Category Archives: Engine

Time: 2 Hours

I needed to run the oil breather tube from my inverted oil separator tank to the bottom of the engine area. Normally with the stock setup it would run from the top/back of the engine case. This tube is required to release high case pressures and allow any excess pressure and/or oil to be expelled overboard. Van’s stock setup comes with a pre-bent tube and hose attachment. Since I went custom I needed to create my own. Not a big deal and I just needed to determine the angles to follow the path I planned. I also needed to get it close to the engine mount so I could secure it and direct the tube just over a section of the exhaust pipes. This allows any oil that is expelled to be burnt off and only create smoke. That’s the idea however I have read that a lot of the oil doesn’t get burnt off and ends up on the belly of the plane for you to clean up. Hopefully the inverted oil system and the separator help prevent this from happening. Here is how mine turned out. I cut the end at a slight angle pointing forward. This is a theory that it creates positive pressure in the tube to help prevent oil from being sucked out if it were angled the opposite way creating a venturi effect. It is very secure once I tightened it at the separator and clamped it above the exhaust. It is clear of all the other hoses except the heater hose. With the bends I made it’s away from the firewall by a 1/4″. I used Aircraft Spruce’s Versatube for this project which wasn’t too terrible to bend and shape using the spring bending tool.

Time: 2 Hours

Another firewall forward wiring task was to finish up the E-Mag runs. This is my engines ignition source. In traditional Lycoming engines they use magnetos to provide the ignition source. The E-Mags use newer technology to control very precisely when the spark is delivered in reference to pistons compression stroke. Another benefit is they have their own internal alternator that provides power for the spark even if all ships power is lost. For these reasons I went with this setup. There are only four wires needed to go to each E-Mag, a 12 volt source, a ground, a p-lead and a digital tach reading. The 12 volt, tach and p-lead I had run a while ago so I just needed to add a ground to the mix. I made the appropriate extensions to the wires and figured the best path to run the wires to the E-Mags. They have a connector that plugs into the back and you just have to screw each of the wires to the connector. The 12 volt source provides power under normal operations, the ground provides normal ground and the tach will give me an RPM reading. The forth wire is the p-lead for testing the function of the E-Mag using a switch in the cockpit. In normal operations the power is providing spark using the ground of the engine with the p-lead switch(I labeled it ignition) in the on position. When you put it in the off position you are grounding the p-lead and denying the E-mag from creating spark which only allows half of the spark plugs to operate making the engine run rough and providing a positive test that the E-Mag is working when the ground is removed. The last test for the E-Mag will be to remove the 12 volt power to make sure the internal alternator operates. I will do this by turning the circuit breaker off on my Dynon screen. After running all the wires I secured them and plugged in the connector. If I did them all correctly when I put power on I should see a red LED followed by a green LED. My luck was good and that’s just what happened!

Time: 2 Hours

I have had the smoke system installed for some time now and is located in the aft cargo area. All the wiring and plumbing was finished all the way to the firewall where it ended in a T fitting. From this T fitting the smoke oil splits into two lines that run to two of the exhaust pipes. Now was a good time to locate and install the spray nozzles and their associated lines to the T fitting. Just like the EGT probes you need to do some measuring and figure out the best spot for your given setup. Once I was happy with where I wanted to placed them I marked and drilled the required 3/8″ hole. Then it was just a matter of running the line and securing it from the T to the exhaust pipe. The spray nozzle is welded to a metal flange that gets secured with two clamps. As a back up the instructions have you safety wire the nozzle as well. I left plenty of slack to account for engine vibration. One more firewall forward task done. The tasks are slowly disappearing!

Time: 2 Hours

Part of the engine instruments is the measurement of the exhaust gas temperature(EGT) and the cylinder head temperature(CHT). These take analog info in the way of a probe that gets heated up and will be converted to a digital signal via the Dynon engine monitoring system(EMS). These signals can then be read in digital form on either of my screens in the instrument panel. For the CHT’s there is a threaded port in all four cylinders that a adapter threads into. Then the probe can easily be inserted with a quarter turn. The exhaust gas probes need a 1/8″ hole drilled into the exhaust pipes somewhere between 2″ – 6″ down from the flange/cylinder. I did some measurements and alignment planning for these so that they won’t interfere with items like the engine cowl. The most important part of the measurement is that all four probes are identical in relation to the distance from the flange so they can be accurately compared to each other’s temp. All eight probes have a length of wire on them and these will get spliced to the EMS wires that I had run a long time ago to the firewall.

Time: 4 Hours

Now that I had the probes all installed I could finalize the wire routing and do the splices. I had a lot of extra wiring from the EMS and just had it curled up on the firewall. I figured out where I want the splices to sit as it needs to be an easily accessible area for future replacements. Ones that was determined I measured and cut each wire to the correct length and began the process of stripping each wire. I decided to use knife splices and cover them with shrink tube to help in the replacement process in the future. The probe wire are interesting as they have a fiber like covering versus the tefzel I was used to. So striping then took a little more time. I used shrink tube to cover the transition of the outer sheath to the exposed wires. Then with the knife spices connected I covered those with shrink tube. Then I covered the entire thing with a large piece of shrink tube to protect it. I organized all the wires and routed/secured them to the engine mount. I left plenty of slack to allow for engine vibration as well. I powered up the Dynon system and tested the probes by putting a heat gun on each one checking to see if the instruments showed a rise. I’m happy to say every one worked perfect. So I repeated the whole process on the opposite side with the same results.