What the heck goes here?

[mylillooker]

I’ve got a 79 Midget (1500 engine). It’s got the Weber carb on it. It had been running fine but apparently has lost a plug that was in a hole in the exhaust manifold. Most likely part of the emissions equipment that's no longer there.

The hole is about 3/8 in round and the 3/8 NPT plug doesn’t fit. The threading in the hole seems to be thinner than the 3/8 NPT plug from the hardware store. It’s in an awkward place, which has made it more difficult because if I drive somewhere to have someone take a look at it it’s too hot to even see, much less touch.

I’m hoping that someone can tell me what was in it so I could have a reference point in my search to plug it. I’d even be happy with a suggestion as to what material could plug it and withstand the heat. As you could imagine, it sounds like a small tank!

It’s been sitting for a while, I’m out of ideas.

Oh yeah, the best I can offer is a crappy pic I took and a diagram from a catalog showing where the hole is approximately.

Mario

 

[Adrio]

I asked a buddy who has had that engine and done a fair bit of work on it. His reply was:
"EGR valve missing. From memory, a spark plug fits in that hole decently. Or an O2 sensor.

(although from his description it might not.... sounds small... I wonder if the later EGR valves have some plumbing between the valve and the manifold. The original ones just stuck right in)"

I hope that helps.

 

[mylillooker]

Yeah, I think there may be something between the valve and the manifold cause that is too small. But thanks, that's a start.