chasing spark plug threads

[Alan O'Connell]

Does anyone make an accurate tap to chase early V-8 spark plug threads?

 

[big deuce]

https://www.summitracing.com/parts/oes-25124/overview

 

[drolston]

Is it okay to use such a chaser with heads on the engine. Like, I have a plug that was loose and need to clean the carbon from the threads. But some metal could fall into the chamber. Would it just blow out the exhaust?

 

[big deuce]

Use a air chuck to blow debris out of chamber.

 

[ActionYobbo]

Put grease on the thread tap so it collects and holds the crud

 

[Mart]

Never tried it but if the exhaust valve were slightly open it might be possible to have an air line blowing into the exhaust pipe. That would tend to blow any debris out of the plug hole. You wouldn't want the exhaust valve too high though because the exhaust is beneath the plug hole and you want to be able to screw the thread restorer tap in there. As mentioned, grease on the tap will help. Mind your eyes if blowing air up the exhaust.

 

[drolston]

Good advice. I think a dab of stringy wheel bearing grease would catch most of it.

 

[tubman]

I really don't think all of this is necessary. If you are dislodging any amount of metal at all with a rethreading tool, you probably have more serious problems. Rethreaders, shouldn't be cutting new threads, just pushing the metal back where it should be. Carbona on the other hand, shouldn't cause a problem.

All this being said, nobody ever got into worse trouble being too careful.