adding steam and locomotive sound to a vehicle

[Mazerate]

I am building a one man steam vehicle (off track train). IT will tow 4 trailers (train cars). This vehicle is driven by 4 car batteries, and an electric motor. The after look, is a large boiler on the top, with driver, and piston pushers on the lower sides. We have a ton  of work to do, but I am having trouble planning the steam/smoke, and sound. I have never been on a steamer, and want to mimic the sounds and steam release as close as possible. Because this vehicle is electric, I can also drive at indoor venues, and need the smoke/ steam to work off of D/C (car batteries), be indoor safe, and supply a decent amount of steam/smoke. The sound I figure will be 2 or 3 parts....boiler sounds, steam/ pressure sounds, and others (that I am not aware of). I am planning to put speakers in the appropriate places internally.

My background - we create movie props. I am a gun wrangler. I have a good shop (drill press, grinder, cross cut saw, table saw, dremel and other hand tools). I don't work with electric a lot, but am not intimidated.  My father had a HO gauge train table and insisted on all locomotives. I am new to joining the steam punk era, but have been fascinated. I am looking for a creative hobby to have a ton of fun with.

LOL any links, or suggestions would be appreciated.

[James Harrison]

If you want to make it as realistic/ convincing as possible, it would be worth bearing in mind that the chuff-chuff-chuff is synchronised with the wheels and valvegear. 

The cylinders are generally somewhere between 90 and 120 degrees out of sync with each other; as steam pushes the one piston out and then turns the wheels, the rotation action of the wheel pushes the piston on the other side back in.  As that piston is going back in a valve opens to let the exhaust steam out into the smokebox, where it immediately vents to atmosphere via the smokestack.  This creates not only the characteristic chuff-chuff but also draws air over the fire and then through the boiler tubes and creates a draught, which clears the ash out of the boiler, generally taking it out the smokestack in synchronised puffs. 

Not sure how you might go about recreating this but some sort of mechanical linkage might be useful.