1947 Ford 8N

Rayman66

Member
Friends of mine have a 1947 Ford 8N that was converted from 6 volt positive ground to 12 volt. One of my questions is, is this still positive ground or is it now negative ground? The distributor plate shows what appears to be a "burn" area and we can't get any spark at the points nor at the spark plugs. Last one; is there an easier way to remove the hood short of acetylene cutting torch?
Any and all help will be greatly appreciated.
Thank you
 
"The distributor plate shows what appears to be a "burn" area"

What do you mean by the "distributor plate"?
Whether it's a '47 2n or a '48 8N really doesn't matter.
Both would have a front mounted distributor with the coil on top.

If that's the setup you have, why do you want to remove the hood?
The whole distributor comes off with two bolts and three clips.
You set the point gap and timing on the bench then bolt it back in.
The distributor only goes on one way without breaking it.

To answer your question though, the hood comes off with two
bolts at the bottom of the doglegs and four around the dash.
The fuel line has to be disconnected and the gas tank comes
off with the hood. Much lighter if not full of fuel.
 
"is there an easier way to remove the hood short of acetylene cutting torch?"

Good grief - get the manuals. No need to remove the hood to change the points in the distributor. Dist come off with two bolts and can only go back on one way!
 
The Ford 8N Tractor Model was first released off the Highland Park, MI production line in July, 1947. Model '8N' defined as year, 1948, for that would be the new model year, and "N" was designation for 'tractor'. Look on the starter pocket for a date code boss. It will have the casting code date of when the engine block was cast. For example, 'I167' with code breakdown defined as such: First character a letter of the alphabet, denotes month, with letter 'A' beginning with January. The second and/or third characters will be numerals defined to be the day of the month; and finally a single digit to denote year cast. In my case example, it breaks down to September 16, 1947. That is simply the day your engine block was cast, not the day your tractor was built. You can get an estimate on the day of build by adding 30 days to the casting code. That's then an approximate day your tractor was build but not definitive...a few other variables come into play.

Original N-Series electrical system was/is 6-volt positive ground. Many 12-volt conversions will still use the original 6 volt starter and keep positive ground but the efficient way is to go negative ground with an alternator.

Tim *PloughNman* Daley(MI)
 
Have an additional question but first Thank you to all who replied. We have been checking and have power to the "coil" but when we pull a spark plug and ground the plug there is no spark. Now what???
 
The problem is in the distributor.

I'm on my phone and can't post a link so scroll down to page 8 and see my reply to stryped on 10/17. That will tell you what to look for in the distributor.
75 Tips
 
(quoted from post at 17:03:05 11/06/16) How do I get to page 8? And Thank you for replying.
b:482f608779][i:482f608779]
Rayman66,
Here is what Bruce, wants you to find and read. Tells you what you need to know!!!!!!!!!!!!!

Copied from page8....:


6 volt or 12 volt?
Front or side distributor?

There are two schools of thought when it comes to getting a non-running tractor to start. One way is to just start replacing every part you can get to until it starts or you run out of money. The other way is to take a step-by-step approach to solving the problem, working from most likely to least likely. The trick to fixing these tractors (or trouble shooting any piece of equipment) is to be systematic about it. You need to isolate the problem step by step and work from most likely to least likely.

After all those parts bought & time & money invested, you still do not know if you have a spark or fuel problem.

" it fires for a split second because the starter disengages but never takes off."

That tells me that you have a spark problem.

Put your battery on a charger. (see tip # 60)

You need a strong battery to:

1. Close the solenoid

2. Spin the starter

3. Engage the bendix

4. Provide voltage to the coil.

As the battery gets weaker, the first thing to fail is your spark. If the battery is almost totally dead, all you will hear is the solenoid clicking.

In addition to charging the battery, chances are you need new cables as well (tip # 41). And, don't forget to clean all the grounds, to include the mating area between the starter & the block.

The more current you use to spin the starter, the less you have for the ignition.

While you are waiting for the battery to charge, check for fuel. Get a can & put it under the carb. Remove the bolt in the bottom of the carb; as long as the fuel is turned on, you should see gas flowing out of the carb. It should fill a pint jar in less than 2 minutes. If it’s a dribble, or runs for 5 seconds & stops, or none at all, you have solved half the problem: it’s fuel related. If gas flows well out of the carb & only stops when you turn it off at the sediment bowl, chances are very good it’s not a fuel problem. If it does not have gas coming out of the carb at a steady stream w/ the bolt out for at least 30 seconds, you have a fuel problem. First, remove the gas cap. Your vent could be clogged & it vacuum locked. If that doesn’t work, tap the carb bowl w/ a hammer handle in case the float is sticking closed. (don’t whack it w/ the head of the hammer; you can crack the bowl). If you still don’t see gas flowing, the N has three fuel screens; one in the brass elbow, one in the top of the sediment bowl & one on the stem of the sediment bowl in the gas tank. (see tip # 45) Check the screen in the elbow (see tip # 56) & the screen in the top of the sediment bowl. (don’t worry about the one in the tank) Both probably need to be cleaned. If you have the fuel knob turned on all the way, & 1 gallon or less in the tank, it may be trying to feed off of the reserve inlet which is probably clogged. Only open it 2 full turns. Put at least 2 gallons in the tank. (and do not forget to turn the gas off; see tip # 9)

After the battery is charged, hook up your spark checker*, turn the key on & crank the engine. If the spark jumps the 1/4” gap, you probably don’t have a spark problem. If it won’t jump the ¼” gap, you have a spark problem. If the ammeter needle shows a constant discharge, or doesn’t move at all, that also tells you that you have a spark problem. Jump the ignition switch w/ your jumper wire & see what happens. If it runs, you found the problem. If it doesn’t have spark after you jump the ignition switch, post back for more info on further troubleshooting. (and do not forget to turn the ignition switch off; see tip # 38 )

There are ways to check for spark & fuel that work & ways that don't. For example, having gas to the carb is nice, but having it past the float is what counts! That’s why removing the 7/16” bolt in the bottom of the carb is the way to check for fuel. And, same thing w/ spark at the plugs. Some folks think that checking for spark means pulling a plug wire off & looking for one. Well, it's the distance the spark jumps at the plug that gives you the info you want. It takes about 17kv to jump a 3/16" gap & 22kv to jump ¼” in the open air. Remember, it’s 14psi outside of the engine & about 90psi at a 6:1 compression ratio in the cylinders & compressed air creates electrical resistance, so you really need the 17-22kv to fire the plugs when the engine is running. A store bought plug checker (in the picture) will work better than an old plug because it won’t shock the snot out of you like an old plug might!

Post back with results or more questions.[/i:482f608779][/b:482f608779]
 
[b:aaf513e9d6][i:aaf513e9d6]AND.....:
Here is the info. from Bruce on the distrib.......:

Copied from page 8......:

Time to pull the distributor.

Assuming that the bushings & advance weights are ok (*see below), & that you have correct voltage to the coil (battery voltage with the points open and about half that with the points closed), the problem is in the distributor.

Once you get the distributor on the bench, the first thing you need to check is bushing wear. If the shaft has any sideways movement AT ALL, the bushings must be replaced. (*** see below).

The most common electrical failure (no spark, weak spark) points on the front mount are:
1. The insulator under the brass concave head screw & where the copper strip attaches. (it’s fiber & will wear out; poke & prod w/ your meter leads to make sure it still works) If you need to replace the insulator, use a .250 x 3/8 nylon square nylon anchor nut available at most big box home stores
2. The pigtail at the bottom of the coil not making contact w/ the concave head brass screw inside the distributor. (With the coil on, the pigtail must firmly contact the brass screw. No contact = no spark
3. The copper strip is broken or grounded to the plate. (look very carefully for cracks & breaks).
4. The condenser wire grounding to the plate or side of the distributor.
5. The tab on the bottom of the coil not making contact w/ the brass button on the cap. (With the cap on, the tab must firmly contact the brass button. No contact = no spark.)
6. Incorrect positioning of the spring clip on the plate causing the pigtail to ground. (the open part of the clip goes between 7 & 9 o’clock on the plate. That puts the straight part of the clip opposite of the timing screw at 3 o’clock)
7. Incorrect seating of the coil on the distributor due to a loose bail or no gasket.(the coil must not move at all; if it does, replace the gasket or bail. Or stick some cardboard under the bail).
8. Water/moisture inside the cap due to gasket failure or the absence of a gasket. (the cap AND coil have gaskets)
9. Dirty/corroded/burned/incorrectly gapped or misaligned points. I use only Wells, Blue Streak or Echlin brand points (* *see below). If you are using quality points and cannot get the gap to open to .015, chances are you need to replace the bushings.
10. Burned rotor, cracked/carbon tracked cap.
After you find the problem & re-check the point gap, do a continuity check before you put the distributor back on the tractor. Before you start, make sure your meter/light works.

With the distributor still off the tractor, follow these steps:

1. Coil off, cap off, points open. One probe on the brass screw & the other on both sides of the open points. On the side closest to the cam, you should have continuity. Not on the other side! If you do, you will also have continuity everywhere because the points are grounded.

2. Coil off, cap off, points open. One probe on the brass screw & the other anywhere on the body of the distributor. You should have no continuity! Now, rotate the tang on the distributor....as the points open & close, you have continuity (closed) and lose it when they open.

3. Put the coil on the distributor, cap off, points open. One probe on the lead on the top of the coil, the other on the cam side of the open points. You should have continuity!

4. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other anywhere on the body of the distributor. You should have no continuity!

At this point, I just put the distributor, coil & cap all back on the tractor as a unit. The reason I do this is because it is real easy to get the cap or coil misaligned trying to put it back together, one piece at a time. The result is something gets broken or you get a ‘no spark’ problem.

It's possible to put it back on wrong & break it. Look at the slot on the end of the cam shaft. Whatever angle it happens to be, turn the distributor tang to match it. Make sure you can tell the wide side from the narrow side on both the cam & distributor! (close counts). Place the distributor on the front of the engine, gently push it in place & slowly turn the distributor body until you feel the tang slip into the slot. Rotate the distributor body until the bolt holes line up. Hand tighten the two bolts until the distributor body is flush with the timing gear cover.

* Unscrew the plate hold down screw & remove the C clip to get the plate out. Remove the shaft & weights. The weights should freely move.

* *NAPA part numbers:
• Points: FD-6769X
• Condenser: FD-71
• Rotor: FD-104
• Cap: FD-126

*** There are three ways to replace the bushings in a front distributor:
1. Buy new bushings (part numbers 9N12120 front & 18-12132 rear). Press out the old ones, press in the new ones and ream to fit. CAUTION: do not try this unless you have a press & know how to use it. If you break the base, a new one costs $130. If you bend the tower which holds the front bushing, a new plate will cost you $30.
2. Take the new bushings and distributor to your local machine shop.
3. Send the distributor out for bushing replacement if you do not have a local machine shop.

75 Tips[/i:aaf513e9d6][/b:aaf513e9d6][i:aaf513e9d6][/i:aaf513e9d6]
 
(quoted from post at 12:00:12 11/07/16) Another question: Serial number is 8N 122654 can someone tell me what year for sure this is.
Thank you!
b:df60bb86b4][i:df60bb86b4]
According to the ser# listing you give,....8N 122654, would be a 'Mid-yr' 1948 8N.

GB

[/i:df60bb86b4][/b:df60bb86b4]
 

"Another question: Serial number is 8N 122654 can someone tell me what year for sure this is.
Thank you!"

that serial number is 1948.

to determine ground, look at the two battery cables. the ground will go directly to the body or frame. see what that post is identified as on the battery, and that's which ground is in use.
 
(quoted from post at 15:29:10 11/06/16) Have an additional question but first Thank you to all who replied. We have been checking and have power to the "coil" but when we pull a spark plug and ground the plug there is no spark. Now what???

The first thing I would chech is to see if you have current flowing through the inline resister.
 
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