I may be getting in over my head here, but----
A “swept volume” calculation in it’s most simple terms, is the volume of total gases that the engine sucks in, right?
That’s volume = pi X r^2 of the cylinder X piston travel.
-Count the number of intake strokes per unit time Let’s say one minute. (example: for a 4 cycle engine, that’s half the rpms).
Multiply the volume by the number of intake strokes to get total THEORETICAL gases sucked in in one minute.
But that’s where things get hard.
-We don’t know how full the combustion chamber actually gets because of valve timing issues and gas flow restrictions in the intake system.
-If we are talking about woodgas, we don’t know the exact Fuel to Air ratio at any given moment, although we can approximate it. i have heard it’s roughly 1:1 when things are going right.
-An engine at idle has a severe restriction at the mixer, so the cylinder volume is getting a lot less combustion gas. I suppose some math guys can figure that out.
-Of course the engine at “full power” has the least intake restriction as mentiioned earlier.
Well, one thought that comes to mind:
Get a large plastic bag. Based on about half of the theoretical intake volume done earlier, the bag should be large enough to hold a few minutes of woodgas.
Measure its fully inflated volume.
Flatten it out and then completely fill it with the best woodgas you can make.
Set up a valving system so you can port the bag into the woodgas side of the mixer
Get your engine going and warmed up.
Start a timer and switch to the bag.
Run the system until the bag is empty. Stop the timer.
Calculate the number of cc’s, cubic inches or whaterver per minute and you have your answer.
Of course, you could still “split hairs” over the difference between gas from the bag and gas from the reactor.
-It was just a thought.
Anyway, I did use this 'bag" process several years ago (time to FILL the bag) to figure how much gas I could actually get out of my JXQ-10 gasifier. I wanted to see how close the mfr’s specs were to reality. And then, I wanted to see how much beyond the specs I could take it.
I didn’t invent the idea. But I can’t remember where I found it.