Just watched your PM Research engine again Phillip and marvel at the quality look and workmanship. They make a good line of products for sure. Getting a dedicated, huge boiler big enough to power it might not be worth it as it would have to be large indeed. Air is not so bad and much more economical vs. a boiler.
Thanks Rog, it is a very special engine and i don't think there are many of them this side of the pond.
I have to say the raw PMR castings were superb quality, they do make very nice stuff and i'd wish they would offer some of the other steam engine kits such as the #1 mill engine as a fully machined option. This engine was machined to a very high standard and i'm confident it will run on very little pressure when properly run in, the problem is finding a suitable boiler as you point out. I don't think it would be a problem if i were to just run it without a load, however there is a lot of iron to heat up and i think it would empty a small boiler in short order ( i have tried!).
My intention is to run it on steam one day!