8N manifold

dhammel01

New User
I'm replacing gaskets on head and manifold on 8N. I've found that the exhaust/intake manifold is rough and pitted on two ports. See photo.
It almost looks like this has been welded - but that would be impossible / improbable - correct? The rough area is not left over gasket - it is entirely pitted metal.

The gasket came off this area is bits and pieces - so this has been a bad - leaky area for awhile evidently.

Is it necessary / advisable to have a manifold machined? Is it necessary considering that there's not compression as there is on the head?
Should I just scrap / sand / file this down as much as possible and will a new gasket then seal this up?


cvphoto53190.jpg
 
(quoted from post at 12:25:29 08/14/20) I'm replacing gaskets on head and manifold on 8N. I've found that the exhaust/intake manifold is rough and pitted on two ports. See photo.
It almost looks like this has been welded - but that would be impossible / improbable - correct? The rough area is not left over gasket - it is entirely pitted metal.

The gasket came off this area is bits and pieces - so this has been a bad - leaky area for awhile evidently.

Is it necessary / advisable to have a manifold machined? Is it necessary considering that there's not compression as there is on the head?
Should I just scrap / sand / file this down as much as possible and will a new gasket then seal this up?


<img src="https://www.yesterdaystractors.com/cvphotos/cvphoto53190.jpg">
here is a product called Remflex. I recomend them to anyone running headers. If they make your gasket you won't likely ever have another leak. That surface will seat right into the gasket and seal.
 
Agreed. My old manifold was cracked and re-welded out of alignment. I have my own mill and could have, without too much effort, machined it myself except that a new manifold was too cheap to resist.
 

That's about how my old manifold looked at #4 cylinder. The block was ok. I didn't even bother thinking about repairing it. New manifolds are not that expensive.
 
I would follow Bruce's response, but I would fix the manifold in the same manner as the block.
When I bought our 8N, ( nickname:The Junk Pile) it had the same issue.
I cleaned and acid etched both surfaces.
Then I made a plywood section that I could bolt to the block and one that I could bolt to the manifold.
I mixed up the 2 part ceramic-epoxy, brushed it on the areas, placed a sheet of aluminum foil over the area and the bolted the plywood section to each side tightly to mold the epoxy flat on each side.
That was 8 years ago. No exhaust leaks since.
 
No, no, no on all your questions. The hottest area is at cylinder #4 port and once cancer sets in, it's time to just replace the manifold as Bruce said. I advise against trying to weld and apply a band-aid. You've done the hard part -removing all the parts - so dig into your pockets and invest a whole new manifold, you won't be sorry. Why waste time and money on a "temporary fix" and then have to go thru the entire repair job all over a few weeks, months later? Get the Essential Manuals for the procedure. Get: New manifold and 3-gaskets kit; new muffler clamp; new muffler if it's due; bottle jack and block of wood to position the new exhaust pipe to manifold with; new rubber air cleaner hoses if old are hardened and/or leaking; new hose clamps; new sets of 4 7/16-20 Brass Hex Nuts and steel lockwashers for manifold assembly to block -they sell in a kit. Torque brass nuts to 27 FT/LBS. Know how to properly apply torque? It's done in three steps. I also advise to drain some coolant from radiator petcock first, manifold to block studs often will come out upon removal, but you may have found that out already. Two paper gaskets on manifold to block -one on each side, not doubled up, and one paper gasket on manifold to carb, no Permatex needed. Assembly new manifold first with new muffler. When secure, fasten the carb and air cleaner. Run tractor a few times then check the torque again a few weeks later and adjust if needed.

FORD 8N TRACTOR ESSENTIAL OWNER/OPERATOR/PARTS/SERVICE MANUALS:
qI9P22kh.jpg



Tim Daley(MI)
 
You've gotten good advice, but to answer some of your questions:

I've found that the exhaust/intake manifold is rough and pitted on two ports....
It almost looks like this has been welded - but that would be impossible / improbable - correct?

No, not impossible, but your's has not been welded.

..... it is entirely pitted metal.
...... this has been a bad - leaky area for awhile evidently.

Yes. That's why it's pitted. Block may show some too.

Is it necessary / advisable to have a manifold machined? Is it necessary considering that there's not compression as there is on the head?
Should I just scrap / sand / file this down as much as possible and will a new gasket then seal this up?

Shave or replace as said, or this erosion will \ most likely continue. (see note above about affecting cylinder block)
 
(quoted from post at 12:25:29 08/14/20) I'm replacing gaskets on head and manifold on 8N. I've found that the exhaust/intake manifold is rough and pitted on two ports. See photo.
It almost looks like this has been welded - but that would be impossible / improbable - correct? The rough area is not left over gasket - it is entirely pitted metal.

The gasket came off this area is bits and pieces - so this has been a bad - leaky area for awhile evidently.

Is it necessary / advisable to have a manifold machined? Is it necessary considering that there's not compression as there is on the head?
Should I just scrap / sand / file this down as much as possible and will a new gasket then seal this up?

Consider yourself lucky that the same area on the block is not all eroded and just buy a new manifold and be done with it.

However, when mine was eroded and leaking like that, I could hear the leak. It sound like a loud ticking sound and if I put my fingers around that area with it running, I could actually feel the escaping exhaust. I'm really surprised you didn't hear anything.

It all depends on how long you want to mess around with it. But, like I said, a new manifold will put an end to the problem.
 
Thank you all for the good information. I can always count on this crew!

New manifold is ordered. Fingers crossed that it fits reasonably well.

Funny story - I was at my local implement dealer (Rushford Minnesota) getting the gaskets - and I commented that perhaps it was time to think about one of those fancy Kubota or John Deere tractors. My new - old pal behind the counter laughed and said - no, that wont happen, I've see this condition all the time. You're pass the point of no return with an old tractor. You're a lifer at this point.

So here's to all you - us - lifers. Cheers!!
 
(quoted from post at 10:23:25 08/15/20) Thank you all for the good information. I can always count on this crew!

New manifold is ordered. Fingers crossed that it fits reasonably well.

Funny story - I was at my local implement dealer (Rushford Minnesota) getting the gaskets - and I commented that perhaps it was time to think about one of those fancy Kubota or John Deere tractors. My new - old pal behind the counter laughed and said - no, that wont happen, I've see this condition all the time. You're pass the point of no return with an old tractor. You're a lifer at this point.

So here's to all you - us - lifers. Cheers!!

One word of caution. When you go to install that new manifold, put it on the studs dry and make sure you can get all the nuts on. Sometimes the clearance for the bolts isn't enough. The last manifold I put on, I had to remove it again and take a Dremel tool with a grinder on it and remove some excess material for the nut clearance. Also remember that you have to have enough room around that nut to get a socket on it.

It's not really a big problem unless you install your gasket with some kind of gasket sealer on it and then find out you have to grind out around those openings for socket clearance. I was lucky in that I had an extra set of gaskets so it wasn't a big problem for me. If I remember right, I only had to grind out around one opening. So you might get lucky and not have to do any grinding at all. Just check the fit first.

It might also be a good idea to get one thin walled socket the correct size for those nuts. I had sockets from three different sets but, only one of those sockets would actually fit in there.
 
(quoted from post at 10:23:25 08/15/20) Thank you all for the good information. I can always count on this crew!

New manifold is ordered. Fingers crossed that it fits reasonably well.

Funny story - I was at my local implement dealer (Rushford Minnesota) getting the gaskets - and I commented that perhaps it was time to think about one of those fancy Kubota or John Deere tractors. My new - old pal behind the counter laughed and said - no, that wont happen, I've see this condition all the time. You're pass the point of no return with an old tractor. You're a lifer at this point.

So here's to all you - us - lifers. Cheers!!
f yours isn't cracked or warped that area would seal up. Hopefully this link will help the next guy that comes along with a marginal manifold like yours. There web site is tricky to navigate at times but they should have one for the N 4 cylinder. There claim of reusing them worked for me twice. It is the same material you'll find on your catalytic converter and industrial machinery exhaust.

http://catalog.remflex.com/category_s/170.htm
 

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