I have made an all corn whiskey a couple different ways. One I boiled (cooked) the corn, which was cracked (crushed) a bit, for 60 to 90 minutes. You basically end up with a porridge. But the process is to help breakdown the starches prior to adding the enzymes to convert them to sugars.
The second way I used corn meal, and I purchased high temp alpha amylase enzyme, as well as the beta amylase. the high temp works up to 170, and the beta is like adding in your malted barley for its enzymes, which is in the 140's.
I measured out the amount of cornmeal and calculated the amount of water, which I brought to a boil, to get a good "cook" on the corn meal. I mixed this with an electric drill with a 5 gallon paint stirrer. This allowed the temp to drop enough so when I added the high temp enzymes, it went from a thick porridge to a very thin mixture within seconds. I alternated the corn meal, boiling water and enzymes until I had all the corn meal in my 55 gallon fermenter.
I left it sit and cool for about 24 hours before it was actually low enough to add the beta amylase.
I then let it cool for another 24 hours or so before pitching the Redstar bread yeast.
It turned out very good. I need to get another batch going. I have been out of commission due to rotator cuff surgery.
Good luck