The functions are not working:
"Maximum stack size for diesel engine (-1 to disable function)": 60, (he set 60, the player throws 60, then clicks add more and then throws up to 100 barrels (although there is a limit of 60).)
"Running time per fuel units (time in seconds)": 1.0, (I put 1 second to check, but the barrels are still digging for 2 minutes each.)