On the engine side of the firewall, the fuel line runs from the bulkhead fitting to the fuel filter. We thought about mounting the fuel filter with adel clamps. But that not an… optimal approach. So we fabricated a mounting bracket using blue foam.

Here’s the fuel filter bracket after curing and cleaned up.

Test fit with a filter.

Slots are cut for the clamps

With the filter and clamped into place.

And mounted into position.

On the engine side of the firewall, after the fuel filter comes the electric boost pump. Like the fuel filter, the boost pump requires a mounting bracket. Malcolm has a mold for a Wheldon pump that is almost a perfect fit for my Dukes pump.

After making the mold, the fuel filter was removed so that both mounting brackets could be painted. While they were off, Malcolm applied intumescent caulk around the edge of the titanium.

Once the paint and caulk has dried, the fuel filter and pump are installed along with the fuel lines.

Bulkhead fitting on the right, then the fuel filter and then the electric boost pump. The yellow around the firewall and the motor mounts is the caulk.

We tried to put a flex line between the fuel filter and pump. That way it would be easier to service the filter. But we couldn’t get a flex line to fit.

After the engine was installed we discovered that the upper cowling was hitting the engine in a couple of places.

This is the number 5 cylinder intake tube. It’s hard to see, but it is in contact with the inside of the upper cowling.

There is also contact on the number 6 cylinder intake tube and the main intake port.

Now there are three ways to fix this.
1) Lower the engine. I don’t like this approach. When installing the engine, the airframe is leveled, the engine is leveled and engine location is determined based on the location of the prop in the opening of the cowling. I could shim the top of the engine mount, but that would change the thrust vector. It would also require modifying the cowling to accommodate the new location of the prop.

2) Create “bumps” in the cowling. This is done fairly often. Especially when using non-standard engines or engines with turbo-chargers and intercoolers. The cowling mod can be done over a large enough area so that it’s not too unsightly, so I’m going to call this “plan B” for the intake tubes. It will, however be” plan A” for the main air intake.

3) Modify the intake tubes. This is a tricky approach. This engine has what is called a “balanced induction”. Which means (among other things) that all the intake tubes are the same length. One of the ways these tubes are modified is by cutting off the part that’s too high and welding a flat plate over it. I don’t like this method because you’re drastically reducing the size of the tube which means that you’ll be changing the volume of air that can get to the cylinder.

What I’m thinking of is to change the routing of the tube. By my calculations, the length of the tube will be about 3/4″ shorter after the modification. That makes it “plan A”.

The first step is to find someone who can do it. I searched and found a company that has made a whole set of tubes for a low-profile installation. But they haven’t made any for quite a while and they’re expensive.  After exchanging emails with them I got the impression that they weren’t very interested.

I trolled around the Lancair forums (they run the same engine) and had no luck there. Then I found out the company that made the low-profile tubes were done for the Venture Questair. This basically a propeller driven rocketship. Very small (2 people) and very fast (300 knots). So I started trolling the Questair forums. No luck there either.

Then something interesting happened. I decided to sell the small 2-1/4″ backup instruments I had got from Albert. I put them on Ebay and everything but the airspeed indicator sold (not many experimental aircraft need a 400kt airspeed indicator). But one of the bidders asked if I was interested in selling even though he didn’t meet the reserve. I decided to left him have it. Turns out he has a… Questair! I told him what I was trying to do and he put me in touch with a guy that’s done a few intake modifications.

So now I have to come up with a plan of attack. The first thing I did was to build a jig. I figure the guy doing the mod won’t have an engine handy and he’ll need to know if it’s going to fit.

This way he’ll be able to see if the tube ends will be in the correct location. Then I created a template that shows the shape (or outline) of the tube from two dimensions. You can see where I’ve already done that on the picture above.

Next, using the side view I identified where the cowling was and determined where to make the cuts.

This will lower the profile so it doesn’t hit the cowling. A straight piece will then be added to compensate for the loss of run length.

To test this, I need to build a mock up of the intake tube. So I got some 1-1/2″ PVC and built a duplicate tube.

Then marked the locations of the cuts.

Made the cuts.

Cleaned up the ends and attached.

Then I made a cut on the straight portion and added a piece about 1-3/16″ long.

The final product.

On the jig.

And this is the number 6 cylinder intake tube and the PVC mock-up.

The ends align and based on measurements, it should clear the cowling, cylinders and other hardware on the engine. But the only way to know for sure is to send it down to Malcolm and see how looks in the engine.

Since all the rigid fuel lines are in place, we moved on to the flex lines. At this point, we’ve got the boost pump to mechanical pump line and the vapor return line installed.

The fuel line is the long one that comes from the bottom of the firewall and loops up to the middle of the engine. The return line comes out of the rear of the engine and attaches to the bulkhead fitting on the firewall.

I would direct you to a previous post on modifying two of the intake tubes.

After much work and head scratching on how to modify the existing tubes, we hit a stroke of luck.

The tenets in one of the spaces where Malcolm has his shop became available. For a while it was empty. Then someone moved in. One day Malcolm met the neighbors and during the introductions found out the guy builds race cars. He was showing Allan (of Allan Pittman Race Cars) what we were trying to do and he said basically said “That? I can weld up one those from scratch.”  Well, I guess when you build cars that hit almost 200MPH in an 1/8th of a mile, this is child’s play. I also learned that when the cars go REAL fast… They only need an eighth of a mile.

So I bought the flanges and some stock tubing and gave him the parts. In about as long as it takes one of his cars to fly down the 1/8 mile strip, I had a pair of custom made intake tubes.

Custom intake tubes for the #5 and #6 cylinders

And here’s a before/after of the #5

And of the #6 cylinder

I picked up some “Continental Gold” paint and Malcolm is going to sand blast and paint them.

Then it’s time to modify the upper cowling to accommodate the main air intake. There’s simply no way around that.

Malcolm sand blasted, painted and installed the new intake tubes for the #5 and 6 cylinders.

The paint is not a perfect match, but it’s pretty close. If it bugs me too much, I may pull the front 4 tubes and paint them as well.

I have been dreading pulling the engine control cables from the front of the cabin through the left wiring duct to the back of the plane. After we got the oil lines installed and pulled the brake lines, it just started looking like getting the engine control cables through was going to be a problem.

So me and my son Steve spent about an hour trying different things and finally got all three control cables through.

Here’s a picture on the engine controls on the permanently mounted “Engine Control Sub-Panel” (another Hangar 18 innovation).

A view from the side.

Where they exit at the firewall.

The factory supplied “Engine Installation Kit” comes with a number of pre-fabricated parts. One of those is the bracket that mounts the mixture cable.

Here’s what the factory supplied bracket looks like.

But when I tried to install it on the engine, the mounting holes lined up properly, but the plate was hitting in a couple places. I thought that I might have it installed backwards or in the wrong location but according to the manual, it was in the right place. So why isn’t it fitting? The mounting bracket is for a Continental IO-550N and that’s the engine I’ve got. So I must be doing something wrong. After scratching my head and trying different approaches, I finally decided to modify the bracket. Here’s what I ended up with:

And it fits perfectly. It would be SO MUCH EASIER if the manual just said “this part will require modification to clear existing nuts, bolt and other obstructions.” But no… you gotta figure that out on your own. 🙁

Here’s the bracket installed.

Clears all the obstructions, but it looks… wrong.

Back when I had the intake tubes built, I purchased some Continental Gold engine paint. See where this is going? 😉

Much nicer!

Once the Mixture Control Bracket was installed, I moved on to the prop control. This one looked to be a bit easier. It’s just an “L” shaped piece of aluminum with pre-drilled holes to mount it to the engine. Which means that all I need to do is located and drill the holes for the prop cable clamp.

Except that when I tried to put the bolt through the hole to mount the bracket to the engine, the bolt didn’t fit in the hole. By this point, I didn’t waste any time thinking about it, I just enlarged the holes to accommodate the bolts. Once that was done I mounted the bracket and determined where the holes for the cable clamps would go then drilled those.

Here’s the bracket with the cable mounted looking from the side, bottom and rear.

But, of course, I don’t like the silver aluminum color so it gets painted too.

Next is the throttle control. And that one looks like it will be a real pain. 🙁

I had already done a little checking and I could not get the throttle control cable bracket to fit. I tried a couple different approaches but it just wouldn’t fit. So I started modifying it (much like I did with the mixture control bracket).  Put it on, see where it hits, take it off, file some material away, put it back on. And repeat, repeat, repeat. 🙁

After about TWO HOURS, I threw in the towel and got a piece of aluminum angle. After about 90 minutes, I had a bracket.

On the top is the factory bracket. The bottom is the one I made.

At first glance, it would appear that I could have accomplished this by simply taking off more material. But the problem was where the cable clamp mounted. Those are the holes in the second picture. The first problem was that the bracket was too wide and hit the intake manifold. I couldn’t take any more material away or I would compromise the hole for the clamp. The second problem was the cable wasn’t aligning with the throttle arm. Which meant the cable (and clamp) had to be moved outboard. Hence the new bracket.

I’m not painting this bracket until I locate where the landing gear warning switch goes.