VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 twisted off spark plug #6 how best to fix

I put to much torque on #6 plug and it broke off leaving threads in block..how best to remove ? 1948 216 motor

Did the insulator tip pull up out the top leaving an open hole in the middle or are the "guts" still inside the threaded base?

Sorry to hear about the problem. It can sometimes be difficult to get a straight shot at #6 due to the how far towards the firewall it is located.

Did it break while you were trying to remove it or install it?

What portion of the plug is left in the head? Is it the full metal piece or just the threaded end of the metal housing?

You might be able to get it out with an extractor if as Tim notes all the "guts" are gone.

If it broke while you were trying to remove it my guess is that the metal body is stuck to the threads in the head. You might try penetrating oil and let it sit for a few days.

If there is enough of the metal body left to grab with a good spark plug socket you should try to tighten it slightly. Sometimes that will break the threads loose. Then you can work it in and out to gradually remove it.

Once you get it out I suggest that you run a spark plug thread chasing tap in each hole. Then use just a little anti-seize on the threads when you install the new plugs.

Keep us posted.

Just the plug base is in block so there is a hole for extractor

I take it this is an old plug you were trying to remove?

You want to make sure you get it out while you have lots of material to work with and not need several attempts that chew it up. If you have a MAP or Acetylene torch, you could heat the remaining portion until it turns pink and this should free it up as it expands. Give it a shot of penetrating oil as it cools a bit (it shrinks as it cools) and then use the fattest extractor you can fit it to spin it out, oiling as you go.

If you haven't got a set of extractors they are worth buying if you're working on any car, ever at all in the future, same with a hot torch. Heat is your friend.

When you put new plugs in you can prevent a repeat by putting a dab of anti-seize on the plug threads before you install.

A small square easy-out can be pounded gently into the remaining metal. Strat and run engine with THAT SPARK PLUG REMOVED SO AS TO BLOW OUT ANY JUNK THAT FELL IN ON TOP OF THE PISTON.
Putting anti-sieze on the thread is not recommended as it insulates the heat of the plug. Those little plus are torqued to only about 15 foot pounds.

I recommend Gene's advice. Most of the other advice except the gook stuff, is sound. as well.

If the extractor doesn't workl tun consider this as an opportinity to rework the head. Just slip it off and take it to a auto machine shop and have them tanked and overhaul it. (The machine shop may recommend valve seat hardeners. According to respected advice here on chatter those hardened seats are not needed. Your call.) Get a valve grind set of gaskets and put it (head) back on. Piece o' cake.

Charlie

FWIW I had a difficult plug early on when working on my '38. I started putting a dab of anti-seize on the plugs at reinstall since and have had no issues of any kind. I can see a possible problem if you really slather it on but just a dab won't hurt anything and will very possibly prevent this issue from happening again.

There are anti-seize products that have metal components. They should not interfere with grounding the spark plugs to the head.

I have used anti-seize on plugs for years, especially on aluminum heads with no issues.

Antisize will not help when you over torque it and breaks it

If the plug body broke below the gasket which is the common place the threads only may not take much effort to remove. If it broke leaving the gasket clamped it may take a lot more effort to remove and considering which 1 it may well involve removing the head for access.
Tony

Torque applies both ways, installing and removing. If it was stuck and broke while trying to remove it the anti-seize will help keep that from happening again. The OP didn't specify if it was installing or removing but the way it was worded, and the fact that torquing one that hard on install is almost unheard of to me, left me with the impression he was referring to a removal.

Also, take a shop vac and try to vacuum stuff out of the hole.

Then use tape and add a small rubber hose to then end of the hose and use that to get inside the hole once the plug is removed.

The way I read it he tightened too much on the install. That being the case often the threads will break off below the gasket that seals against the head which will often release the tension on the threads allowing them to be turned out with your finger due to no damage.
Tony

tonyw,thats what happened to strong for old geezer,I'm used to engines with a sensible spark plug,I tried an easy out but it wasn't easy,so I put some wd on it a let it set..got side tracked will try again.

WD-40 is not what you need.

I got the sob out.found the proper easy out and I did not use wd other than mosquito spray I used some camel piss and it came out A OK ,so i'm back on the road..so the bottom line of this post is do use force to tighten spark plugs in a 216,have small child tighten them for you and you won't have any problem..