Heater hose ports on head?

[ngsd]

I have three Broncos with 302's and this one I just got has a heater hose fitting that looks like it was bypassed and runs from this plug on the right front head to the left rear head. What are these for? Smog? The others don't have this. I assume this was part of the smog but just have not seen these before on my other 74 and 76. Next question is are they leaving a vacuum if left open? I assume so but they are rotted and not sure how to remove them. One has a bolt head and the other doesn't.

 

[ngsd]

Looks like I see what these are. Thermactor air injection? Now what to do with removing the one with a broken bolt in the back of the engine....

https://classicbroncos.com/forums/showthread.php?t=274918

 

[Steve83]

The one without a bolt should twist & come off. See what happens removing the one WITH the bolt.

Does 9B448 in this diagram look like what you've got?

(phone app link)

 

[ngsd]

Yes it is

 

[tirewater]

If you don't need them, remove them and block off the holes. They result in an exhaust leak, in addition to being noisy when not closed off.

Use a bolt and fender washer with some orange high temp sealant to block it off.

 

[ngsd]

Thanks, I think i understand this now. Just need to dive in and see how to get that broken bolt out on the back one. It of course is in the back under the brake booster and hard to get to. I would assume it broke off and will not come out so drilling it in place should be fun.

 

[pcf_mark]

Maybe it is a plug and not a broken bolt?

 

[ngsd]

Maybe it is a plug and not a broken bolt?

The valve fitting remains with no bolt head. I have a camera on it but cannot tell if the hole is filled or if the hole has the remains of a broken bolt. I am assuming at this point that the valve without a bolt head suggests that the head broke off while trying to remove it but that is only an assumption until i get a hammer on it tonight to see if it falls off like the other did with a couple taps. Then how I remove the bolt remains if they are there would be the next challenge in this location. I will hopefully find out more tonight when I tackle this after work. Thanks for the replies, you guys are helpful.

 

[SHX669]

It's been quite a while since I plugged one but i think that's a pipe thread - tapered . I used a "flush " plug with an Allen head .

 

[Steve83]

Soak it with penetrant for a few days before drilling - it may come loose.

 

[ngsd]

The one without a bolt should twist & come off. See what happens removing the one WITH the bolt.

Does 9B448 in this diagram look like what you've got?

(phone app link)

The one with the bolt head came out easily and I see how I can use a bolt, washer and sealant possibly. Cant get the back one off yet and will give it another try tonight

 

[Steve83]

Post well-lit focused pics of the one that came off so we can see how it's built.

 

[Rustytruck]

Measure the size fronm the part you took off. Use a welch / freeze plug to plug the hole. can drill a hole in the middle for a short bolt. If memory serves me its a 7/8" size but measure it and be sure. Napa use to carry different sizes of Welch plugs.