I believe it is called a re-circulation pipe.  It connects the right side head to the intake near the carburetor.  It broke while we were taking the motor apart for a partial rebuild.  Does anyone have an extra sitting around they would like to sell me?

 

Looks exactly like this...I need one that isn't broken in two...

 

 

Thanks,

Shawn

AKA, Demon Brat

So, no one has one of these laying around.  I really thought I would put it back on the vehicle with the erg.  I'm I right to think it will run better and get better MPG.  We do not have to pass any test her in Iowa.  

Yeah that's the exhaust gas recirc tube. I have no idea if you can even find those outside of stripping it off of another motor. Best of luck tracking one down man, Between that and the air injection spider tubing on top I took my time getting those off. They look like they're specialty subaru pieces that would be pretty hard to track down --- use a flare nut wrench on the air injection piece!

Seems like it's something that wouldn't be too hard to make. Tubing bender and flare tool should be all you need.

or, swap her over to a weber you'll be glad you did!

We are running a Weber.  I was thinking the pipe we broke is from the EGR which I thought we would keep.

However, I am beginning to think we might ditch the Air Injection System (AIS),  It doesn't seem to provide too much benefit...any thoughts.  How would you guys suggest plugging the four holes from the spider looking AIS?  Can I buy metal plugs to screw in...maybe aluminum... should we use any thread sealant?

 

I think it will really clean up the motor if we lose the AIS.  Passing emissions is not an issue in Iowa.

well then just get rid of the egr, honestly it has no benefits at all 

How do you suggest plugging the hole in the head?

let me take a look at how mine is done, i will get back to you

Remove the pipe from the two threaded pieces and fill the holes by welding or some other means (JB Weld?). Screw them back into position. Could not be any easier and holes will be plugged.

Edited April 30, 201411 yr by Leeroy

^^^ Makes sense. Yours is already snapped anyway...

 

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Let me ask this then, We don't need the recirc tube OR the AIS for these motors? The AIS I thought might help with positive crankcase ventilation, but is that all handled by the breathers on the valve covers then? Any reason to have AIS or the exhaust recirc? I'm curious because my motor is out and less assembly plus a better running motor sounds like a good idea to me. Can someone explain? Thanks.

That is a great question ivsarge.  I am in favor of simplifying the reassembly and the cleaner look as long as it will not effect performance.  Isn't it the PVC valve, the breathers on the valve covers and the air breather's job to ventilate the crackcase.  I thought the AIS only dealt with exhaust gases.

 

If I could come off the valve covers and into the air cleaner that would be a nice look and simple.  Plus the PVC valve.  

 

EGR valve...I thought it helped with MPG?  Thoughts

 

Thanks

EGR helps with mpg on far newer designs that use it beyond lowering combustion chamber temperatures, which is all the early systems were designed to do. Later EGR systems use it to lower pumping losses by filling manifold vacuum with inert exhaust gases.

So much googling and wiki'ing later has brought me to the conclusion that they're both emission control devices, but as described above, the EGR will also lower combustion temps and the sacrifice of some efficiency.

 

AIS helps deliver air to the the exhaust stream to burn off unburnt fuel. Also sounds like it works in tandem with a catalytic converter to bring it up to operating temperature faster. Which of course, I don't have.

I do have a spare EGR pipe if you want it. I also have some EGR valves I cleaned and tested. 

 

I have AIS on my 78 California 4WD Wagon but it doesn't have a cat, the AIS/lined exhaust ports combined with the EGR kept the cars below the limits of the day. 

djcommie,  That would be great.  My EGR valve is good so I would just need the pipe.  I'll send you a message.