TIme: 6.75 hrs
Over the past week or so I worked on getting the engine finished up. I’m sure I’ll still have a few things to do on the engine, but I wanted to get as much finalized as possible so I can move onto other things. There’s just too many open projects going on at once and I’m starting to lose track of where things are at when I come back to them.
I took a bunch of photos so I’ll just describe what I did after each of the photos. I know I still have a few pending things firewall forward but the bulk of the engine work should be finished. Items remaining are:
- Purchase and install EarthX battery – I don’t want to by this too soon since it will just need to be charged periodically and should be pretty easy to wire up.
- Adjust alternator belt, torque bolts and safety wire – I need to get the prop installed before doing this
- Finalize the throttle and choke cables – I need to wait until the panel is installed or I at least have a good idea where the choke knob will be mounted so that I can cut the cable to the correct length.
I installed the External and Internal Alternator fuses in the engine compartment. I know some people have used circuit breakers in the cockpit, but I didn’t like the idea of running long high current wires unfused and if the breakers were to blow you’re not really supposed to reset it anyways so I decided I’d just put them closer to the source. I also uses a braided ground strap rather than just a wire. It’s easier to see if it’s broken.
Here’s what I ended up doing for the left side coolant hose. NOTE: I should get a picture of the bracket that’s mounted to the exhaust. In any case the hose is supported by a bracket that mounts on the exhaust and then attaches to that using an M8 bolt through the adel clamp. I used a very flexible silicone hose for the coolant hoses. For this side I had to also fit a 60º bend to this main hose since I wasn’t able to get this main hose to bend that tight into the radiator.
You can also see I wrapped the exhaust which I found a few other people doing and one of the guys at Torrance TAF had said was good to do. And you can also see the EGT sensor which I only ran to the rear mounting holes on each side. I had read that doing all four is not really necessary.
I ended up replacing all the nylon locking nuts for the engine mount with all metal locking nuts. I also did this for all the various clamps, etc. You’re not supposed to use nylon locking nuts firewall forward, though I see a few on the Rotax engine (from the manufacturer) so I would expect they should hold up OK.
Just a overview photo of the wiring routing and fuel lines in/out of the fuel regulator.
I’m using silicone and stainless steel teflon hoses so that I have minimal hose replacement when I have to do the 5 year rubber swap outs. The only rubber hoses left are what’s on the engine and in the fuel pump assembly. When that time comes I’ll try to replace those with appropriate non rubber hoses. The one silicone oil hose (connected to the oil tank) is special and is fluorosilicone lined to hold up the the oil.
I used adel clamps to hold the oil and fuel drain lines… kind of overkill I guess. I also combined the left and right side fuel drains so I only have one hose fuel drain exiting the cowling. I still need to cut the drain line hoses a bit shorter.
Another overview photo. I made a few short clamp extensions from stainless steel sheet. One was used to connect the 2 adel clamps for the main oil line that runs from the oil tank to the thermostat. The other connects the 2 adel clamps that are used to hold the fuel line from the fuel flow sensor to the right carb. I also made a bracket to hold the fuel flow sensor.
I ended up running both the oil lines between the thermostat and the oil cooler on the right side. There was just no good place to secure the hose if I ran it on the left side and it comes very close to hitting the cowling and alternator.
Just a shot of the rear portion of the engine. You can see the red wire that runs to the starter and quite a few adel clamps that were used.
UPDATE (09/05/2019): Adding below photos that I forgot to take and some more info.
I was able to get the extension loom from Air Master for about $100 with DHL shipping. This is an extension cable so there are connectors on both ends and Martin (at Air Master) said to leave about 20″ from where the slip ring will be installed which on the Rotax 914 in the center of the engine on the top where I believe the vacuum pump is mounted if you had that option. Having this cable allowed me to close up the firewall for where all the cabling goes through. It’s made from 2 pieces of 1/16″ stainless steel that screw onto the firewall there are grommets also in there for the cables to pass through. Then I put the stainless steel grommet guards on.
Here’s what I ended up doing for the left side cooling hose. I purchased a stainless steel exhaust hanger (9″ JEGS 309002) from Amazon and bent it at around the first hole. I also purchased a stainless steel 1.5″ U clamp to clamp the bracket to the exhaust. It seem pretty sturdy so should work well. This keeps the cool hose away from the exhaust manifold and secures it from moving around.
I didn’t have a photo of how I did the fuel flow sensor. I made a bracket to mount it to the same mounting holes as one of the engine sensors. The hose coming off the regulator is split and feeds the flow sensor and will also the pressure sensor which is mounted on a plate on the engine mount. My only worry is that the 90º bend it pretty close to the inlet of the sensor and the Red Cube manual said not to do that. I spoke to a few people about it and they think that because I’m only pulling 5 gallons an hour it shouldn’t matter, it might matter with a higher volume of fuel since the bend can create some turbulence in the flow and mess up the sensor readings. If I get inaccurate readings I have an alternate idea of how to run the hose so will have to see.
On the ride side of the engine it’s a tight fit for the exhaust manifold, cooling hose and oil line. I probably should add something to hold the oil hose to the cooling hose to keep it from touching the exhaust.My other worry is that the box that goes around the air filter will hit the cooling hose so I’ll have to move it… will have to wait to see when I get the air box.