Questions about stock 2f exhaust/intake manifolds (1 Viewer)

[FloTheFJ60]

Making progress on this engine rebuild. Now I’m on to the exhaust/intake setup. Before pulling this motor out always had a leak on the rear horn closest to firewall. Had previously replaced manifold gaskets with the remflex style gaskets but didn’t help much. And also had replaced the j tube egr pipe gasket with same gasket material.

The front horn rotates easily and can be removed without the use of a hammer. The rear horn doesn’t rotate but I can remove with a hammer. I plan on removing the rings and springs and cleaning everything up. I understand the ring gaps need to be offset. Should the horns rotate by hand or should they be tight after reassembly?

The heat riser plate moves freely and the spring action works fine.

If I end up taking the manifold to a machine shop to surface the flanges, I assume they will tack weld the horns into a place. Would I grind off the weld prior to reassembly or leave together as one unit?

Pics of the manifold below. For whatever reason there’s a lot of pitting on the horns in particular. How do these look overall?

Sorry for so many questions. I’ve searched the forums and found answers to some of my questions but still missing key details.

 

[FloTheFJ60]

More pics

 

[FloTheFJ60]

On another note I’m desmogging as well and trying to figure out how to delete the air tube running into the down pipe. I don’t like the option of putting a bolt in the tube and clamping, and hate ruining an otherwise serviceable part but cutting off the tube and welding shut. I assume if I can find a downpipe off an fj40 without smog equipment that would bolt on right?

 

[Spike Strip]

Some machine shops will tack the horn, others don't. Depends on what method of surfacing they use: either on a big belt sander or actually milling the surface. If they tack yours, I would grind it off so it moves, since the engineers designed it that way.

The 'horns' will rotate when not rusted, won't be super-tight, but should be snug. The rings and springs are high-quality stainless and should be reusable, but if they're broken/cracked they were available from Toyota, last I checked.

I hear you on cutting the down pipe Air Inject tube, but 40 pipe will be different, and the Canadian trucks came with a downpipe that did not have that tube, but I've never seen one for sale. Your easiest option will be to weld the bung closed. The downpipe is also high-quality stainless steel. That's why they don't rust. Also check the flange at the manifold side for cracks. Very common.

Never really seen that much pitting on the EX, but doesn't look deep. Ask the machinist.

FJ40Jim sells the best plug for the J-tube, since you're desmoging. LINK

 

[BlackCat]

The horn rings and springs are still available. IIRC, some people mentioned that they only had one ring and spring even though there are 2 notches. Mine has 2 and I replaced them a few years ago. Yes, they should spin and separate as said above with a little effort.

 

[Miloslavich]

The above replies pretty much sum it up. I've done a few of these and for what it's worth, ive never heard of shop tack welding the horns in place.

 

[Mojofilter]

More pics

View attachment 3373050

View attachment 3373051

View attachment 3373052

Making progress on this engine rebuild. Now I’m on to the exhaust/intake setup. Before pulling this motor out always had a leak on the rear horn closest to firewall. Had previously replaced manifold gaskets with the remflex style gaskets but didn’t help much. And also had replaced the j tube egr pipe gasket with same gasket material.

The front horn rotates easily and can be removed without the use of a hammer. The rear horn doesn’t rotate but I can remove with a hammer. I plan on removing the rings and springs and cleaning everything up. I understand the ring gaps need to be offset. Should the horns rotate by hand or should they be tight after reassembly?

The heat riser plate moves freely and the spring action works fine.

If I end up taking the manifold to a machine shop to surface the flanges, I assume they will tack weld the horns into a place. Would I grind off the weld prior to reassembly or leave together as one unit?

Pics of the manifold below. For whatever reason there’s a lot of pitting on the horns in particular. How do these look overall?

Sorry for so many questions. I’ve searched the forums and found answers to some of my questions but still missing key details.

View attachment 3373045

View attachment 3373046

View attachment 3373047

View attachment 3373048

View attachment 3373049

FlotheFJ60: I've got one of these that's in much better shape. I could send pics if you want...