broken spark plug

[Troyport]

Hello, changing plugs in my 1987 V20, and 2 of them broke off with little effort. Metal was quite rusty. One came out very easily with an easy-out, so no concerns there. The second one, the porcelain broke, and now the remaining part of the plug is giving me trouble getting it out. The easy-out has slipped a few times (didn't grab enough) so I am sure there will be metal shavings in the cylinder if I am successful in removing the rest of the plug. I fear I may have to drill it to .375" to get the #5 easy out to fit better, all for sure will put more shavings in the cylinder. It looks like I can remove the inner wheel well to gain straight-on access. (It's the #8 hole) Is there any hope in vacuuming out the cylinder when (if) I get the rest of the plug out? Or at this point should I just bite the bullet and pull the head. I have to imagine that repair shops break plugs all the time, and I have never heard of a tune up turning into a head job, so maybe I am over-thinking it? I have no interest in modifying this engine, so if I removed the head I wouldn't want to do any additional work, and probably would not pull the other head. Any advice would be great, thanks.

 

[Turbo4whl]

The metal shavings from drilling will not be an issue. Use the Ridgid style screw extractors.

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Drill the correct size hole. Heat the plug, then hammer in the extractor.

 

[Ricko1966]

Crank the engine with no plug in it to help blow out shavings,grease your drill bit to catch shavings. I've drilled and tapped oil passages on assembled engines,grease the bit and tap the shavings stick to the grease

 

[Troyport]

Thanks for the advice. I made an extractor by grinding a bolt into a square, got the first one no issue. It slipped with the second one. Obviously not a great easy-out. Yesterday I purchased a set of easy-outs for hollow / soft metals, to minimize expansion of the plug. I cut apart a plug that came out intact, and measured the ID of the threaded part, it is .338" with a dial caliper. Is drilling to 3/8" (.375") needed? If yes, I have to remove the inner fender. otherwise, how much heat do I apply? Quick and hot from my oxy-acetylene? Or more gentle from a plumber's torch. I'm 60 years old, worked on cars forever, never broke a plug in my life until now. Thanks again. BTW, here's the truck. Total babe.

 

[Turbo4whl]

First, don't heat with the extractor already in. Extractors are hardened and melt at a lower temperature. Since you have the oxy-acetylene, use that. Bring some color up in the spark plug stump. Hammer in the extractor.

 

[Edelbrock]

Doesn't sound too serious. Should be able to get it out with the extractor. I recommend watching some YouTube videos on how to use them. They are fairly simple to use, but like any tool it needs to be used properly or you could make the problem worse.

As for metal shavings - like others have said - grease the bit. using compresses air works too. You put a small hose on the end of the air chuck and insert the hose deep into the cylinder. Blast air into the cylinder whole moving the hose around a bunch. The metal shaving will get blown out the spark plug hole (and right into your eyes).

Keep in mind that there are various different kinds of extractors.

 

[Bennyt]

Whenever I do this, I put affected cylinder at TDC, compressed air in exhaust pipe and shavings, hopefully, blow out as drilling.

Additionally, I WD40 or PB for a day or so.

And, white grease on bits/ extractors to catch shavings

 

[Memaloose]

You can also use a magnet to collect the metal.

 

[Grit dog]

First, don't heat with the extractor already in. Extractors are hardened and melt at a lower temperature. Since you have the oxy-acetylene, use that. Bring some color up in the spark plug stump. Hammer in the extractor.

You want to heat the head, not the spark plug. Always heat the “nut” not the bolt.

 

[Troyport]

Right, always heat the "nut".. but the nut is huge in this case, so I am thinking the theory is heating what's left of the plug will loosen the bond it has with the head, especially because it will cool off significantly by the time I get the torch off and down, extractor in and whacked, wrench on the extractor and turn... At least that's what I think...

 

[Turbo4whl]

You want to heat the head, not the spark plug. Always heat the “nut” not the bolt.

In this case, you are not heating a nut, you are heating a cast iron head. It can and will expand. The only way it can move is closer to the plug. Heating the plug it expands pushing on the cast, and closing the hole drilled in the middle. While you hammer in the extractor it cools. The push against the threads has upset the rust bond.

May have to repeat 2 times. Pull out the extractor between heat cycles. PB blaster between cycles too.

 

[Turbo4whl]

Right, always heat the "nut".. but the nut is huge in this case, so I am thinking the theory is heating what's left of the plug will loosen the bond it has with the head, especially because it will cool off significantly by the time I get the torch off and down, extractor in and whacked, wrench on the extractor and turn... At least that's what I think...

This is correct.^^^ Heating a small section of cast to color, could have ill effects on the head.

 

[Grit dog]

This is correct.^^^ Heating a small section of cast to color, could have ill effects on the head.

Agreed, on that. I wouldn’t heat the head cherry red. I still think heating the head is the right move. But to be fair I hope to never have to find out. Lol.
Been quite a few years since I’ve dealt with rusty cars. Although the rear differential drain plug on my kids clean 2017 Ram took some extra-terrestrial effort to remove.
I only had a map gas torch. But it wasn’t budging with an impact and a fabricated big ass Allen bit (welded a couple nuts onto a grade 8 bolt to make a 9/16 Allen bit). Heated the cast iron housing as hot as that little plumbing torch would get it and the steel drain plug finally came loose.

 

[Troyport]

Tried just the correct easy-out last night, thought I could get lucky, wouldn't budge. Going with the heat method in the next few days, I will post back with my results. I want to remove the inner fender to do this, it is difficult to do it from the top, can't see too well, hard to lay across the radiator especially with a lit torch in my hand. Sounds like a good way to have a really bad evening.

 

[Ricko1966]

Try driving the truck,get it hot, and removing the plug hot. Cardboard in front of the radiator if you have to. Ground the loose plug wire so it can't spark.