[olddog]

The edelbrock heads have helicoil in the threaded holes that the intake bots go into. The second bolt in from the ends are the ones that are in the milled out spot between the intake ports. All four of these spots a bolt would only turn in 3 threads by finger. I can only get about a half turn more with a nut driver. You can twist the bolt in with a rachet.

So I tried running a tap down them. It felt like the tap was hitting the bottom, but I only gain a turn at best on a couple holes. So I tried a bottom tap. It felt like the tap was getting tight. I kept going back and forth, but it would not free any at all. I tried to go down a little further and it just stopped. Then when I backed up the helicoil backed out a couple thread. If I run the tap back in I can turn the helicoil back in, but then it backs out again. I cannot get it in nor take it out.

I tried tapping a second hole very easy, again the tap does not help to free up the threads. It acts to me like the tap cannot cut the helicoil. I suspect the hole the helicoils screw into are not tapped correctly causing a tight fit, who knows.

So what is the best method to remove the helicoils? I want to re-tap the holes and put new helicoils in.