1977 CA Exhaust - what is this part? (1 Viewer)

[majdomo]

Looking for anyone who may know what this part is, with the paint marker and the weird nubbin in the middle. I can’t de-smog the thing (CA) but need to figure out how to seal off an exhaust leak here. Also noticing a small crack there, not sure if it’s leaking there as well, will have to recheck.

Small paint marks up above to mark additional leaks, however the bolts were loose here so that may have done it.

Any ideas welcome, thanks!

 

[Pin_Head]

I had a couple of those “thermonuclear reactor” manifolds, but I don’t remember seeing that screw / flange gizmo. They are notorious for cracking and leaking. Brazing the cracks and leaks works, but it may keep cracking. You should be able to substitute a later manifold since they are NLA as long as it has the EGR connection If you want to throw in the towel.

 

[majdomo]

I had a couple of those “thermonuclear reactor” manifolds, but I don’t remember seeing that screw / flange gizmo. They are notorious for cracking and leaking. Brazing the cracks and leaks works, but it may keep cracking. You should be able to substitute a later manifold since they are NLA as long as it has the EGR connection If you want to throw in the towel.

Thanks Pinhead. Doing more research, looks like @gonzopancho is making progress on a CARB-compliant version of the old Downey headers (by way of @65swb45), which could be the way to go. It passes smog as it is but gives me some farty backfires on shutdown and ticky-ticking on the freeway under load.

I also found many, many exhaust leaks up and down the rest of the exhaust. It’s a holey mess as it is, but not that concerned about those since I‘m planning to have the whole thing redone at some point. This is the only part that is not easily replaced.

 

[majdomo]

Did another leak test on the manifold tonight, and it’s full of cracks. The soapy water foamed up like crazy in all sorts of spots with the exhaust under positive pressure. Guess I’m in the market for a federal manifold or some CARB-compliant headers...

 

[ToyotaMatt]

Looking for anyone who may know what this part is, with the paint marker and the weird nubbin in the middle. I can’t de-smog the thing (CA) but need to figure out how to seal off an exhaust leak here. Also noticing a small crack there, not sure if it’s leaking there as well, will have to recheck.

Small paint marks up above to mark additional leaks, however the bolts were loose here so that may have done it.

Any ideas welcome, thanks!

View attachment 3056783

i think its a bi-metalic spring / shaft rotate port of some kind like a heat riser on a FEDERAL emissions 2F same year 1977 ?

I had a couple of those “thermonuclear reactor” manifolds, but I don’t remember seeing that screw / flange gizmo. They are notorious for cracking and leaking. Brazing the cracks and leaks works, but it may keep cracking. You should be able to substitute a later manifold since they are NLA as long as it has the EGR connection If you want to throw in the towel.

 

[sggoat]

I had some of these same issues with my 77 years ago(ca spec)--All the issues went away when I installed the headers(JT outfitters)--stopped the vapor lock--with a remflex gasket--no leaks(but I did have the intake/header flanges milled to the same thickness)--running constant vac at 24" at idle---but I'm in Fla, so the emissions are not as stringent---can't wait for the gonzopancho/Marks new effort----

 

[majdomo]

Ended up with a FED-spec manifold from Mark’s Off Road and an entirely new exhaust. That, and a ton of additional work after blowing out the head gasket. Vacuum leaks solved, pretty sure anyway!