Makers of steam powered engines that range from small model ‘parlour engines’ to full size engines capable of powering a large boat or generator.. Free steam engine and boiler plans. drat… they’ve been moved! having updated the available options covering steam, hit and miss engines, a whole variety of things. Steam engine plans page 2 . page 2 of the popular steam engine plans free downloads – please click on the links to download the relevant files . please contact me if.