FE exhaust manifolds

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Mojave922
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FE exhaust manifolds

Post by Mojave922 »

I recently bought a running 390 out of a '62 tbird to replace a tired 352 and noticed that the exhaust manifolds are different where they meet the exhaust pipe. The 390 manifold has a flat surface and a gasket while the 352 uses a ceramic donut to make a seal. I'd swap the manifolds to utilize the current pipes but I'm afraid of breaking the bolts off in the newly acquired 390, after doing just that on my 352. I made ill-advised use of an air tool and no penetrating oil and sheered off five or so of the bolts in the head. Oops.

Can the flat styled manifolds be relied on to seal? The got to hear the engine run before buying and it had a very noticeable exhaust leak from rear passenger side of the motor. I wasn't able to put a gloved hand on the exhaust to see where the leak was coming from, but is the junction between manifold and exhaust most likely where the leak was, as opposed to between the manifold and head?

Was hoping to re-use the existing exhaust pipes to save some $$ but pay for new pipes before risking broken exhaust bolts again. Thanks in advance for any advice and words of wisdom.
David

65 F100 swb (352 3 spd manual, not running)

Previous rides:
69 Bronco, completed frame-off restoration
07 Kawasaki KLR650
92 Acura Integra GSR
65 Mustang 2+2 A-code
67 Mustang coupe C-code
64 f100
Posts: 2754
Joined: July 18, 2006, 7:23 am
Location: Carmi, Illinois, 62821

Re: FE exhaust manifolds

Post by 64 f100 »

Without looking at your motor, I cannot give you really good advice on how to remove the exhaust bolts. Mainly it's a matter of seeing how long the engine has not been touched and the bolts removed in the past. Hopefully, the engine is still out where you can get at it and look closely at the bolts on top of the manifolds. These are usually the ones you have a problem with as these bolts go thru the flanges and are open to the air. Lack of good sense from PO's in not using a good antisieze to help prevent seizing . I suggest you don't install the motor until you have this problem addressed. I also am wondering about your choice of engine, as there were mounting differences from early 390's to later 390's. The engine may work fine, but without looking it up in my junkyard bible I don't know. At one time, I may have had this info, but at 70 some things have slipped away on me. A few suggestions on the manifold bolts might be of use to you, but use my suggestions as only suggestions, not as the only way to do the removal of the manifold bolts.
Heat can be your friend and or your enemy. I would first try soaking the bolts down with something like PB blaster every day for a few days. Then using a socket and ratchet, try to loosen the bolts. Working the bolts forward and backward with plenty of PB blaster. If you can get the bolts to break loose , then you have pretty much got the problem taken care of, but don't use an impact wrench even after the bolts have come loose. Work the bolts out don't try and force things. A lot depends on whether the bolts are sticking out the back side of the head flanges, as these parts are exposed to water and air causing excessive rust on the bolts where exposed to the weather. If unable to break the bolts loose with this technic, you may need to heat the flange area of the bolts on top row one at a time. Since you most likely will have soaked it with whatever in the hope that the bolts will come loose, you might want to have a fire extinguisher handy or at least a bucket of water. You will need enough heat to get the flange to a red color around the bolt , at least on and around the side you can see. The bottom bolts are not exposed to weather and usually come out without to much trouble. When done, be sure to use a tap and clean up all threads, and clean out the bolt holes in the manifolds, as these have a tendency to become filled with rust and can also be a leading cause of not being able to remove the bolts. I take a drill bit the size of the holes and run it thru the manifold holes to clean those up. I also suggest that whatever else you do, choose the bolts to go back in the upper holes in a length that does not go all the way thru the flanges on the head. I try to make sure those bolts stop at or barely above or below the hole. Stainless may be the way to go, but I do not know that for a fact, just a thought. As to the leakage problem, you should be able to inspect the manifolds and gaskets once off to see where the leakage is. Pitting between the manifolds and heads is sometimes found, and there is only one actual cure for that and that is to machine the surface's, but a new gasket and high temp RTV also can work and is a lot less expensive.
There is a technic used on motorcycle aluminum cases, but I would certainly be careful of trying to use it in this instance. Before trying to loosen a bolt screwed into the aluminum, you give it a sharp rap on the end. This helps break the bonding that has developed overtime between the aluminum and steel of the bolts, making it easier to remove the bolts. I only mention this as a last resort, as you can break the flange off the head if not careful, but may help break the rust loose a little. A lot depends on how rusty everything is as to what way I would go. If, you don't have the engine in the truck, now is the time to fix the problem, where it is easy to get to. If the engine is in, I suggest you take it back out to do this work. This is not something you want to tackle with the engine in the truck.
One other thought, I suggested using a ratchet and not a breakover bar. I suggested this as it will help to keep you from using excessive force, although in my younger days I used to break off head bolts with the 3/8th's ratchet and you can break these bolts with the 1/2 inch drive easily. I often try and tighten the bolts if these will not break loose easily. If you can move the bolt either way, you have half the battle won.
Once I have determined PB blaster is not going to work, then I usually go the hot wrench way. If the bolt does not break loose then, I wonder if the bolt is seized in the manifold from rust which will stop the force you are applying to get to the threads of the bolt in the head. At the point where I decide the rust in the hole in the manifold is the problem, I have a decision to make. Whether to cut the head off or possibly drill it to be able to break the head off leaving enough of the bolt sticking out of the head to either weld a nut or something to the bolt and try to remove it, or try vice grips at that point. Welding a nut to the stud sticking out of the head has the advantage of heating things up also.
One other option that might help, is to heat the flange some, not red, and spray the blaster on the area where the flange and threads meet on the top side. This cools the bolt and flange and hopefully will cause some of the blaster to be sucked into the affected area.
slick4x4
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Re: FE exhaust manifolds

Post by slick4x4 »

Years ago we had to pull the manifolds off of an engine
Snapped the first 2 we tried :cussing:
I cut the rest of the bolts heads off with a torch
Pulled the manifold
And then when I went to remove the bolts
I'll never forget ....
We screwed ALL the bolts out... With our fingers !
.
.
.
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unibody madness
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Re: FE exhaust manifolds

Post by unibody madness »

I worked on marine cranes built in the late fourties that sat over salt water and often was unable to remove/loosen bolts/pins or snapped them off.
We found an old can of Kroil oil, let the part sit for at least half an hour after application and often needed minimal force to unstick the stuck. The heat methods worked much better after that.
Kroil is still available in most hardware stores in an orange and black can.
Turk build thread at:
viewtopic.php?f=32&t=18944

It does not matter what you think, it only matters what you do about it!
chris401
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Re: FE exhaust manifolds

Post by chris401 »

If your exhaust is built with truck log manifolds you will need to reuse them. The 62 car exhaust flange has many differences from the trucks. If the threads are exposed on the head side you risk cracking the ear when you unscrew them. If it comes to forcing them out using the methods posted above you probably be better off blowing them out with a torch. Keep the heat on the broken bolt and in line with it you'll be fine.
Chris
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Mojave922
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Joined: June 4, 2016, 11:24 pm
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Re: FE exhaust manifolds

Post by Mojave922 »

64 f100 wrote:Without looking at your motor, I cannot give you really good advice on how to remove the exhaust bolts. Mainly it's a matter of seeing how long the engine has not been touched and the bolts removed in the past. Hopefully, the engine is still out where you can get at it and look closely at the bolts on top of the manifolds. These are usually the ones you have a problem with as these bolts go thru the flanges and are open to the air. Lack of good sense from PO's in not using a good antisieze to help prevent seizing . I suggest you don't install the motor until you have this problem addressed. I also am wondering about your choice of engine, as there were mounting differences from early 390's to later 390's. The engine may work fine, but without looking it up in my junkyard bible I don't know. At one time, I may have had this info, but at 70 some things have slipped away on me. A few suggestions on the manifold bolts might be of use to you, but use my suggestions as only suggestions, not as the only way to do the removal of the manifold bolts.
Heat can be your friend and or your enemy. I would first try soaking the bolts down with something like PB blaster every day for a few days. Then using a socket and ratchet, try to loosen the bolts. Working the bolts forward and backward with plenty of PB blaster. If you can get the bolts to break loose , then you have pretty much got the problem taken care of, but don't use an impact wrench even after the bolts have come loose. Work the bolts out don't try and force things. A lot depends on whether the bolts are sticking out the back side of the head flanges, as these parts are exposed to water and air causing excessive rust on the bolts where exposed to the weather. If unable to break the bolts loose with this technic, you may need to heat the flange area of the bolts on top row one at a time. Since you most likely will have soaked it with whatever in the hope that the bolts will come loose, you might want to have a fire extinguisher handy or at least a bucket of water. You will need enough heat to get the flange to a red color around the bolt , at least on and around the side you can see. The bottom bolts are not exposed to weather and usually come out without to much trouble. When done, be sure to use a tap and clean up all threads, and clean out the bolt holes in the manifolds, as these have a tendency to become filled with rust and can also be a leading cause of not being able to remove the bolts. I take a drill bit the size of the holes and run it thru the manifold holes to clean those up. I also suggest that whatever else you do, choose the bolts to go back in the upper holes in a length that does not go all the way thru the flanges on the head. I try to make sure those bolts stop at or barely above or below the hole. Stainless may be the way to go, but I do not know that for a fact, just a thought. As to the leakage problem, you should be able to inspect the manifolds and gaskets once off to see where the leakage is. Pitting between the manifolds and heads is sometimes found, and there is only one actual cure for that and that is to machine the surface's, but a new gasket and high temp RTV also can work and is a lot less expensive.
There is a technic used on motorcycle aluminum cases, but I would certainly be careful of trying to use it in this instance. Before trying to loosen a bolt screwed into the aluminum, you give it a sharp rap on the end. This helps break the bonding that has developed overtime between the aluminum and steel of the bolts, making it easier to remove the bolts. I only mention this as a last resort, as you can break the flange off the head if not careful, but may help break the rust loose a little. A lot depends on how rusty everything is as to what way I would go. If, you don't have the engine in the truck, now is the time to fix the problem, where it is easy to get to. If the engine is in, I suggest you take it back out to do this work. This is not something you want to tackle with the engine in the truck.
One other thought, I suggested using a ratchet and not a breakover bar. I suggested this as it will help to keep you from using excessive force, although in my younger days I used to break off head bolts with the 3/8th's ratchet and you can break these bolts with the 1/2 inch drive easily. I often try and tighten the bolts if these will not break loose easily. If you can move the bolt either way, you have half the battle won.
Once I have determined PB blaster is not going to work, then I usually go the hot wrench way. If the bolt does not break loose then, I wonder if the bolt is seized in the manifold from rust which will stop the force you are applying to get to the threads of the bolt in the head. At the point where I decide the rust in the hole in the manifold is the problem, I have a decision to make. Whether to cut the head off or possibly drill it to be able to break the head off leaving enough of the bolt sticking out of the head to either weld a nut or something to the bolt and try to remove it, or try vice grips at that point. Welding a nut to the stud sticking out of the head has the advantage of heating things up also.
One other option that might help, is to heat the flange some, not red, and spray the blaster on the area where the flange and threads meet on the top side. This cools the bolt and flange and hopefully will cause some of the blaster to be sucked into the affected area.
I haven't pulled the motor mounts off of the 390 yet. Sure hope the 352 mounts will work on it!
David

65 F100 swb (352 3 spd manual, not running)

Previous rides:
69 Bronco, completed frame-off restoration
07 Kawasaki KLR650
92 Acura Integra GSR
65 Mustang 2+2 A-code
67 Mustang coupe C-code
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6166 Junkyard Dog
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Re: FE exhaust manifolds

Post by 6166 Junkyard Dog »

ON The FE'S The top 4 bolts we have used a black/silver can of WD-40 that is marked professional grade and have had 100% success rate so far on 16 bolts so far
Tom,
@
Lazy FORD Ranch
Where Ford Trucks Rest in Peace

Dakota,,, RIP will never be the same looking for 61-66 trucks again ,, :cry: Kathy :cry:
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