spark plug hole repair Options

[WildBill]

I was wondering if anyone has ever drilled/tapped the heads to use larger plugs. Both my 1973 2.0 heads have one bad plug hole, one was heli-coiled and the other was stripped when I bought the car. I live in the middle of nowhere and don't really want to mail the heads to a unknown machine shop unless I have to. Any ideas would be appreciated. Thanks

[HAM Inc]

Try Jim Pendergrass for Time Serts. 1800 926 1847 He will likely be cheaper. You want the 15mm length, (not the 17mm).
Time-Serts require some attention that they didn't use to. The shoulders tend to be a little larger than the counterbore that the tool cuts. I always make sure the shoulder will fit the counterbore before installing. I usually have to put them in my lathe and very lightly file the shoulder down a few thousanths.

You may have a tough time if you already have a helicoil in the head. The helicoil thread is the same as the Time-Sert threads so if the threads in the head are okay then you dodged a bullet. Otherwise you will have no choice other than to pull the head and have weld work done. As for other inserts, once the original threads have been cut away for an insert (or helicoil) you usually won't have much luck with a different insert. There usually isn't enough meat left in the boss.

If you try to jump up to the big plugs Ford used you will cut away the plug boss on the ex. side for sure and likely on the intake side too. It will be a mess.

BTW, many years ago I spent a week in Moscow, ID one weekend. Not many pretty girls and nothing to do but drink... a lot!