First of all, I agree about the hula-balu. It was nice meeting everyone but even nicer when they left. Also it’s a real strain running around dressed in clothes you have to watch out not to dirty.
Now to the questionnaire.
1 Reduction insulation. You’re right, I use about the same way holding ash around the Rabbit reduction, only it’s a straight tube.
2 The 4" restriction. That’s 100mm.
In the little Rabbit gasifier I use a 90mm restriction, still with good idle capabilities. This larger restriction has a +25% csa, while the Mazda engine has a +40% cylinder volume. I see no reason to go with a smaller restriction.
Before I let the videos explain the rest I’ll just comment on your final question about nozzle dimentions. I belive those certain Imbert dimensions are important to get the proper air velocities and pentration at idle and very low demand. However I don’t think it matters much at full power. As I mentioned my upper nozzles will be turned on only at open road speeds to try make the gasifier bigger. Of course I would have liked to be able to increase the restriction opening too, but you can’t have it all.
Remember, all of this is very experimental. I’m one of those who always try to reinvent the wheel.
Oh, the cut in half rubber hose keeping water from getting to close to the heat on the hopper bottom, is held down with a ss ring cut out from a washing mashine drum. The ring is tightened down with bolts, and yes I can reach them from the filler lid.
I hope your new pajamas suits you. A photo would give us the oppertunity to judge for ourselves