Welcome Eugene & Stephane.
Stephane, from what you have shown us (especially the V8!) I think you are a class or 3 ahead of me!
Eugene, Let's talk boilers. I found a couple of years ago that I didn't know enough, so have (with advice from others) taught myself a lot of the complexities of boiler design. And now have a better appreciation of what is SAFE and what is just not quite safe enough. A few have used my advice (and not complained), so I am comfortable to take your designs/needs and recommend any tweaks I think can improve them - if necessary. As an Engineer for 50 years at work I have a bit of background in Design and Manufacture, Quality Assurance and also as a Safety Officer, etc....
As Boilers are potential "bombs" (devices full of stored energy that can be released very rapidly during a failure), there are Regulations for any public display, or even home insurance. Without a certified test, things may not be "as planned" in the event of any mishap.
Therefore, if you wish, please send me some details of your boiler "needs" and thoughts of what you think you want to do. Either directly or through a thread.
Hope I can help?
K2