Oil Cooler and Radiator Mount Bracket

Time: 2.5 hrs

Since I now have almost all the FF parts from TAF I was able to put together the mounting bracket for the oil cooler and radiator. This is the newer way the coolers are mounted to the lower cowling. The old way was a plate and cams type of mount.

After cleaning and demurring I alodined the parts so they hold up a little better. It would have been much easier to put this together except TAF didn’t drill the rivet holds for the radiator bracket to main mount bracket. I don’t know if they did this on purpose thinking that every install might be a little different or if it just slipped by QC. In any case not too had to get the parts in place and drill out the holes.

Everything laid out. I need to add in some padding to the ends of the swivel part that hold the oil cooler down so that it doesn’t get scratched up. I also need to get some camloc receptacles to attach the brackets top the cowling.

Also note I have the UNF fittings on the oil cooler since I’ll be using AN hoses and fittings for the oil lines. I installed these as well and used some Loctite 648 as specified in the Rotax manual.

I had previously cut down some M6 bolts to use as pins for the bottom of the radiator. Today I  ground them down a bit to make them smooth so it’s easier to slide them out when removing the lower cowling.

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Fuel Pump Assembly

Time 2.75 hrs

Well I finally got the parts I ordered from TAF back in December. One of the parts was the 2 plumbing parts that make up the fuel pump assembly. I was originally going to purchase the ones used on the 912 from Rotax, but it seems you can only by the whole fuel pump assembly which is quite costly. I want dto use the Rotax fuel pump box to help protect the pumps a little more then what TAF does with them. The trick is getting all the parts to fit in the box. It’s a very tight fit, but I think it will work. Unfortunately I ordered the wrong check values. I got these from Aircraft Spruce and they’re the 3/8″ hose barb, but I needed 5/16″ hose barb which I have to get directly from Andair (in England). I hope it doesn’t;t take too long for the parts to get here.

The check valves need to squeeze in on the sides. The bottom manifold is a bit wide so that’s the main issue with the space. I wish they made it about 1/4″ narrower, but I guess they weren’t thinking it all had to fit in this box. At least height wise it fits. I was almost going to not even try to put it together since upon first look it really didn’t seem like it was all going to fit. I don’t know if there’s a better way to do the in and out of the pump assembly. I’d rather just have an AN fitting there and not the hoses, but I think that’s the best I can do unless I want to have someone solder on a fitting.

Oil Lines Fitting

Time: 1hr

I had ordered some stainless steel oil lines from Aircraft Speciality which arrived today. I did a quick test fit and everything seems to fit well. I had them not do one fitting on the two hoses that attach to the oil cooler since those need to be clocked exactly. Now I can just set the clocking and ship them back for them to finish up the hoses.There are a total of 5 -8AN oil lines when using the oil thermostat. There is one smaller line that runs from the oil pump to the oil tank which is the oil return for the turbo. I decided to use a flourosilicone hose for that (which hasn’t arrived yet). The rest of the lines are all teflon with stainless steel braid. I also had them put a little fire sleeve on the line that runs near the turbo. I will also put some thermo warp on it so it will cover the orange fire sleeve… hate that orange firesleeve :-).

Most of the lines are visible in this photo. There the run from the oil tank to the thermostat, from the thermostat to the oil cooler, from the thermostat down to the oil pump (in the front of engine), and from the oil sump (on the bottom of the engine) to the oil tank. I’ll get more photos when I install the oil lines later.

The line that runs from the oil cooler to the thermostat on the left side gets pretty close to hitting the upper cowling. I’ll need to tie it down to the alternator in some way.The red tape is where it will need to be tied down.

GEA24 and Other Wiring

Time: 8hrs

Over the past few days I’ve been doing some wiring while waiting for the parts from TAF and the hoses from Aircraft Specialty. I’m not done with the work I wanted to get done, but I figured I should post the progress since I haven’t posted in a while. I’ll be using the Garmin G3X so the Engine Management System module that is used with that is the GEA24. There is also an older GSU73 EMS that incorporates the ADHARS and a few other components, but the GEA24 seems to be more of the standard now. The wiring of the GEA24 is fairly straight forward, there are a few instances where some extra electronic components are needed. One connection is the Tach (RPM) input from the Rotax trigger coil and also a resistor need for the oil pressure sensors. There is a Garmin kit #011-02348-00 which contains all fo the these miscellaneous diodes and resistors, but it’s a bit hard to find. I did manage to find it on a site called Gardner Lowe Aviation Services so I’m hoping that works out. The kit also comes with the more encompassing Garmin Rotax Sensor kit, but I didn’t buy that since there were components that I wasn’t going to use from that. If all else fails I’ll buy the components separately.

One point of confusion for me was how to wire up the temperature sensors. Rotax provides the oil and cylinder/water temperature sensors (I added the airbox sensor). These are essentially VDO resistive sensors, they have one wired connection and ground themselves to the engine block. I did a little looking and found that the RV12 which uses the Rotax 912 uses a single conductor out to the sensor. I saw at TAF (and confirmed with a few other builders) that they ran a 2 conductor shielded wire out to each sensor. One conductor connects to the sensor and the other to the engine block close to the sensor. I also asked Garmin and they said that the “LO” pin needs to be grounded, however from the RV G3X wiring diagram this isn’t the case and even if the pin needs to be grounded grounding back to the main ground block should be sufficient since the main ground block also connect to the engine block. Now having multiple grounds out to each sensor does provide some redundancy which is nice, but it could also cause some potential ground loops. In the end I decided to follow the RV way and not ground the “LO” pin at all. If the sensors don’t work I can pretty easily run a ground from the 4 “LO” pins (one for each temp sensor) to the main ground block.

I also did quite a bit of organizing and clean up of the other fuselage cable runs. I needed to cut back the cable sleeves and permanently label the wire bundles. Grounds will run back to the main ground block on the inside of the firewall. I installed some wire tie brackets to run cables along the top rib. Additionally I made some brackets that I attached to the support which I used to bot a few adel clamps onto so that the cable can run up and out of the center console area without fear of having it rub on any metal edges.

Edge grommet installed for all the sensor wires to pass through the top rib. The GEA24 will be mounted to the right of the hole. I left a bit of wire as a service loop so it’s easier to work on the connectors.

The GEA24 connectors mostly wired up. I’ll need to finish up the RPM and oil pressure wiring once I get the Garmin kit.

I didn’t realize how blurry this photo was until now. I’ll have to retake it tomorrow. This photo has the GEA24 connectors pretty much done with the inexpensive Chinese knock-off GEA24 installed :-). I cut back the wire sleeves on all the cables and labeled them. The grounds are run through the center hole in the top rib (Need to install edge grommet). Now that the cable is all organized it doesn’t feel so daunting of a task to wire everything up.  I’ll need to purchase a few of the avionics that get mounted on the top rib now (GEA24, TCW battery backup, and the VPX)

Nothing Exciting

Time: 1.0 hr

Nothing exciting done on the plane today. I installed the -8AN to NPT stainless steel fittings into the oil thermostat and measured the hoses for the oil lines. There are 5 -8AN hoses that are needed for the oil lines and so I’m having Steve at Aircraft Speciality make those up. There is also one smaller hose that runs from the oil pump back to the oil tank for the turbo, for that I order a length of fluorosilicone hose from Viper Performance Hoses. Fluorosilicone is silicone, but it is rated to be used with oil and fuel so it should work well. The reason I went with regular hose is because the fittings on both ends is hose barb and it will just be a bit easier to use hose with clamps for this one connection rather than trying to replace the fittings with AN style fittings. But maybe I’ll change my mind will have to see when the hose arrives.

Coolant Hoses

Time: 1.5 hrs

I ran the two coolant hoses to the radiator. The left side may be cut back more once I get the exhaust installed and see if there is a way to anchor the hose to the exhaust. The left side also involved using and 45 degree hose since the angle was a bit too much for the super flexible hose that I’m using. On the right side I was able to directly connect the hose to the radiator since the hose was at a good angle to connect to it. The hose I’m using is really flexible and is made from silicone. It meets the requirements in the Rotax manual and  seems to be very high quality hose. I’m really impressed with how well the hose is able to bend and not collapse. I put some thermal sleeve on the parts of the coolant hoses that run near the exhaust. The exhaust is also wrapped so hopefully it won’t get too hot. The sleeve looks a bit nicer then the thermal wrap, but it’s kind of a pain to put on and if the hose bends then it’s even harder. If I did this again I’d probably do the wrap rather than the sleeve.

Photo of the right side hose. I was able to run it directly to the radiator without having to use a 45 or 60 bent hose. I anchored it to the clamp that holds the large air intake to the turbo using an M5 nut and a bit modified adel clamp. I modified a longer adel clamp by cutting it a bit shorter and drilling a new mounting hole on one end. I suppose I could have just bought a larger clamp, but I had a large clamp that I wasn’t going to use. The clamp helps keep the hose a bit farther from the exhaust and provides some strain relief on the connection to the radiator.

The left side hose is quite a bit longer than the right and I had to use a 45 bent hose to connect it to the radiator. I’ll probably end up cutting this hose a little shorter once I see where I can anchor it. I have one anchor on the vertical portion using two adel clamps tied to the white engine mount. Note: I’m going to redo the clear tubing for the overflows with a Y fitting instead of the T to get a better downward flow.

Photo of the join to the 45 degree bent hose. The join is made by using a short piece of aluminum tubing that fits inside of the silicone hose.

Misc Work

Time: 1.5 hrs

Just did a few miscellaneous things today:

  • Drilled 6mm holes for radiator
  • Added neoprene around edge of radiator mount
  • Fixed hinge on rear seat (I had it backwards)
  • Filled/sanded some rivets
  • Fixed small crack in nose wheel pant

I really need to get the parts from TAF that I order back in December. Once I get those I can finish up a lot of the engine items. I’m also waiting on the oil cooler from California Power Systems.

Added some neoprene to the edge of the radiator mount hole. Also drilled the holes for the M6 bolts.

Cut down some M6 bolts and screwed them into the radiator. The new radiator has rounded ends and the cowling seems to have been updated to fit the new radiator.

I’m wondering how difficult it’s going to be to get the lower cowling off/on with the radiator and oil cooler mounted. There will be a bracket that connects the two and then some camlocs will hold them to the cowling along with the 2 M6 bolt pins (above). It seems like it will be a bit of a challenge to get all the lined up when putting on the cowling.