Broken spark plug in Z1 head

So I picked up a Z1 900 engine for $50 and some other parts to boot. That is great because I need a head for another motor. I got the head off but one of the spark plugs broke due to being very rusty. I drilled out the center and tried using an EZ Out to remove it. No dice. I used copious amounts of penetrating oil. No dice. Anyone know another method. Thanks

Could try some heat.

Stir up some 1/2 & 1/2 acetone and ATF, aka MMF, for Magical Mystery Fluid.. Put the head somewhere that you will pass by it often. Apply MMF to both ends every time you pass by. I'd give it a couple of weeks to a month. Then heat the head to 300 - 350 F in an oven. Try the easy out then.

From Machinist' Workshop Magazine circa 2007:
"Machinist’s Workshop MagTM recently published some information on various penetrating oils that I found very interesting. Some of you might appreciate this. The magazine reports they tested penetrates for break out torque on rusted nuts.
They are below, as forwarded by an ex-student and professional machinist. They arranged a subjective test of all the popular penetrates with the control being the torque required to remove the nut from a “scientifically rusted” environment.
*Penetrating oil .......... Average load*
None ........................... 516 pounds
WD-40 ..................... ... 238 pounds
PB Blaster .................... 214 pounds
Liquid Wrench ............... 127 pounds
Kano Kroil .................... 106 pounds
ATF*-Acetone mix...............53 pounds

The ATF-Acetone mix was a “home brew” mix of 50 - 50 automatic transmission fluid and acetone. Note the “home brew” was better than any commercial product in this one particular test.
Our local machinist group mixed up a batch and we all now use it with equally good results. Note also that “Liquid Wrench” is almost as good as “Kroil” for about 20% of the price.
Steve from Godwin-Singer says that ATF-Acetone mix is the best and you can also use ATF- lacquer thinner 50 - 50 mix.
*AFT=Automatic Transmission Fluid"


Good Ridin'
slmjim & Z1BEBE

Ok, will try that. What if I mix up enough MMF to put in a bucket to soak the head? Its not going to eat the head or anything is it?

I've been using my own mix of ATF and
Acetone for over 40 years.
I even use it to clean freshly machined engine parts such as rebores, crank grinds... etc.

woodman260 wrote: Ok, will try that. What if I mix up enough MMF to put in a bucket to soak the head? Its not going to eat the head or anything is it?

Acetone is extremely volatile. That component would evaporate from the bucket in a matter of hours, leaving only the ATF. Keep the container of MMF tightly capped to prevent thr acetone from disappearing. Acetone is extremely flammable. Treat it as such.

MMF will not damage or stain aluminum.


Good Ridin'
slmjim & Z1BEBE

Jig the head up in an old Bridgeport Mill, drill the metal out of plug hole .
Buy a Ford 4.6, 5.4 Triton engine spark plug repair kit. Install the inserts.
Do all 4 while your at it. I have 3 heads on the bench waiting for me to fix one of these years! :lol: :lol:

I'll have to try the MMF soon.....

In the meanwhile.....the easy out design isn't / doesn't because of an inherent design flaw with them....in order to grip the broken piece of fastener, those tapered and pointed things like the squares, the spirals, the six point wedges, all have to put outward force on the broken screw, which expands it in the hole and just locks it even tighter against the threads you need to preserve. On something big like a spark plug, were the hole runs straight thru it, I would carefully file two notches / slots 180 deg. apart and stick a giant flat screwdriver in, one that has a square shank or a bolster that accepts a wrench near the handle, and just fits in the slots w/o having to be driven in with a hammer. Then all the force you put into twisting will go toward turning the broken piece, and not so much trying to wedge it even tighter into the outside threads....

Well thought I would get ballsy and try drilling it out and use a tap to clean out the threads and hope to save them. So I kept drilling it out bigger and bigger. I was scared I would ruin the threads. I drilled until I was a C- hair away from the threads, I then took a punch and pushed an edge of the remains of the spark plug in enough for a pair of needle nose pliers to grip. I pulled and unraveled the remains of the spark plug sleeve. It was beautiful. Threads were left if perfect condition....and I did not even need the tap! I was very happy with these results. Thanks for all the advice.

I've found that's the best way of going about it.
Steve

That is all great information. Thanks I have learned a lot. One could also heat the head and then apply dry ice to the broken part.

They use that process out in the field for removing bearings and sleeves to fix heavy equipment where mechanical presses aren't available.
Glad you got it out!
Bill

Keyboard spray is a good tool too. I gave away three cans, I shouldn't have, I could have used it on the roof of my truck where it has a big dent I can't get to. Now I'll have to buy some more.
Steve