Engine Air Tube On Head Problem

[7991LXnSHO]

I am restoring missing emissions equipment and have encountered a problem. I assume the biggest of the two holes on the back corner of the heads should be threaded and actually allow air to go somewhere. It is threaded, but it seems to go nowhere. It is right next to what looks like a quarter inch threaded hole. I expected a pipe plug, a bolt or an Allen headed plug. Instead, it looks like the threaded hole never went anywhere. The other heads that came from the same previous owner seem to have the same deal - no obvious hole or plug at the bottom of the threads. There is just iron or steel at the base of the deep bolt hole. I have uploaded a picture of a mirror aimed at back of the passenger corner of the passenger head so you can see too. Is there a plug that is threaded inside that could be removed with a BIG flat screwdriver bit?

 

[ratio411]

It appears to have a plug in it.
Like you say, the plug is made to be removed with a big screw driver.
The plug is threaded, I would assume, in case the head is ever swapped around and that hole is needed for accessory mounting.
I just plug them with a very short bolt of correct threads, but they do sell the plugs threaded like what you have.
In stock use, the smaller holes to the side will hold the pipe on to the head, going through a 'block' of metal at the end of the pipe.

 

[ratio411]

Here is the stock plumbing on a truck 5.0.
The car setup is very similar, and bolts to the heads the same way...

 

[ratio411]

Here is the plug:

 

[7991LXnSHO]

Here is the stock plumbing on a truck 5.0.
The car setup is very similar, and bolts to the heads the same way...

Good pic. The tube ends look exactly like this, the backflow valve is down on the passenger side when it is in the car. I also see the packs of 4 plugs in Jegs. For some reason I did NOT expect the center to be threaded, so I thought I would ask.
So as far as getting them out, my firewall is in the way of using my big screwdriver. I am thinking of the best tool to use in the small space I have behind the engine. It would need to be fatter than any regular flat bit from the hardware store. QUESTION 1. So what would you use to make a slotted bit from? QUESTION 2. I am also thinking about putting a bolt in the middle of the plug with a nut on it. Then I might be able to tighten up the nut against the plug and turn out the bolt and plug? If I grind a taper on the end of the nut so it would contact the plug insert and not the head, is this a good idea? RELATED QUESTION 3. Is there a better tool idea (besides leaving smog stuff off) to get this working? I plan on using Liquid Wrench or P'Blaster first too. Thanks!

 

[ratio411]

You might try the jamb nut method... However, I believe those are going to be a bear to remove in the car.
Soak them in nut blaster and put a jamb nut on a bolt and see what happens.
The worst that could happen is you break the bolt off, but they'll still be plugged if you do.
At that point, if you want them gone, the head has to come off, but I think that will be the case no matter what.
Good luck!

 

[7991LXnSHO]

Ever change a rear sprocket cluster on a 10 or 12 speed? It seems I will have the same trouble either way, on or off the motor, in or out of the car; the darn plugs are in instead of a bolt. So I will practice on my spare heads, but I will make a different tool. If I use grade 8 hardware, I hope it will reduce the chance of breaking off. This picture was swiped from an online auction site, but shows what I am thinking about grinding and filing for teeth. I hope I can make something with teeth like this for the slots in the plugs, bolt it on, then spin the part with teeth, and hope it all comes out.
If that does not work, what am I to do? Take off the head, drill out the center, use heat and an "easy out"? If the heads have to come off, I am tempted to put new ones on if the block's compression is good.

 

[7991LXnSHO]

Time for plan B. The tool I made grabbed well enough to bend the teeth but not remove the plug, and the loctite did nothing. I no longer see the plugs coming out with the heads on the car. So, I want to find another way to run cats.

There are two valves on this car, one to send air to the heads and one directly to the cats.If I put a T in the vac line and have both signals run the valve that sends pumped air into the cats, it should still spit a code. But will the cats be happy with the air that way?

 

[7991LXnSHO]

Was my emissions related question too esoteric? Is this a good solution until I get aftermarket heads? Is jrichker or another emissions expert there? I really want to use the x pipe I bought.

 

[Hawkeye_306]

I'm NOT AN EXPERT, but this is what I've been told (for what it's worth)... the crossover tube is part of the thermactor system & is used to supply air to the exhaust upstream of the cats (via ports in heads) during warmup to help speed heat up of cats & O2 sensors, then after a few mins, valve switches to send 100% of air directly to cats to help chemical process that reduces NOx reduction...If that's the case, having the head ports blocked wouldn't seem that big of a deal. Again, I'm not 100% if that's correct, but seeing as how you haven't got an answer yet, figured I'd share what I know in case it gives you a clue as to where to look next.

As far as removing the plugs (with the heads off) thread in a bolt, heat it cherry red, then smack it straight on ~5 times with a hammer. Remove the bolt, let it cool, then try removing plugs. Repeat if necessary.

Come to think of it, if you take the heads off, could simply drill through the plugs to "make a passage" & save some sweat.

 

[7991LXnSHO]

Thanks for a non snack chip answer! Youf thoughts are what I was hoping to hear. I would beat on a bolt placed in the insert while the heads are in the car, but I like my AC tubes to not have holes in them. There is just too much in harm's way. Same problem for a right angle drill attachment while the heads are in the car.