I need to remind that it seems to run as well without the spacer as it does with the spacer. I can not say, for sure, that it runs better without the space. What I can say is that I thought that it seemed to be a nice run and then I noticed that there was no air space.
I put a lot of effort to reduce the restriction in this system. Even the 2" grate hole is an effort to reduce vacuum. So, what a surprise to find out that it ran just as well capped up! Possibly vacuum concentrated at the point of reaction does help or possible Eddy Ramos thought that the air becomes more preheated by clinging to the hot tank. I do not know.
Yes, it looks good ! ! !
Saturday I’ll dig up a feeler gauge. We are looking at two as pressed surfaces touching, one painted.