If it creates and implosion when at BDC, the most I think it can create is absolute vacuum of 0 psi, atmosphereric pressure will push on the bottom of the piston with a pressure of 14 psi to push the piston back up(down in the Newcomen engine). Not much pressure differential to do much work.
Newcomen steam engine - Wikipedia, the free encyclopedia
But I know nothing about brown gases or most everything else your talking about.