The main problem that has to be overcome is the one of "Mindset" As we often see(?) in audio reproduction, as far as the younger generation is concerned LOUD IS GOOD.
Ian (Kiwimodller) highlighted a misnomer in that applying a higher heat source would substitute for a lack of steam volume production in a specific boiler. Heating area was the answer, not heat intensity, having said that, steam overproduction is just as big a vice. Why have a boiler producing vast volumes of steam to power an oscillator when most is escaping via the safety valve.
Many years ago, pre-motorways, I fitted an 18T engine sprocket to a motorbike that nomally had a 21T as standard everyday use. This was because I was going "Down the A1" on a long (For me) trip. Top gear on the long straight roads was great, no stress on the engine, BUT in towns, what a b***h, I was counting all four strokes of the engine in first gear and having to slip the clutch to keep moving.
How many try to employ the same parameters to toy engines?? The two "reference" books that should be in every steam addicts library are K.N.Harris's Model Stationary and Marine Steam Engines and Model Boilers and Boilermaking (Oh H**l is he wittering about those AGAIN). To find the answer, one needs to understand the problem and by looking at and applying first principles which the forementioned volumes explain fully, it becomes obvious that for a given engine size and steam requirement a suitable boiler type and size can be deduced. "But I'm not very good at Maffs" OK, DON'T meddle, if you can't work it out, leave the construction and experimentation to someone who can or play in isolation far from any you might injure if you've got it wrong. Seen so many Gung Ho threads on "Other" sites where a caveat emptor attitude is taken re safety or common sense[/b for that matter exists.
The only difference in the books mentioned is that the safety valve requirements to comply with the Blue Book would have to be changed as more recent thinking on steam escape hole sizes has been further investigated in recent years (well forty at least). I'm not trying to put the beginners off, but there are well founded reasons for not putting a Vee8 in a Mini, and the basic steam principles still apply from their original conception, thanks Messers Boyle, Stevenson, Rev. Stirling et al.