'Cleaning' threads

kikboxr1

Founding Member
Jun 23, 2000
289
0
16
Atlanta, GA
I'm going to change my spark plugs this weekend, and I'd like to do something I haven't done before - clean up the threads in my GT40 aluminum heads. I haven't used a tap before so I thought I'd ask first to make sure I'm not going to mess anything up. After using a cloth and a wire brush to clean off the old anti-seize, is it safe to use a tap to kind of straighten out the threads?
 
  • Sponsors (?)


Never use a tap to clean threads, especially on an aluminum head. There is too great a chance you will start the tap off center and cut new threads. It is very easy to cut new threads in the soft aluminum.

A spark plug thread chaser is what you need. Most good auto parts stores will have them. The thread chaser will clean threads but will not cut new ones.

If you have a Dremel or die grinder, use a small cut off wheel to cut 3 or 4 slots or grooves in an old spark plug along the length of the threads. done properly, it makes an excellent thread chaser.

Keep in mind that you need to use grease or similar material in the slots of the thread chaser to capture the trash the thread chaser cleans out of the threads.
 
Hiya Michael!
The reason I wanted to 'clean' my threads was because last time I changed plugs I remember them feeling a bit odd coming out and going in. It felt like they were slightly cross threaded or something.