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- #61
That you did & it went completely unnoticed by me.
New (old) addition to the stable
- Thread starter S.CarolinaFZJ80
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- Thread starter
- #62
@roadstr6
Well can o' worms was officially opened by trying to fix exhaust... exhaust manifolds have warped ever so slighty after being installed for 38 years. Need to get it machined. Which machine shop did you use to deck yours?
Well can o' worms was officially opened by trying to fix exhaust... exhaust manifolds have warped ever so slighty after being installed for 38 years. Need to get it machined. Which machine shop did you use to deck yours?
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Quality Auto Machine in Monroe. Before you take it to them, check the intake manifold to make sure there is not a crack directly under where the carb sits.
If there's not a crack (not even a hairline) you're good. Take it on in for machining. If you have a crack, you may want to either have someone weld it up or purchase a heat riser block-off plate that goes under the intake manifold between the I & E. The plate requires the I & E to be separated, so you would want to have the machining done after you put it back together, not before. Does that make sense?
There is a flap in the exhaust manifold that, when cold, opens up to direct exhaust heat to the intake to help it warm up faster. It is supposed to close when it warms up. Sometimes it can hang up and continue blasting the intake with hot exhaust, causing the crack. The block-off plate does two things, it stops the exhaust from hitting the intake and it seals up the crack (which is nothing but a huge vacuum leak). Hopefully it won't be an issue with your truck. It's a hit and miss thing, especially with 60's. I think with 40's, not so much, but better safe than sorry, especially when you are already this deep into it.
If there's not a crack (not even a hairline) you're good. Take it on in for machining. If you have a crack, you may want to either have someone weld it up or purchase a heat riser block-off plate that goes under the intake manifold between the I & E. The plate requires the I & E to be separated, so you would want to have the machining done after you put it back together, not before. Does that make sense?
There is a flap in the exhaust manifold that, when cold, opens up to direct exhaust heat to the intake to help it warm up faster. It is supposed to close when it warms up. Sometimes it can hang up and continue blasting the intake with hot exhaust, causing the crack. The block-off plate does two things, it stops the exhaust from hitting the intake and it seals up the crack (which is nothing but a huge vacuum leak). Hopefully it won't be an issue with your truck. It's a hit and miss thing, especially with 60's. I think with 40's, not so much, but better safe than sorry, especially when you are already this deep into it.
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- #64
As far as the exhaust goes, the manifold is leaking from the junctions of all three pieces. Hmmm, might be cheaper to do headers than to rework this one.
Careful. Headers have a terrible reputation with head sealing issues. It seems that many of them are crooked right out of the box. Find a good set of manifolds and have them machined. I think I spied a decent set in @Roxx cruiser graveyard. Maybe see if he will let them go.
Double check that what you are calling a crack is not just casting flash. Turn the intake over and look for a crack underneath. You will need to clean off the soot on the underside to verify.
You can buy new sealing rings for the exhaust end horns. They are not too terrible. Same goes for the intake / exhaust junction.
Double check that what you are calling a crack is not just casting flash. Turn the intake over and look for a crack underneath. You will need to clean off the soot on the underside to verify.
You can buy new sealing rings for the exhaust end horns. They are not too terrible. Same goes for the intake / exhaust junction.
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- Thread starter
- #66
I'm on OEM Toyota Parts Online | Village Toyota Parts
right now looking at the parts diagrams seeing what is still available.
right now looking at the parts diagrams seeing what is still available.
Agree on header comments.
Another option you may consider is the 3fe manifolds. Almost a mini factory header. I went this way when i rebuilt the 2F in the 55. A little but of extra machining but its already gonna be at the shop.
You have to counter sink the bores in the flange to make them even width as the intake flange to get a good even clamp on both.
Also. Remflex gasket is pricey but worth it IMO
Another option you may consider is the 3fe manifolds. Almost a mini factory header. I went this way when i rebuilt the 2F in the 55. A little but of extra machining but its already gonna be at the shop.
You have to counter sink the bores in the flange to make them even width as the intake flange to get a good even clamp on both.
Also. Remflex gasket is pricey but worth it IMO
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- #68
You have convinced me against the header option.
What I perceived as warpage was just a slight rotation of the horns combined with left over gasket material.
Now to obtain all of the various gaskets, nuts, bolts and washers.
I have the schematics and good idea of the parts needed now I need a good vendor. @beno
Depending on millwork cost and hours involved, it might be a break even to just get the whole new manifold assembly from Toyota. It shows still available?!?!
What I perceived as warpage was just a slight rotation of the horns combined with left over gasket material.
Now to obtain all of the various gaskets, nuts, bolts and washers.
I have the schematics and good idea of the parts needed now I need a good vendor. @beno
Depending on millwork cost and hours involved, it might be a break even to just get the whole new manifold assembly from Toyota. It shows still available?!?!
If i were you i will not do header. Everyone that i know that does it. Wishes they never change it. And everyone that buys a truck with one, want to get it back to specs
Yeah, those horns do rotate and will actually pull loose from the center of the manifold. Some say to tack weld the horns in place before having it planed (which makes sense) and then cut the tacks before you install. I didn't do that and it still worked out fine for me. I'd be surprised if the manifolds are still available, but no worry. Good used ones are available for cheap. Maybe post a Wanted ad in the classifieds. Like I said before, I'm pretty sure I spotted a good one (not cracked)in Rafael's parts heap. It may have been for an F though. Not sure. It was in his trailer.
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- #73
Wow! That's an interesting "circus" themed motor!
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- #74
That Toyota parts site I posted above showed them as still in stock and not NLA. I'll have to dig into that more.
That 3FE header looks like a great plan too. I'll look into that more but in the meanwhile, trying to get this 40 back on the road sooner rather than later...
Seeing as their is a gasket ring and spring attaching each horn, I'm wondering if they should all be replaced (as they are leaking) before milling the gasket surface OR mill first then bead blast remove horns, blast a bit more then reinstall with new rings and springs.
Doesn't work that way with the 3FE manifolds. The 2F exhaust manifold bolts to the intake manifold, allowing you to machine as one unit, but the 3FE manifold does not bolt to the 2F intake manifold to allow this.
The point though is that the thickness of the manifolds (intake and exhaust) where the shared bolts meet need to be as close to the same as possible. This allows the shared bolts to put equal pressure on the intake and exhaust manifolds. People neglect to check this when installing headers, which is why people have so many issues with headers, but the same will happen with 3FE manifolds unless checked.
If you are doing the 2F manifolds, take the horns off, bead blast, reassemble everything and then have it planed. That's what I would do. I don't have experience with the 3FE pieces other than to say that those who have gone that route say it is worth the extra trouble to do.
It can happen on the 2F manifolds too. I believe there is already a slight difference in flange thickness between the intake and exhaust manifolds. If the manifolds are warped and you have them planed, you can end up with hugely different flange thicknesses. They'll be flat on the head side but not where the bolts snug to the manifolds. I have always heard of the process of making the mount points equal as "spot facing." I did not do this with my 2F manifolds and I wish I had. It took a lot of fiddling with shims and such to get everything to bolt up nice and even.
100%, absolutely it can, but usually to a much smaller degree because the 2F exhaust manifold bolts to the intake. Last set of 2F headers I installed I had to weld washers onto the header and sand them down to get the thickness right. Was about .125" out when I started.
Agree about the 3fe as i did a set but not what i was referring to. Sounded like he was bailing on the 3fe manifolds for now (although it would be no more delay than finding a set @NCFJ maybe).
Simply meant he didnt want to plane the surface then go monkeying with it and changing gaskets and potentially the angle of end pieces.
Simply meant he didnt want to plane the surface then go monkeying with it and changing gaskets and potentially the angle of end pieces.