Heli-coil in aluminum head

HeliCoil is the name of a company that was the originator of the "wound-wire" type of thread repair insert, but wound-wire inserts aren't the only type of thread repair insert that the HeliCoil company makes.

Wound-wire inserts -- what most people mean when they use the HeliCoil brand name as a generic descriptor -- ARE used to repair spark plug threads, but they make a third-rate repair. Solid inserts are much better suited to this particular job.

The queen of the solid insert is the Time-Sert, but the installation tooling is expensive enough to make the Time-Sert a take-it-to-the-machine-shop proposition for most of us.

Next step down are a couple of inserts that are essentially glued in place. My personal favorite is the EZ-Lok insert (check their website at www.ezlok.com ), but the HeliCoil company's brand of solid insert, which they call Sav-A-Thread, is probably as good.

John

For a simple Wisconsin head, there's nothing wrong with a simple Heli-Coil.

I certainly would not call it a third-rate repair.

If they were THAT bad, there would be a lot of spark plugs popping out of cylinder heads!

I certainly do not disagree with you on the other options, I'm just making the point a simple Heli-Coil will do the job!