360 degrees?

We must be talking about 2 different dimensions. With my many pictures and the info I provided I am not sure what you are not seeing.

3/4" and 2" respectively. (The 2" was measured weeks ago in this conversation. The 3/4" is the thickness of the head where the GP would thread into.)

I think the many pics clearly show there is 360 degrees before. But nothing after. Bottom line is, I can run a tap where GP originally threaded in to. Can not in the gaping hole.

So the 1/2" hole, from 3/4" depth to 2" depth (for 1.25") there is no aluminum 360 degree of the circumference? And that 360 degree circumference breach is all into the intake?

Do I have a clear picture in my mind now?

Yes. Exactly.

That gaping hole is a lot bigger than I could make out from the photos. I'll draw up a diagram later.

Did you remove the injector and cranked the engine? If you haven't cranked it yet. Put a towel over the head so you can see which holes had water coming out.

For such a large gaping hole that is 1.25" deep all around in the intake, epoxy putty is not going to work. Below is what I'd propose. The 14-1.5 mm machined bolt's purpose is to apply pressure on the lead plug which pushes on the remnant of the glow plug, trying to do the same thing as when you tighten the glow plug. Whether this will work or not to keep combustion gas from escaping depends on whether the glow plug seat is intact and if sufficient, even pressure can be transferred to the glow plug seat.

The 1/4-20 N.C. set screw pushes on a rubber plug which seals the coolant breach. Coolant pressure is determined by your expansion tank cap, which should be around 17 psi max.

http://i31.photobucket.com/albums/c3...502_190025.jpg

funola - this is great stuff. Let me really soak this in. I put a long day in at work today. But wanted to respond and say thank you. I like what you are proposing. and very doable I believe.

Any questions? The 1/4-20 and 14-1.5 mm taps will fit the existing holes. Be careful when tapping the 13/64" hole that you don't break the tap. Do it by hand, no power drill, use grease on the tap to pick up the shavings. Do a little at a time and wipe it off, apply more grease, till you reach the depth needed.

Is there a danger of the lead plug falling into the intake during install? You need to figure a way to prevent that. If so, can it be retrieved via the intake ports? Can the lead plug fall through an open intake valve into the cylinder? I was thinking of epoxying the lead plug to the bolt and just tighten it.

Did you vacuum out the shavings from previous drilling? You can use small diameter vinyl tubing and duct tape it to your vacuum cleaner hose for the task.

Are you sure putting a rubber plug that close to the combustion chamber is a good idea? I think it might not be.

If you look at photos Mike posted, the tip of the rubber plug breaches a small hole (approx. 1/16" ? diameter) into a coolant jacket, it sees coolant temps, not combustion temps.

So what was the outcome of this fiasco?

I sent Mike a link to a fellow who had a replacement head for sale, that was a few days ago. Haven't heard anything yet.

Glad to hear he's not futzing around trying to jury-rig the problem.

Unfortunately I do believe this is his e300. Same story, town and Mike.

https://cnj.craigslist.org/cto/5533562083.html