Hi Gary,
for the debate; i use the value of comparing the different gas contents with a 100% stoichiometric corect adjustment = lambda 1
If you look into the spreadsheet eariar, and play with the value’s, then you’ll notice that: if you increase the amount of Co, you also need to increase the amount of air in your combustion mixture.
The amount of Co2 going to the engine is replacing the nitrogen if all the other values stay the same.
adding power into the gas by increasing a combustible in a percentage, also means that you have to ad oxygen into your mixture towards the engine thus also increasing the amount of nitrogen.
This basic theoretical numbers do indicate dough the baselines from the happenings.
In the real world the fluctuations always will be there, therefore i put the sentence "automatic mixture control a must " ? with a question mark.
Since most gasifiers are running in a “batch mode” there will be difference between startup - middle and end of cycle quality in the gas.
I did put al my observations in a single perspective and formed my conclusions based on my perspective only…
Sure future will learn me more 
The governor , as you mentioned, is doing a great job in compensating, but what is invissible for you is if the governor reacts the same as in the beginning or different during the whole batch run ?
Adding Co2 to cool down the temperature is an old technique which i re-discovered thanks to your simple fire systems.
The reading hints from Steve U and the comments of every builder on DOW made me study further.
EGR is a starter, but if you look deep into it you’ll probably find following as a solid statement;
Adding exhaust gas into the air intake of the gasifier dilutes the amount of oxygen in the air, oxygen needed to generate heat for combustion of charcoal and reduction in the following zone.
Since all the conversions to be done in the gasifiers are , bottom line, consuming charcoal burned by oxygen, is it important to have just the proper amount of oxygen added as required to do the job.
Since air consist of largely 79% of inert and 21% of oxygen, it is better for the gasifier to give it only oxygen with the least dilution possible.
Since the known process from converting Co2 into Co takes away heat from the process and gives back a richer gas content without diluting the mixture with inert gasses…
Putting al these values into the perspective and in the spreadsheet makes one important statement visible: Any gasifier with a constant quality of gas will run a IC engine
Once adjusted and no parameters changing, the engine will run and produce power.
Old knowledge and examples from ww2 are showing they did exactly what i am describing, adjusting throttle and mixing valve simultaneously. even did find earlier testing and using adjustable nozzles, automatic, depending the vacuum of the engine.
But the experiments are there to learn. a smaller gasifier with the correct tweaking can produce same energy but more efficient.
With the knowledge available we can reduce the erors we would make if we only do trials
Back to the temperatures:
Charcoal can get really hot :-), it does reach temperatures where the ashes melt, depending on the feedstock of course.
The great thing about your GGG is the temperature retaining capability, where most other gasifiers having a great heat loss by venting the hot gas, here the hot gas gets cooled down with the feedstock in direct contact…
I want to continue on that base and the future is looking great whit that basic setup.
For political reasons and because its true, i will proclaim further , in simple words, that using a gasifier = consuming Co2 ( reducing it into Co)
Gary , i enjoyed reading your reply and i sure will enjoy reading more of those.
