Originally Posted by
1967brutus
I have actually visually seen this effect when I did the first tests (a veco 19 running glow fuel and the solenoid) about 8 or 9 years ago.
Back then my at the time availlable camera did not allow me to record it on video, but what I saw:
The perry carb, as most of us know, does not really have a spraybar across the venturi, but rather a tiny nozzle that only protrudes something like 0,02~0,03" into the intake.
Looking straight into the intake of the Perry carb, running on the needle there was a jet of fuel visible that frayed a bit at the edges, but reached all the way to the other side of the intake bore where liquid fuel would splash against the wall.
When running on the solenoid, there was no jet of fuel visible, but a "misty area" in the vincinity of the fuel nozzle, and reached only roughly about halfway of the intake. In other words, a finer mist and a better mixing with the air inflow.
Chris, if you would want to know more about this,, I'd say, try and look straight into the intake of one of your home-made carbs, and observe, if possible, the fuel outflow of that 3D printer nozzle.
Then de-energize the solenoid and temporary install a remote NVA in the fuel line, start it and adjust it to run "as lean as possible" on the NVA, and look again.
There should be a distinct visual difference in how the fuel leaves the nozzle. That will help you understand how this effect works.
I am pretty sure you will also, given a bit of time, notice your exhaust residue turn black and cruddy.
And if you have the equipment to catch it on video or photo, that would be a great learning tool for us all.