If you are "tapping" a new thread, you insert the tap as vertically into the hole as possible. You start the thread with a turn or 2, then back out 1/2 a turn, then screw it in another turn, then back out 1/2 a turn and continue this till the hole is fully threaded. Don't run the tap all the way as far as it will go (it's tapered). Go until the end of the tap has just emerged on the inside about a turn after it's reached level with the inside surface. Making a new thread is a process of going in and backing out repeatedly till the whole thread is completed.
Put some heavy grease on the tap so that it collects much of the shavings.

 

Not to tread jack but I wanted to change the drain plug return on the Comptech unit to a tapped return like the Vortech's. Has anyone done this?

 

Don't know if it has been done, but I see no reason why it would be an issue. Just order up the parts to install it in the oilpan. It's odd that you want to go that route. Many owners will turn down a Vortech because they DON'T want to tap the oilpan.

 

I took mine to a local machine shop and had him weld in the area and tap it for me. Much stronger with plenty of threads.

 

Thanks every1, and xvpr for explaining it, I've always heard of that term but never really knew how it worked..lol Guess i'll be trying this tomorrow... *crosses fingers..