I have a plan Stationary Engine from the seventies, and am considering it for my first proper build. It specifies using Gunmetal for the Cylinder and steam box but I have suitable brass 'in stock' to do the job, is that OK? I will only be running it on compressed air.
It will be fine if you're running it for short periods, just bear in mind to squirt a shot or two of cylinder oil / light hydraulic oil into the inlet, it will run fine,