It’s time

to get the firewall on this beast. That is all that is holding up remounting the engine. Which is what is holding up the remainder of engine hook ups like throttle and mixture cable. Which is what is holding up first engine start. This project is a big domino effect, and I can’t wait to until we get to that brick in the chain. So before my vacation, we are trying to get the firewall installed. 

To that end, I needed to determine some locations of components on the firewall. So I put the engine mount on the engine and pinned the engine mount in place on the airframe. 

  

While the engine was next to the airplane, I put the cowl in place. This let me see how the fuel injection servo fit in the cowl as well as the oil cooler. Fuel injection fits well, I need to trim the oil cooler exit duct a little bit yet. So I marked it and will trim it soon. 

  

After I was done checking the fit of the fuel injection and oil cooler, I moved the engine away and got to work. I continued working on the firewall template that Greg was working on the other day. 

There were plenty of holes to drill to match the firewall. I also added two holes for the electrical wire pass throughs. Then it was lunch break and time to go to WipAir to get some parts. While I was at the airport, I ran into Greg. He decided to come pver and spend some time in the Garaggio. 

I handed the firewall template project over to Greg. He kept going with that and made some progress.  Soon enough we will be ready to cut out our firewall. 

 

While he was working on that, I added some bulkhead fittings in the upper firewall. These are for the fuel vent lines. I’m venting he fuel system to the bottom of the airplane, as opposed to the plans. If you vent the fuel tanks to the bottom, expanding fuel doesn’t burp onto the canopy. The vents connect to the bulkhead fittings, then after the firewall is installed, I will add two stainless steel lines that terminate overboard. 

  

I also mounted the manifold for the pressure sensors for the engine. It’s on the upper firewall. It is simply a mounting feature that collocates the sensors and then they get wired to the EFIS. All the pressure references get plumbed to this as well. 

  

Lastly, I made up some parts for the bleed air system. I know, a piston engine airplane with a bleed air system, WTF? The bleed air system is simply a pressure reference for the fuel injection system. The fuel injectors need a pressure reference to properly meter fuel. It’s normally not important and omitted, but I am planning on testing different induction inlets including ram air. For all this testing and different configurations, it will be important. 

So I bent up a 3/8″ aluminum tube, flared the end, and added fittings. I drilled a hole in the induction inlet and found the relative position. I drilled a hole inter bottom of the firewall to make room for the bulkhead fitting for the bleed air system. I will finish this system soon, but for now you can see the fitting protruding through the firewall. 

  

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