SonexBuilders.net

Hi All,

I wanted to share my enthusiasm at a successful first engine start! It was a great milestone and a big motivator on the way to first flight, given all of the fiddly and slow systems work that's required towards the end of your airplane build... My wife was perhaps the most-stoked, given her "enthusiastic" choice of words when the engine started up. :-) Also, the Turbo sounds really nice at idle.

Readers of the forums will know that I had a couple of parts issues while building my AeroVee Turbo, but with those straightened out the engine went together smoothly. After delaying the engine start for a few months, in order to get the airframe closer to first flight, I finally got her running this morning. Everything is put together per the plans/instructions from Sonex & AeroConversions, with these minor exceptions:

• I used engine assembly lube instead of white lithium grease for much of the build
• I have a vernier mixture control from Aircraft Spruce
• I have no Gascolator and a Red Cube for fuel-flow. The cube is mounted on the "hot" side of the firewall, with just a couple of inches of braided hose between the cube and the AeroInjector. In fuel-flow tests the red cube is reading within 1gph of my stopwatch-calculated fuel flow.
• I've used braided hose for fuel and oil lines in every possible location except for [a] the crankcase breather tube and [b] the oil line from the oil-pressure-sensor to the bulkhead fitting at the rear flange of the engine case. In both cases I used hard line (per the plans).
• I have a B&C Specialty (i.e. Bob Nuckolls) Crowbar Overvoltage protection circuit kit wired in-between the alternator and the main bus
• When I added the oil, I deviated from plans by filling the spin-on oil filter first (which was slow and took some effort to get the air/bubbles out). Then I followed all of the normal instructions. Then I pulled the prop slowly through several revolutions by hand (after checking that everything was off). Then I used the starter motor to turn the engine (again with mags and fuel confirmed off) until I saw ~20 psi of oil pressure register on my EFIS. Then I cleaned the oil-fill area inside the engine case so that I could see when the oil-return line was spitting oil back into the crankcase (after the secondary oil pump). Finally, I cranked the engine for 10-20 seconds at a time, with 3-5 minute breaks in-between, until I verified that the oil return line from the secondary oil pump was spitting oil back into the oil-fill area (Note: Oil cap was on during cranking, then opened up to inspect between runs). Once I saw oil returning to the case I let everything settle for 10 minutes, then I ensured the dipstick was showing "full".

I did run into a couple of minor issues/hiccups today - though none of them were super-serious:

• The first time the exhaust wrap got hot, it smoked a little and that caused a bit of panic from onlookers. In my haste to shut the engine down, I yanked the mixture control hard enough to pull it right out of the aeroinjector control-arm... Whoops! Gotta make sure that set-screw is appropriately tightened, even when some force is applied to the mixture knob. :-P
• I had no RPM readings on my EFIS. I tracked this down later on: The outside terminals are not polarized for the purposes of hooking up the alternator, but only one of the two outside terminals seems to work for relaying pulses to the EFIS!
• My oil pressure gauge was sometimes showing pretty high pressures. Some of this was undoubtedly because it was 42-degrees during the engine run and my oil never got very hot. However, I realized later that my EFIS was set up to expect readings from a 100-psi pressure gauge while the VDO unit maxes out at 80-psi. Changing the scale on the EFIS should give me more-reasonable/more-accurate pressure readings.
• My oil temp gauge seems to have a "dead band" between 32 degrees and ~70 degrees (and I checked this using a space heater while the engine was stopped). I'm still not sure about this issue, it could be one of several things: It could be a bad probe, it could be the way the EFIS interprets when the probe is "off-scale low", or it could be that the teflon paste I used as thread sealant (or the anodized cover-plate itself) is preventing the probe from getting a good/consistent ground.

Hope this info helps and is encouraging to others who're looking ahead to the completion of their projects!

--Noel
Sonex #1339

Congrats, engine and cheers sounds great.

Great job....congrats ;)

Excellent news Noel! Congratulations!

Awesome!

Great to hear Noel!

Congratulations on the first start, a major milestone in any project, only exceeded by the first flight. As to the oil temp reading that may be normal. I have an MGL enigma and since day one it has read 32 degrees before start and stays there until it hits 72 degrees, from that point on it will increase in normal increments. In the summer when the oil is above 75 degrees in the hanger it will read the correct temperature (as verified with a multi-meter temp probe through the dip stick port). The VDO oil pressure has never been accurate in my set up. I seems to be constantly changing in wild swings from 30 psi to above 70 psi. I added a mechanical oil pressure gauge below the panel and find it to be steady at 50 psi when flying.

Thanks everyone, for the support and encouragement!

wlarson861 wrote:The VDO oil pressure has never been accurate in my set up. I seems to be constantly changing in wild swings from 30 psi to above 70 psi. I added a mechanical oil pressure gauge below the panel and find it to be steady at 50 psi when flying.

I'm curious: The VDO folks have changed their instrument installation instructions and now recommend no Teflon paste/sealant on the threads for their pressure sensors, as it apparently screws up the grounding and thus causes problematic readings. Is it possible this is what's affecting your installation?

--Noel

It's bs. a grounding strap ground with a band clamp doesn't seem to make a difference. Put in a $20.00 mechanical gauge for peace of mind.

Congrats!

It looks like you're running pretty rich, based on the smoky exhaust?