Dauntless coolant block drain

I am currently overhauling the V-6 in my 1967 Jeepster. The machine shop removed and subsequently lost the plug for the coolant drain plug for the block. I am having trouble trying to figure out what size it is. 1/8" pipe is too large. A 1/4" fine thread bolt will thread in though, but I'm afraid this won't seal. Any help would be greatly appreciated.

 

My 1965 buick skylark engine did not have this. I recently bought a newer jeep engine for parts and saw that on it. i though it was something added by a PO.

 

like this?

 

I purchased an 1/8" petcock to go in it which would not fit I also tried an 1/8" pipe nipple which was too big. I will try and post a picture of the location this afternoon but it is on the right side of the block by a soft plug

 

My 67 has nothing like that

 

I personally would never put that back in if i was to rebuild that. It would get a plug with permatex for sure.

 

That is on the passenger side back from the motor mount. This engine was supposed to be from a 70 or so. It would not turn so and I told the guy I wasn't going to buy a seized engine, so he got out a BF pipe wrench and got it to turn. I couldn't really care less because its just parts to me when I explode my current engine. The heads on this engine are different than the one on my 65 skylark. This one has 3/4 or so fine thread bolts sticking out of it above the plugs. Could be for air injection, but I have only seen that with manifolds on chevy garbage of 80s vintage.

anyway, I think the petcock would be hard to get to on a running engine. I can't believe its factory.

 

I've never seen one of those. It looks like there is a boss cast into the block right there, though. Maybe a square head plug was in there originally?

 

My engine has a small square head brass plug on the side of the block towards the rear - on both sides. Not sure if these are for draining coolant or what - if so, I expect I could just remove one or both and let the violent run out.

 

225's were also used as marine engines, and marine engines usually have a convenient way to drain the water out of them for winterization. Could it be from a marine engine?

 

I was thinking the same thing. It's not somethng I have ever seen on a normal engine.
My bother has a marine V6 I suppose I should check it out a bit closer.
I called him, he will see whats on it in the next few days.

 

The 225 that I have came from a 1969 CJ. Checked the numbers. here is a photo. If you look just ahead of the rear header tube, you can see a small boss with the brass plug...

 

The one on my spare engine/parts is on the other side of the block and farther forward. maybe even more annoying to get to.

I wouldn't be surprised if this engine wasn't actually from a cj, but PO said it was. who knows?

 

Here is a stock Dauntless being pulled from my Jeepster/Commando frame, look behind the oil dipstick area and you will see the brass plug. Oz












Edited to fix lost picture