The VeeCU

[WesRagle]

Hi Guys,

The measured voltage is low, so some care with the oscilloscope's bandwidth settings are helpful to get good measurement SNR.

Ain't that the truth. I bought one of the cheap shunts from Amazon. Here are the best pics I could get with all the arcs and sparks flying around. I couldn't use my high amperage power supply, It's a switcher and generated too much noise. So, I used my old bench supply, which is light for the load, but I turned it down to 5 volts and it was was good with that. Anyway, at 8 mSec dwell I'm about 75 % of the way up the RL charging curve. Hopefully I'll be able to perform a "live" test of spark duration soon. As long as the duration is between 1 and 2 mSec over a reasonable operating voltage range 8 mSec should be fine. There really isn't much to be gained by going shorter.

Pic with a long dwell to show 100% current.


Pic with 8 mSec Dwell shows about 75% charge.


Wes

[Skippydiesel]

Fantastic opening statemnt - I think you know me!

In Australia we call "Suits" "Bean Counters" - uttered with considerable contempt.

As you articulate so well - they control the $$ and therefore your professional future in that organisation.

I only wish I had read your opening statement, about fifty years ago (unfortunately, knowing all there was to know, I probably would have ignored your advice).

My ongoing war with the Bean Counters, eventually resulted in an early retirement, known as a Voluntary(????) Redundancy. Turned out rather well - got to referbish my aircraft and take up competitive endurance horse riding.

[WesRagle]

Hey Guys,

Some progress.

Frankenpanel 2.0 is complete and wired. The analog output of the Innovate AFR gauge is wired to a spare analog input of the VeeCU. All sensor inputs, accept the alternator, check normal. Central Command is ready for action. Now I have to clean shop so I can run the engine at a decent power level :-)



VeeCU Prototype #2 is velcroed to the bench.




The secondary ignition plugs are wired outside the engine for testing of ignition timing.



That brings me to a problem I am having. The timing light I bought was selected based on ease of mounting. It was also cheap, so that was a bonus. However, I only get intermittent trigger on either primary or secondary ignition plugs.




Question: Can someone direct me to a timing light that they have used (and are happy with) on a VW powered aircraft with a magneto and electronic secondary ignition?

Thanks for Your Time,

Wes

[Bryan Cotton]

Hey Guys,

Question: Can someone direct me to a timing light that they have used (and are happy with) on a VW powered aircraft with a magneto and electronic secondary ignition?

Thanks for Your Time,

Wes

https://www.harborfreight.com/timing-li ... 40963.html

Just tape the stupid advance dial on the back to zero.

[WesRagle]

Thanks Bryan,

That one works!



Wes

[WesRagle]

Hi Guys,

Finally ..., I turned on the fuel injectors.

Here are some pics from the first FI run.

This shows that the calculated FF matches closely with the measured FF. Top row far right on the EIS.



This shows the EGT spread with no injector trim. The injections are timed to *NOT* inject directly into an open valve. I was surprised they weren't closer. Cylinders numbered #1 Right Front, #2 Right Rear, #3 Left Front, #4 Left Rear.



This shows the power draw of all instruments, injectors, secondary ignition, and fuel pump at approximately 2000 RPM.



I need to slow down some now and put the test bed charging system back together. I was unable to start the engine on fuel injection because the power supply I'm using tripped off line due to the high ignition current required during start. Lots of experimenting to come.

A Good Day,

Wes

[Dave Wolfe]

Congrats!

[WesRagle]

Congrats!

Thanks Dave.

I was surprised it worked right off the bat. I decided to keep the tune and VE tables separate. I just tossed in a guess of 0.75 VE over the entire RPM range and set the tune to just echo the mixture pot for a target mixture.

BTW, I pulled my head out and realized I could start on the mag without secondary ignition and so can start on FI with the bench supply. It worked great. It will be nice not worrying about whether I will get a start or not during the rest of the testing. I also won't have to put up with that puddle of gas under the Revflow after every engine run.

Life just keeps getting better :-)

Wes

[WesRagle]

Hi Guys,

I was running the test engine yesterday evening, testing injector trimming, when all of the sudden the engine started running erratically. I quickly pulled the throttle to idle and the engine surged and died.

Oh well. Ref.: https://www.youtube.com/watch?v=AynXoLjYrKc

Probably best. I need to solve some issues with the test engine before I go further.

Since day one the oil pressure on the test engine has been off, not right. Oil pressure 70 to 80 at start. That OK. By the time the oil temp (measured at the sump) reaches 130 the oil pressure is down to 25 or so (tested with two different senders). The oil temperature never gets above about 135 at which point the oil pressure is down to about 20 at 2500 RPM. I don't know a lot about the oil system, but I'm hoping I can just fiddle with the springs some, and maybe block off some of the cooling air, and get things in line. Here are some random pics of the oil system that might (or might not) shed some light on the situation.








Suggestions appreciated.

Thanks for Your Time,

Wes