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LATE FORD 8N SIDE DISTRIBUTOR

Late Ford 8N (50-52)

The "side mount" or "angle mount" tractor engine blocks should all have a timing hole on the right side near the back where the clutch/flywheel are located. It is covered by a teardrop shaped metal plate with one screw in the small end. It may be cleverly concealed under a thick layer of grease and dirt. The timing marks are stamped on the flywheel. There are no timing marks anywhere around the front of the engine (This is true for the TRACTOR engine. However, some of the engines found in tractors are not tractor engines. This same basic Ford engine was used in trucks, stationary applications like pumps, generators, and a bunch of other vehicles and equipment. It was a very popular and inexpensive design. Almost anything goes if you cannot read the serial number. Tractor serial numbers for 8N engines always started with the "8N" designation.

I might use a timing light to see how close my 1952 8N engine is to factory settings, but I prefer to set my final timing by trial and error the same way I dial in a front distributor engine that has no provision for a timing light. If the engine runs at all, mark where the distributor is, loosen the clamp, turn it about 1/8" and tighten the clamp. See if it starts and runs better. If so, try another 1/8" in the same direction. Likewise, if it gets worse, turn the distributor the other way. When you get close, try just 1/16" each way. You can fairly quickly dial in the sweet spot for your engine in this manner. Too much advance will start getting hard to start and will run hotter. Too much retarded and power will quickly drop off.

You probably don't have a temp gauge, but keep an eye on the exhaust manifold. It should come close to red, maybe a dull red with a good load on the engine for a few minutes. Glowing cherry red is too hot. Either too much advance, too lean on the fuel mixture, or both.

SIDE DISTRIBUTOR REBUILD

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This is what they look like off the tractor. Before you get this far, you should have turned the engine to Top Dead Center on the No.1 cylinder, and then lined up the timing mark on the flywheel with the pointer. Then mark No.1 plug wire on the cap. The cap is marked for No.1, but I've seen many distributors that were stuck in wrong and the wires moved to different holes. Save yourself some aggravation and find out now if that is the case. I'm going to thoroughly clean and service this distributor.

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Remove the cap and the first thing I see is a damaged dust cover. That big black hole right above my hand shouldn't be there. Put that on the list of parts I'm going to need. The rotor button looks brand new. I'll probably re-use that. Notice the insulator pass-through bushing on the right side in this photo. This one appears to be in good shape. I've seen cases where the bushing was gone, and the coil wire was connected directly to the points. That will certainly work, but unless this hole is sealed, the distributor can collect an incredible amount of dirt.

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The coil wire on this one was cut. That's a common practice for used parts. No problem, wasn't planning to use that anyway. Notice the gear drive on the end of the shaft. If it looks worn, plan on replacing that. There is a bushing a little further up the shaft. The gear and bushing are held in place with rivets. Both must be removed if you need to remove the shaft from the housing. This one is so dirty, I was planning to take it completely apart anyway.

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Pull off the rotor and dust cover to get at the points and condenser. I was not happy to see all the rust inside this one. Now is a good time to grab the top of the distributor shaft, set the points on a lobe (open), then attempt to move the shaft side-to side, while watching the point gap. Basically, any slop equals your margin-of-error when setting the points. This one definitely needs a new bushing. I've also spotted another problem. The pass-thru coil wire connects to the points with a flat piece of copper. This one is clearly broken.

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The top plate is easy to remove. Remove the points and condenser, then remove two screws and carefully pry the plate out. If it's rusty like this one, you may want to soak it in ATF or toss it in an electrolysis tank for a couple of hours. Once the top plate is out, it's time to go after those rivets on the drive gear and bushing. They are brass, so I simply peeled the head off with a sharp chisel and drove them out. You could use a center punch and drill bit to take the head off. Just left of the condenser in this photo is the broken piece of copper that should have been connecting the coil wire stud to the points. You could buy one for about $4, but I will make a new one from scrap copper sheet. You could also use a short piece of wire or pass the coil wire directly into the points. Whatever you do, make sure it only touches the points. If there is any electrical contact for this link between the coil and the points, the tractor will not start.

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Ok, rivets are out and here are all the parts arranged how they came off. This is an excellent photo to keep handy when it's time to put this back together. One photo can answer lots of questions. The advance weights on this one are in excellent shape, but that shaft looks bad. Hopefuly it will clean up ok, a new shaft assembly runs about $45. I'll try to clean and re-use this one. The bushing is pressed into the housing and accessible, once the shaft and advance mechanism is out. The easiest way to remove the old bushing is to run a tap in it, thread in a bolt, and then knock the bolt out from the bottom with a punch.

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These are the same parts after a thorough cleaning. The rusty parts spent about 4 hours in my electrolysis tank. That took care of the rust. If you want to know how electrolysis works go HERE. The distributor shaft cleaned up OK. It's not great, but this isn't an Indy race car either. I now have a complete list of replacement parts needed. I may decide to powder-coat the distributor housing if I can't shine it any better than this. There is a nameplate tag on one side of the housing. It's held on with a couple small rivets. This can be removed and replaced if you are going all-out with a restoration. Once I'm happy with the appearance, these parts will be set aside until I have everything needed to put it back together. That is why I take pictures. It might be a month before I come back to this project.

UPDATE - 3 Weeks Later

This is the new copper strip I cut from a piece of scrap copper.

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It's easier to drill holes in thin material like this if you sandwich the material between two pieces of wood. Drill the holes before you cut to the final shape and you won't have to do as much measuring to get them centered.

The following photo is the new dust cover held next to the original.

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There were two different dust covers listed on the web site. When the part didn't fit I went to see if I ordered the wrong one. Now the same site only lists one dust cover for all years. This one is wrong. The original fit down inside the distributor, so the tang on the distributor cap could engage the slot on the housing. This one will fit on the housing, but there is nothing to keep it from turning, and it jacks the cap out where the slot in the cap will only engage the slot in this dust cover. This means it would be relying only on the clamps to locate the cap, and it's going to take most of the tension off the spring terminal on the rotor. All I can do at this point is re-use the old dust cover or leave it out.

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Here is the completed distributor. The green insulator for the coil wire is a new one I made from a scrap plastic dowel that happened to be the correct diameter. The old one was cracked.

NEW DUST COVER

If you can't buy new plastic parts, make them yourself.

That dust cover with a hole in it was a problem. The distributor really isn't "done" with a broken dust cover in it. Trying to buy one that fits this distributor is currently impossible. One option is to MAKE one. The dust cover is plastic, and there are two-part plastics available that can be used to mold just about anything. I had never done it, so I didn't have a clue what was needed, or if the materials are safe to use at home.

So go to the web. Search for "Plastic Molding" and become an instant expert. Yes there are safe materials available (as long as you don't eat the stuff). There were even a few complete molding kits. After reading the reviews, it seemed as though the kits just packaged a bunch of things I didn't need, for more money than I wanted to spend. In hindsight, it might have been better to get a small starter kit (with "GASP" instructions), GRIN.

In order to mold a plastic part, First we need to make a mold. Ideally what we want is a perfect original of whatever part we want to make. Yea Right! We wouldn't be doing this if I had a perfect original! I own two side distributor tractors, and have one spare distributor. Started popping distributor caps, and all of my dust covers are in poor condition. All I could do is pick the best one to make my mold.

For the mold, something flexible seemed best. The dust cover is thin, so something that could be peeled back to release the part seemed like a good idea. Easy Mold Silicone Putty by Castin' Craft is a 2-part silicone material, that is worked like clay, or bread dough. The two parts are contrasting colors. Take equal parts of each, Fold and mash them together until the two colors become one even color. From that point we have a few minutes to press our part into the ball of goo to make a mold.

This stuff isn't horribly expensive, but there's no point in wasting it. The on-line instructions indicated building some kind of box for the mold. If the box is close to the size and shape of the part, it will take less material to make the mold. Hmmm, found some little round plastic bowls at the Dollar Store. They were the right shape, and slightly larger than the dust cover, perfect!

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Here's the first half of the mold. DON'T remove the original part until we make the second half of the mold!

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Here's the second half of the mold, made right on top of the bottom half, with the original part still inside. What you see in the photo is one of my new dust covers that didn't fit jammed into the top. You should be able to see the edges of both molds around the sides. The dust cover I jammed on top was just an attempt to use less of the silicone mold material, and provide a sturdy place to set something heavy. A couple of books or a block of wood should be enough to hold everything together, while the new plastic part cures. We don't want the two halves of the mold to float apart.

If the part we used to make the mold was perfect, the mold should be done. Mine was not perfect, so I took the mold apart, and trimmed where material squirted through cracks or holes. Trim carefully! One of those rotary Dremel tools might work better than a sharp knife for some things.

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For the plastic material to make the new part, look for a two-part 50:50 mix that will be relatively hard and heat-resistant. We don't want the new dust cover to get soft and sag down onto the points. Go to http://www.alumilite.com and browse their products. They will have something that will work. The material I used is an extremely tough Urethane, that is supposed to be good to 300 degrees. Hope it never gets that hot inside my distributor! Mixing equal parts is much easier than any other ratio. Sadly my new dust cover came out with a void missing n air bubble in the mold. The waste that squeezed out around the edge means I had plenty of plastic available, it just didn't get into every nook and cranny.

This was not my first attempt. The first batch of plastic set up while still being mixed! My mold could have been a little more sophisticated. Most molds will use some sort of fill channel and pour the plastic into the mold. I couldn't figure out how to do that. My mold has no fill channel so the top must come off to pour the material into the bottom mold. Then the tricky part is placing the top half of the mold without trapping bubbles.

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This is the same dust cover from the previous photo. It looked too good to give up. Why not try mixing a very small dab of plastic to fill in the gap? It worked! Here it is sitting between two abused originals, and looking like it might actually work. It's not perfect, imperfections were copied from the original that was used.

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Tried again a few days later and made a good one on the first try. Now that I have a working mold, I can make a new dust cover whenever I need one. I might even go crazy and add some black color pigment to the next batch.

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With a better original to work with, this would have turned out better. They fit perfectly with only minor cleanup around the edges.

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