Tuesday, August 31, 2021

First engine test

I'll edit this post as more data is gathered and issues are resolved.

The tires were aired up to help make it easier to roll the plane.

I put a gallon of fuel in each tank and checked for leaks.  The sump drain plug needed tightened on the copilot side.  I got disrupted before finding the leak and have a nice blue stain already.    A plug in the fuel pump assembly needed sealant and tightened.

8 quarts of mineral oil were added.   Spark plugs removed.  Fogging spray (lubricant) was shot into the cylinders.   The engine was easily spun by hand initially.    Then the starter was used to bring the oil pressure up and it peaked at 50 psi.   No leaks were detected.

The EI/EFI system was turned on/off several times to cycle the injectors while the fuel system was pressurized in hopes of purging any air out of the lines.   The injector line was temporarily removed from #1 with a quick cycle on/off of the fuel pumps and a shot of fuel came out of the line.  Additional fuel was added, to the left tank for a total of about 5 gallons in the left and only one in the right.

Several neighbors and friends assisted and observed, although I probably would have wanted to do this alone, some friends and neighbors wanted to be on site for the event. Some of the folks were really helpful with observation and analysis and for that I'm very grateful.

Wheel chocks and traffic cones were put in place when the plane was pushed out on 08/30/2021 6:15 PM.

Several people looked things over, loose items were moved to avoid anything going through the prop.  Some were wearing ear protection (this thing is loud).

Both master/buss relays were energized along with the A fuel pump, A & B ECU's and coils.   The throttle was set to idle, mixture centered.  Prop was clear, starter engaged.  Several combustion cycles occurred but the engine died.   A quick inspection revealed fuel was leaking at the connection to the fuel pressure sensor and the connection was tightened.  Some of the spark plug wires didn't seem fully engaged so were all rechecked with a few of them going on a bit further.

Another attempt to start was made resulting in a rather rough running engine.   The #3 cylinder appeared not to be getting fuel or spark.   We couldn't hear the #3 injector clicking when cycling the ECU off/on so I disconnected the injectors electrical plug and hit it a few times with 12 vdc.  The first time, it didn't click but each consecutive time it did.   We also noticed the #4 CHT probe was giving anomalous readings (rather cold) despite the head was hot to the touch.  The spade connections appeared good to the probe.

The engine was restarted with the throttle opened slightly.  Adjusting the mixture control didn't seem to have much effect.  The Dynon panel was showing 2x the RPM that the SDS programmer was showing and the MAP pressure on Skyview and SDS was suspiciously high (20 inches) with RPM now at about 1200.

A small amount of oil had begun to drip from the back of the motor and was determined to be at one of the AN-8 hose connections.  It was tightened.

We discussed the probable cause of the erroneous MAP pressure and suspect the port being used at the butterfly was to close to ambient pressure.  Two of the more mechanically experienced helpers advised that the port should be closer to a cylinder intake port, although they're unfamiliar with the SDS system, so I committed to researching this further and will test for leaks.

Update:  The Borla fuel pressure regulator itself was leaking vacuum.  I used some Loctite 680 on the nut/nipple/screw threads.  Tightened the oil hose near the oil filter.  Swapped 2 & 4 CHT connections, found another leaking plug in the fuel pump assembly.  Set the Dynon RPM tach settings to 2 pulses per revolution.    Ran the engine a second time, started up and idled decently at 800 rpm.   The Dynon tach more closely matches the SDS programmer but isn't exact.  The pad alternator doesn't seem to be charging.  Switching coils off/on, found Coil A (top plugs) didn't seem to be working.  Found it had been switched off in the VPX.  It normally is activated when VPX switch #1 is on and a panel switch is on. The CHT's seemed to be operating properly now so swapped probes back.

Next update:  Found a problem where the #1 coil was not firing.   Traced the issue to transposed white/white blue wires between the firewall and DB25 on the primary ECI to pins 9 and 11.  

Update 9/11/21:  Per instructions from Ross, updated the magnet positions, increased static fuel pressure to 45 psi.  Set the lower RPM advance to 20 degrees.  Tested redundancy by only turning coils on/off and switching the injectors.  Adjusted the mixture knob to -24% for a smooth idle at 700 RPM.  Main alternator is putting out but the pad alternator didn't appear to be putting out at idle.  Increased RPM to 1500 and it started charging.






Sunday, August 22, 2021

2021 08-22 update

Despite not posting updates, I've been making progress.  Some of it is three steps forward and two back...

We recently enjoyed a trip to OSH, then Florida and a stop in Huntsville AL to see Russ and N67TM.  He did a nice job of following the plans and keeping things simple.

The only flying I've done much of lately is as safety pilot for my friend that's working on his IFR.
It sounds like there's a Velocity CFI in Dallas I might be able to get more transition training from.

I chatted with Scott Fish about a few things and he commented that he'd also had a list that had would shrink and grow as he was finishing.   Items that are cosmetic should go to the bottom of the list and items that are necessary for the DAR inspection should go to the top.  
Item's almost complete (maybe I'll post photos and move to a real web site on some cold wintery days):
Vortilons made (prepping for paint)
Trailing edge fences (prepping for paint)
Front console/armrest (prepping for paint)

ADAHRS module mounted.
Pitot/Static tubes connected.

Rudder cables connected to the pedals. 
Ailerons connected. 
Brakes bled after replacing the seals and O-rings.

Exhaust nuts tightened.
Crankcase breather tube installed.

Wing root heat shield (Thermotec) installed.

Pitch trim actuator mounted/tweaked...
Dynon software updated.

N-numbers ordered.
Wheel pants ordered from Aerocomposites.

I still have a few avionics parts to mount such as the ADS-B receiver, GPS2020 antenna and the back up battery.   Some wiring work left, mostly audio connections and tidying up behind the IP.