Plug For Egr Delete

My `85 CJ7 with a 4.2 six cylinder has a tube that goes between the exhaust and intake manifold to supply exhaust gas to the EGR valve. I'm putting on a non-EGR Offenhauser intake manifold but retaining the stock exhaust manifold. I need to plug it where the tube fitting was but it's not standard pipe threads. It appears to be in the neighborhood of 13/16 with a fairly fine thread pitch, maybe 20 (?).

Anyone know exactly what size it is and where I could source one? My local parts stores couldn't help.

I'd rather not drill it out and re-tap to a larger pipe plug and I don't really want to run tube headers either. I guess I could fold the tube shut and weld it up but I don't care for those types of repair measures if I can avoid them.

 

Try a bolt of the correct size and thread pitch or remove tube altogether and braze the hole in the fitting.

 

Possibly the thread is metric. Maybe even 14 mm like a spark plug thread. The exhaust manifold on my 304 has air injection ports that are 14 mm.

 

Were you able to remove the tube without damaging the threads ?

 

The fitting threads were damaged, but not the exhaust manifold threads. So I took the other end out of the intake, without damage, then cut the tube, crimped it shut in my vise and put it in the exhaust manifold for a temporary plug. I wouldn't doubt that it could be metric.

 

Hello! I’m in the same boat, but the other end, and on a 258/4.2! Mine came to me with a stock intake and a header, with the tube missing. I measured it today and it appears to me a 13/16” fine thread as well, though I agree in that time period it was made (1981) it could be metric. I was going to try to find an appropriate plug as well today but ran out of time. I also considered getting something close an JB welding it, though for the exhaust end I am sure it would be too hot. BTW, I removed my EGR and made a block off plate. If you figure it out please post your solution and I’ll do the same.

Thanks

 

if you got the old one out ,weld up the hole in the fitting and thread it back in

 

Been a while but the 304 exhaust manifolds were metric I found some bolts the correct thread and cut them off to plug length. fixed. .

 

I used a Brass compression fitting thread plug on mine . In the plumbing section at any Hardware store Try that for size. ?

 

you wouldn’t happen to remember that size, would you? 22 mm maybe?

 

Been a long time, I think I was tryin misc bolts to try and find something that would fit. when I tried a sparkplug from the 304 motor, fit well. I think those are 14 mm x 1.25 maybe. Be a good starting point anyway.

 

Thanks! I’ll do that.

 

The 258 uses a different way of getting exhaust through the intake than the 304. The 258 uses a tube from the exhaust to the intake. It has been a few years but, I believe I cleaned the best fitting end of the two ends, (cut the tube out) and welded a washer inside of the fitting and then welded the washer shut, screwed it back into the exhaust. It worked for me. The exhaust side fitting size is probably 22mm. If you have a Fastenal store near by would be helpful. The intake side just needs the hole plugged where the EGR was, with a plate or I tapped mine 3/8 pipe tap and screwed a pipe plug into it.

 

Another thought, you could just put a flat metal round piece (like a electrical box knock out) in the hole and tighten the fitting against it. If it leaks, it would be small and wouldn't take long to carbon up. Like on Road kill garage, doing the wrong thing the right way, or something like that.

 

The Jeep came to me without the fitting or tube that goes between the manifolds. I think its a 22mm, seems like a fine thread. Its a bit awkward measuring it as I don’t want to take the manifold off.

 

I know we kinda stole the OP's thread here,(apologies),The OP was asking about the EGR tube on his 232 or 258 six cylinder. And I was talking about a 304 which does not use an EGR tube like the straight 6, the 304 EGR is internal in the cyl head and intake manifold. What I was speaking of is the air injection tube ports that thread into the exhaust manifold at each cylinder. These would probably be a different size fitting and than the EGR tube on the straight six anyway. Point I was trying to make was likely the fittings for anything "emissions" related is likely metric thread.
The air injection ports on the 304 will likely be around 14 mm. And most likely be different size from the EGR tube on the 258.

 

I just pulled mine out and measured it. I get 22mm, 1.5 thread. Although the 18 per inch thread pitch gauge fit better.
My memory is poor. When I pulled it out , I had put a small freeze in the manifold and tightened the original fitting against it. It never leaked. Hope this helps.

 

Thanks! And as said above, apologies for the thread hijack. We now return to our regularly scheduled programming.

 

I need to clarify my last post. I didn't weld a washer in the fitting, I put a small freeze plug in the manifold and and tightened the fitting against it.