass through.

Anyway.. back to seriousness. I unscrewed the plastic cover from the back of the magneto and figures out how to install the wiring harnass to the back of the magneto.
I have another article on magneto section that describes this but in short : the magneto wiring harnass can be mounted on the receptacle holes in 4 directions.
However, the screws attaching thecover to the magneto can only be in one orientation. 

There are 3 screws to attach the magneto. The form a triangle. One of the legs of the triangle has a longer leg than the others.
This means you can only attach the screws in the receptacles in one specific orientation. If you are not in the right rotation/orientation, you will not be able to screw in one of the screws.
Easy peazy once you know

In order to get the orientation without trying, I just put a mark on the top of the cap, take the cap of and see where the long edge of the triangle is and measure the same on the ignition wiring harnass and place the long side in the same direction. 

Here I have cutout the opening on the passenger side for the right magneto.
There is more playground here on moving this along the back wall. The oil dip stick is a bit in the way but you can play with the location. In the end, I decided to go with the Vans Baffle plans and positioned it the way they tell you to do it near the corner.

I only placed it a bit higher due to the fuel injector lines. As you can see I got smarter here and cut it right away in an oval shape.

Looking good, time to try the wires

 Here is how it will more or less look like on final installation with the wiring passing through the seals.

 On the sides of the baffle, the bottom ignition wiries will be held by the cylinder head covers.
In all direction, the length of the ignition wires is sufficient and will allow good routing behind the engine. I might place some additional clamps on the rear baffle to avoid chafing of the lower ignition wires on the rear baffle.

 Here is how the backside routing looks like on the pilot side top wires.

A big day again in my project. Nothing substantially done but I have hung the propellor on the engine prop hub for the first time.
I kind of wanted an idea how everything would fit together and what is delivered by Catto with the propellor, spinner and saber extention.

I have a 4 inch Saber extention, spool type. This is required for the Sam James cowling installation.
It took a couple of tries to find the way to do this but it's pretty self explanatory once you understand things. The spinner is predrilled and cut and the holes in the spinner plate are also made with nutplates installed. This makes it pretty simple.

Short bolts hang the spool to the prop hub behind the starter flywheel. You bolt these in in a star pattern. I am just doing this temporarily so there is no torqueing involved yet. This will come of a zillion of times. The long bolts holding the propellor and everything forward of the spool extentions are very long. The threads also extend quite far through the extension. This is probably for having enough space if an additional weight plate has to be added up front.

Here is a view with the prop bolted on. This is pretty damned cool seeing this a first time.

Front picture.

Milestone day ! 
This is one of those days that you know mark the timeline of building your airplane. The moment you hang the engine in the engine mount.
After many days of thinking about missing any things on the firewall, I came to the conclusion that this is the right moment to hang the engine and move on to the firewall forward work. There are some more things I need to do on the firewall, but it's not possible to be sure about the exact location to drill large holes in the firewall until I can actually evaluate the position with the engine in place. i'm thinking of the mixture and throttle cable and alternate air cable. Other than those, I'm pretty sure everything on the firewall is in place.

The same thinking goes for the rear of the engine case. Make sure the 45° restrictor fitting for the oil pressure is mounted in the engine case prior to hanging the engine. It's almost impossible to install this once the engine is on the engine mount. Mine was already installed by PMM during engine assembly. While you are at it, also install the other oil cooler fittings in the engine case (in and out). These can also be done later but it's easier now.

First step was to remove the safety straps that held the engine to the wood pallet that was used for transport. I want to keep track of how this was done as this engine is a brand new engine that has not yet been on the test bench. When all is ready, I will need to unhook the engine and bring it to PMM Wingservice to have it running on the test bench for a first time. This has the disadvantage of extra work on removing the engine and all connections again and having to do it again after it has been run. On the other hand, the major advantage is that I do not have to worry about corrosion and idle time of the engine as it has not yet been running. The cylinders are as if they would be in a stock location on a bench waiting for an engine. There has been no movement of the cylinder heads on the cylinder walls and everything has an oil film on it as delivered from Superior Air Parts. Whether building takes me another 3 years or just 1, it won't matter. I'm gladly willing to take that extra work knowing there is no pressure.

The engine was protected well on the front and rear crankcase and supported in the front under the front with some wood block supports. I'll have to keep all this in stock so that I can re use it in the same way when I bring the engine back to PMM.

Using the engine hoist, we pulled it up, removed the pallet and moved it over to the front of the airplane. Alain helped me on this task to keep the engine in position. It's best having some extra hands around when you do this as the engine is heavy and the bolts are not always willing to go in as easy as you think it would. 

The last part of the moving is the most critical as you don't want your magneto's or fuel pump to bump into the engine mount. Having one person moving and another one guiding the engine is no luxury.

Also notice I leveled the airplane in flight mode. This is much easier to position the engine than if it would be sitting on all tyres which would require you to position the engine at an angle. This leveled way makes it much easier.

I found some documentation online from someone who did this before and described the process. I studied this carefully and upfront, had a close look at the barry mounts and dyna bolt set. You can read it following this link https://www.myrv14.com/buildlog/20150917/Engine_Hanging.pdf. Vans Aircraft also has some drawings available which are not part of the standard plan set that you receive with the kit. 

Study the plans carefully, the barry mounts have to be positioned so that the engine rests on the compression side in the bottom and the compression side in the back on the top mounts. The compression barry mounts are the ones that have a step in the rubber. The non compression ones don't have the ribble on it and look like plain rubber. If I remember well, the non compression ones also are a little larger. Also take care that the washers are in the correct locations. The barry mounts come with one big washer in the box. It's good to assemble the order of all this before starting to move the engine and have thing prepared well. I colored the position of the large washer red in the picture above.

There are 2 lengths in the dyna bolt kit. 2 x AN7-43A and 2 x AN7-44A. The longer ones go on the bottom side, the shorter ones go on the top. The difference is not much more than the length of one of the washers.

Start with the 2 top bolts. The first one is very easy... tighten the bolt but don't torque it yet, you'll probably have to loosen them again working on the bottom bolts.
You do need to tighten the first so that the barry mounts compress allowing the other hole to come in line with the engine case. Remember this is a dynafocal mount, the bolts point inwards. If the bolt is not tightened enough on one side, it's impossible to insert the second one. As you tighten the bolts, the barry mounts compress and also position themselves in the engine mount. That's important.

What I found very annoying is that you can't put a socket on the bolt head as the engine mount is in the way.  I used an extension on the wrench but that didn't make it easier.

The engine sometimes needs a bit of persuasion to get it in position :) Although I don't think this did much. Found out later it's more important to tigthen the other side and use the engine hoist to lower or lift the engine a bit in order to get a bolt in.

The large washer goes between the compression mount and the crankcase as a spacer for the bottom mounts. On the top mounts, I have put that washer on the compression mounts under the bolt head as you can see in the image below. The image has both top bolts in place and tightened.

From there on, things went less smooth and it took about an hour or 2 before I got the last bolt in so I did not take any more pictures until it was done.

I'll try to describe the further process I took.

As both top bolts were tightened, I lifted the engine a bit using the engine hoist. This allowed me to slip the barry mounts between the case and the engine mount. Don't forget the large washer between the barry cookie and the engine case. Don't forget the compression side of the barry mounts is against the engine for the bottom mounts. Then I lowered the engine again and after some wiggling I was able to put the 3rd bolt in. I did have to loosen the top bolts a bit though. 

The fourth bolt is the most difficult one. Looking with a mirror through the hole there was no way the bolt would go in. After a lot of moving up and down, I finally discovered my problem : the washer between the barry mount and the engine case was not aligned and the pressure on it is high enough that it makes it hard to move it. After lifting the engine a bit and tapping on it, I could get it more or less into place. 
A second trick I used was to take an old bolt which was smaller in size and grind down into a guide pin. Once I could slide that smaller bolt in, I was able to wiggle it around in order to get that washer and the engine hole into alignment. I put some grease on the final bolt shank and finally was able to put it in with only very light tapping of a rubber hammer.

I was feeling relieved as I bolted the final nut on that fourth bolt.

As final step, I torqued the bolts. These are AN7 which take 450 - 500 inch/lbs. I used the middle value of 480 inch/lbs. The engine will still need to come off as mentioned earlier but the position of the engine is very important when installing the cowling so I torqued it to the final value.

Took some pictures of the plane with the engine in place. This surely is a big milestone and is a "feel good" moment during the build.

Happy camper...

As I had some time left, I took out the fuel throttle body. This comes with a plastic spacer.

The orientation of the throttle body was a bit of a mystery at first but soon figured out what side was the throttle lever and which side the mixture. 
In the image below I installed it on the forward horizontal induction air intake at the cold sump of the engine. In the image below, the throttle lever is the gold colored arm.

Finally I covered the intake with some paper and masking tape in order not to get foreign objects entering the engine.

End of a productive day was off course celebrated with Alain with a good strong Belgian HQ beer.