Fully Self-sufficient LVL 9 Steam Engine and only 5x5x6
To turn it on, just:
1. Put at least two buckets on the conveyor belt
2. Pour some lava into the tank (the more the better)
3*. Destroy and place again a lava tank if it doesn't work.
*Be careful of pouring lava when copying on creative
4. Put one water bucket to main tank. (This should start the machine and if everything is done correctly it should work non stop)