tin boats

[tintailoruk]

Any one with any suggestions? I am reliving my childhood, at the moment I am building a sheet metal 24gg boat length 18 inches long with a 9 inch beam, I want to place the old "phut phut" propellant system, the idea being that a small copper/brass water tank having a resonating top will suck in water from one tube and force the heated water (steam) out to another tube to propel the magnificent(LOL)craft through the water. My question is as to any recommended sizes of the "phut phut" motor.I have GOOGLED but as to sizes of this contraption I have no idea. Any HELPFUL suggestions will be appreciated, other replies with humour too will be appreciated.