Engine Install

Today I installed the “red cube” (fuel flow transducer), various cushion clamps, the wiring for the starter, and the alternator.

The red cube was installed per the plans on top of the exhaust. Some people have reported issues with the heat effecting the transducer, relocating to the engine mount. I decided to stick with the vans plans and hope for the best.

There are many cushion clamps needed in the engine compartment, and I installed a bunch of them. Most of the clamps are arranged in a pair, where one clamps to the engine mount, and the other attaches to the wiring that needs supporting. They are joined together with a bolt. others mount to the engine itself, and these require removing a bolt or screw, and then reinstalling with the clamp in the washer stack. In two places on either side of the crank case, the bolts are too short to install the clamp, and I’ll need to buy some longer bolts. I’ve put a reminder on the engine so I can buy some later.

Then I moved onto the wiring for the starter, which was simply installing the wires into some of the clamps, connecting them to the starter motor, and installing some boots.

With that done I installed the alternator. This was fairly easy, but I couldn’t find my .041 stainless safety wire so I couldn’t finish the job. Everything is finger tight right now, and I’ll torque it down and safely wire once my shipment comes in.

Last night and tonight I worked on installing various engine fittings, and made the bracket for the fuel flow transducer bracket.

I had been exchanging emails with Vans over the fuel pump overflow fitting. The brass sleeve they sent me didn’t fit, so I ordered a nylon one from Aircraft Spruce and that worked nicely.

Tonight I torqued the engine mount bolts to 43 foot pounds, installed the ground strap, and replaced the cotter pins in the rudder pedals after bleeding the brakes. I torque sealed all of the engine bolts.

Today my friend Simon came over and we hung the engine on the airplane! It was a big day, and it all went according to plan.

I borrowed an engine hoist from my neighbor, and it worked out well. The engine was still encased in its foam shipping crate, and was sitting on a 4×8 foot dolly I had built with wheels. That allowed us to roll everything around and position things easily. Before we started, I printed and studied the document here which is very helpful. I copied the Vans diagram from the plans and taped it to the side of the plane. I arranged the hardware in a cardboard box to ensure we had the right bolts, washers, and orientation on the rubber mounts for each bolt.

I also leveled the plane by raising the tail and resting on a saw-horse. To make sure we didn’t have a balance issue, I slung 40 pounds of weight below the saw-horse, and strapped the plane down onto the horse. Then I chocked the main wheels to keep it all steady.

We started by lifting the engine clear of the packaging, then carefully rolling the engine into position. A little adjustment in height and some side-to-side movement and we had it in the right spot. Following the instructions, we started with the top right bolt, which was fairly easy. The second bolt was the top left, and also fairly easy, as the engine could still be moved around a little. The third bolt was bottom right, and took some more manipulation than the others. The final bolt took the most effort. We tried all options of changing the torque on other bolts, and lifting and lowering the engine, to arrive at the optimal alignment. We were able to get it started into the hole by hand, but had to screw it into the hole to get all the way through. It didn’t take much torque, perhaps a couple of foot pounds at most.

Once all four bolts were in, we torqued up all of the bolts to 40 inch pounds, then disconnected the hoist. I need to check my math on the torque values to get it right, but the hard part is done! It feels like a huge step forward to have the engine on, and that much closer to being a real airplane.

Update, after doing some research, I’m going to torque the bolts to 42 foot pounds. This allows for a couple foot-pounds of torque drag (I measured between 1 and 4 foot-pounds when rotating the bolts), and still being in the target 37.5 to 41.7 range.

Tonight I installed the remaining engine fluid fittinga on the back of the engine, at least those that need to be installed before the engine is hung. The only exception was the fuel pump overflow, where the fitting is on, but the clear tube isn’t. I’m waiting on parts from Vans before I can do that step.

I also installed the ground strap, and the governor and governor bracket, bending the fuel line out of the way, and clocking the governor lever to the right position.

Tonight I made the governor bracket, and test fit the governor. The bracket was trivial, and once it was completed I primed it with some spray can primer. I took the cover off the governor mounting pad, cleaned it up, then test fit the governor. Everything was fine, although I need to buy some lock washers.

Today I installed the sender mount onto the firewall, then I spent time unboxing the engine and installing various fluid fittings.

The sender mount was simple. I elected to keep the third port because I’m going to use the Aircraft Speciality P-Mag mod that uses the third port.

Unboxing the engine was exciting, and a bit messy. I pulled away the cardboard box, and then broke down the foam surrounding the engine. I only went as far as I needed to access the various fluid fittings on the back of the engine. I got most of the fittings installed, hopefully I can finish installing the last couple tomorrow.

Tonight I installed the master relay and started solenoid, wiring it up and torquing all the bolts and nut’s appropriately.

I emailed Vans and on their advice switched from the split washers shipped with these components to stainless internal tooth star washers. They are slightly thinner and allow more threads to show through after torquing the nuts. With the original washers, there were not enough threads showing where WH-P769 attaches to the master relay. With the new washer, it’s still not ideal, but seems ok.

The firewall is starting to look a little more crowded now.

Tonight, after several weeks break, I finally did some more work on the plane. I installed a few components onto the firewall; the manifold pressure sensor, the master relay and starter solenoid. the manifold pressure sensor isn’t actually installed yet, I had to prime the mount, but I located the parts and got them ready to go.

Tonight I installed the battery. Just a couple of steps was all I had time for tonight. I finished fabricating the battery bar, installed it, then installed the little grommet that sits on the side of the box.