if it comes back get the stage 8 locking header bolts, the actually spread out in the head, how far warped was the manifold?

 

Very nice report sir! Glad to hear she's on the road and not leaking. I have a small one that comes and goes as she warms and cool.

 

You filed the manifold? LOL

 

Yes I have done it to multiple units in the past. Not as good as milling, but in a pinch, It knocks the high spots down. I do it to most exhaust manifold sealing surfaces I do, it just knocks off any high spots, burrs, and keeps the sealing surface flat and even. The only thing I did not do that I was going to do was clean the surface where the bolt heads go. I did not touch that, and figure it might cause bolts to loosen, but not sure. I will go for it and hope the rust and what have you don't hurt me too bad.

 

Still no leaks, many hot/cold cycles, should be on the roadto recovery.

 

Hauled boat to lake powell and back this last weekend, 525 or so miles, no leaks. Seems to be a good combo for a fix.

 

6 months in and no leaks, bolts still tight.

 

6 months in and no leaks. Seems tobe the way tofixthis.

 

Resurrection of old thread....

I filed my exhaust manifolds by hand w/ a 12" file and wasn't too pleased with the results for the effort in, so I took it over to my stationary belt sander and let it lightly ride around on that and it worked remarkably well.
Kind of like the old belt type head surfacers.

 

I would not think so. A file on cast iron is a complete waste of time. I just take them to the machine shop to have them decked for $20 a piece when they are not flat

 

Actually, the file was removing material fine. The file was just too small to make manifold plane out in all directions.

I'd bet many machine shops would do an exhaust manifold similarly to how I did it, just with a larger machine:

Sanding exhaust manifold flat:
I used a much smaller machine based on wood working, but it is the same principle.

 

Exactly. You can take material off, but you are not making it flat and that is the whole point of the exercise

 

If you're patient, and don't have a the right power tools, you could tape a large piece of sand paper to a flat surface, then lap the mating surface.

 

I've been using the 7.5 in my farm trucks since the early 90s. I've never had a manifold off that I haven't had resurfaced. A belt sander/planner like is used to flatten aluminum cyl heads works best. Your local automotive machine shop can handle the job. NO gaskets, use only HIGH TEMP silcone, usually red, made for exhaust gasketing. Lok-tite makes it I know. With 3 trucks, one with over 500,000 miles I've never had a leaker. Use high quality bolts, like ones from ARP | The Official Web Site. The locking tab system for header bolts works very very well if you've a recurring problem. Did someone break a bolt off and redrill and tap it? That would be a really good reason for a bolt to loosen. Just do not use a gasket, and plane the manifold. If you EVER have to drill out a bolt, the ONLY way to do it is with a jig from this outfit: https://maniboltdriller.com/. Spendy but I've rented it to several automotive business's around here that deal with that sort of thing. It's awesome and you won't regret purchasing it.

 

Filing is not a waste of time, the machine shops file the long ones that won't fit in their machine, plus you don't necessarily need them flat as much as need them to bolt to the head ports smoothly, so that in mind, do it to set flat on the head, not to set flat on the straight edge. the head needs milled just the same, if everything is to be flat. Next, plane them at ambient temp, the throw in freezer, recheck cold, then throw on wood stove and check hot, and plane (with a draw file) accordingly to mate properly to head ports. It will be way better than the mill job the machine shop does. I have about 6 manifolds from 460s and 429s that are "milled" and never installed on engine, if you cool them, match to head, heat them, match to head, there are gaps from about 0.010"-0.035", reason being head is not "perfect" and manifold changes from hot to cold. Mine were milled in various shops in my area, 3 different machinests and they are flat, and smooth, until they are cold then hot, and then they shift. and move, You take material off as need be to maintain flatness. I will not argue this with anyone, This came directly from 2 30+ year machinists. They said often a flat surface works for a while, but there is better ways. My neighbor is a machinist from 1983 to now. Never done anything else. He knows how meticulous I am and showed me the "right" way to plane manifolds. He won't even do mine on his machine because he knows they will leak in a year or two, so we file, then heat, then take down the high spots, then cool, then take down the high spots, takes about 2 days but the end result is better.