Old gas-mixture / carburators

I did collect these pictures from the internet.
Nice for learning.
What intrigues me is the fact that most of these devices adjust their air to gas mixture the same time as they use the throttle.
Most of these pictures come from Francois his website.

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Good stuff KoenVL
Some of these show integral gasoline/petrol circuts. Sometimes obviously for starting up on. Sometimes not-so-obvious for power boosting. One shows a whole bolt-on sub-gasoline/petrol carburetor.
Most all show the proportional downsizing of the air butterfly (papillon) valve versus the gas supply butterfly valve.
Comfusing that at first given the known ~1 to 1 ratios needed when a fellow is starting out with wood/charcoal fuels.
Tricks of understanding comes once you have bent nose come to realize in a Suction driven gasifer system that the fuel gases ARE NOT SUPPPLIED AT ALL - but dragged in by engine brute negative pressure force. Takes engine produced power to do this. ONE of the reasons for less available engine shaft out power. Engine power got used up sucking hard the whole gasifer train.
The atmospheric air in comparison mostly just falls/jumps in.
So two primary factors there to get your 1 to1 balance. Butterfly valves flow rates change dramatically with the angle of plate opening. Your best contol is at 10 to 30 degrees of butterfly plate opening. And since you cannot push the fuel gas flow in without pressure boosting the actual gasifer system then you must match the actual “easy jumping-in” air stream flow rate to the actual “hard pulled in” fuel gas stream flow rate. Bluntly you have to choke the air DOWN to match the gas stream dragged kicking and screaming into the engine. Or run too air rich and misfire. Undersizing the air butterfly gives you this matching restiction at enough valve plate opening to have good control. A big butterfly valve just off of fully closed has a wicked quick on-off effect.

Air and fuel starved is the primary reasons that IC piston engines have less power on wood and charcoal gas versus when on gasoline and propane. Ain’t about the BTU’s/Calories/Joules of the actual fuels but getting then enough of now both air/oxegen; and fuels H’s and C’s; into the engine cylinder to produce the heat and pressure pushing down on the movable piston top.

Interesting differences on these different mixers at the actual fuel gases and air blending interfaces strategies.
Some intentionally turbulant.
Some Intentionally smoother laminar flows.
These cannot work equally as well.

Thanks for this
Steve Unruh

Steve , another excellent post sir !

You explain it so well.

As they say in Parliament “Heah, heah!”

I’m adding this to my ongoing encyclopedia called “Steve’s Book of Wisdom”