Fun with Front Mount Distributors

[mwbailey]

Some of my issues may have been answered in the response to Tom888fish by Bruce, but I might have two questions left:
1. IF I replace the distributor (1949 8N front mount, 12V conversion that has been running), should I go with rebuilt, new, John Smith, .. . ? Looks like $160 at shops like nnalert, $120-130 on eBay or Amazon, "pending" (for 6V, not 12V) at John Smith.
2. Should I try something else before getting the distributor:

My mistake, left the key on and the battery ran down to stone dead. Tried to recharge, but neither of my rechargers wanted to indicate it had reached full charge. Battery check at Advance Auto said amps was good, voltage a little low at 12.39V. Cranked fine but would not start.

Figured I might have burned the points with the key left on -- seems like I saw that somewhere -- so I got new tune-up kit at TSC (#1238070). New points would not open no matter how I positioned the adjustment screw -- just rotates 360 degrees, right? Got mad and went to NAPA for another set of points (Echline CS35). They open only about 6-8 thou no matter how I positioned the adjustment screw. Haven't even gotten to putting in the new plugs after I gapped them.

Since I broke the "cannot replace distributor out of sync with camshaft tab" on the old distributor shaft, I replaced the distributor shaft with a new one. Tractor has run several months just fine since then (so I'm guessing the distributor cam is not worn out already).

OK, broken tab, left key on, dead battery. . . maybe I should try another hobby, but the gravel drive needs scraping and I enjoy running the ole 8N. AND, I've learned to remove the front mount distributor without much problem!

 

[Bruce (VA)]

First off, buy shirts & chicken feed at TSC. Never tractor parts.

Next, don't buy parts off of eBay either.

Their are three well known & trusted used parts dealers that many of us use; John Smith is one of them & nnalert's is the other.

The Echlin points are fine, just pricey.

I can talk you through rebuilding your distributor as can many other folks around here. But, you will need a bit more than average ability & access to a press.

If you don't have the time or inclination to do that, get a rebuilt one from John or nnalert's. Both will be fine.
75 Tips

 

[Colin King]

If I'm understanding you correctly, you cannot set the points gap to .015?

Have you adjusted the advance screw on the side of the distributor?

Another idea would be to check the condition of the bushings both at the base of distributor housing where the tang come out and in the distributor breaker plate. Take out the cam and weight assembly to check the bushings.

Excessive wear on the bushings will make it hard to impossible to set the gap correctly.

If the bushings are worn, rather than purchasing a new or used distributor, send yours out for rebuilding. I can give you a recomendation if that is what you would like to do.

Colin, mn

 

[old]

Key left on points burned out and good chance coil is also bad now. As said buying things like points at TSC is well from the land of almost NEVER right so junk form the get go. If you can not gap the point to the 0.015 needed then you may have bad distributor bushings or the wrong points or some thing other odd wrong

 

[greywolf224]

You got some great advice here which I cannot come close to giving but I have a question.

Before leaving the key on, did you have points or timing issues?

I don't see how leaving the key on could affect the distributor housing or bushings thus giving you timing issues. I can see you burning up points but....?

I am thinking that maybe just maybe when you disassembled the distributor something got misaligned.

 

[mwbailey]

Yep, greywolf, I agree -- good advice. Since nnalert is just across the state line from me (and I've done business with them a few times in the past), I'll probably plan a short road trip soon!

The tractor was running fine before I left the key on (to run the gas out after turning off at the carburetor bowl), so I figured that the distributor should be in good shape. I replaced the "main" bushing when I replaced the distributor shaft with the broken tab. There was actually little -- as in, NO -- slop in the fit; I had gotten the bushing at nnalert when I got the distributor shaft. I vaguely recall getting the bushing that's "inside" the distributor (attached to the plate), too, but those parts looked more fragile and I didn't have any play, anyway. That is to say, I didn't replace the second bushing.

I'm not sure I understand quite how you could burn up points or a coil by running electricity through them -- OK, so the coil doesn't have as much time to cool as it might when the points open on occasion. But, I've learned on this Forum and elsewhere that real live data is a lot better than "theory"!!

You guys are good; I appreciate you pointing me in the right direction.

 

[Royse]

"so the coil doesn't have as much time to cool as it might when the points open on occasion."

The points open more than just "on occasion". Four times per rotation.
Leaving them closed gives you a 100% duty cycle. Big difference.

I don't see how the bushings would have went bad from that either.
Cheap points maybe, or the wrong points. NAPA points should be fine.
How are you trying to adjust them? Are you using the straight
edge and drill bit method in the I&T manual or do you have a jig?

One other thought, I have heard of the cam block coming
loose from the shaft on an aftermarket distributor shaft.
Does yours turn on the shaft?

 

[mwbailey]

Yep, cam is turning. I was using the tabs at the camshaft (bottom) end of the distributor shaft to turn while looking for points opening and closing. Even thought my eyes might be playing tricks on me, so turned the shaft while holding onto the cam to FEEL the lobes -- they were there and moving!

Don't have jig, so would have to use drill and straight edge. However, I was assuming points would be gapped the same no matter what the timing -- within reason. So, until I could get the points gapped, I figured I didn't have to worry about timing. I did notice, in the operator's manual, that Ford listed a tool to ADJUST the breaker points for parallelism (paragraph 364.c.4). Don't know how you'd do that without bending something!

I was being a bit facetious about the points opening "occasionally". I think I saw somewhere that Dell suggested points would be closed about 55-60 degrees of each 90 degrees of rotation. So, it looks like the points would be open about 1/3 of the time; and that would occur four times per rotation as you mention. That's a pretty significant amount. And, I think he said that you couldn't measure dwell on a front mount distributor (I guess you might be able to check it somehow off the tractor, but I'm not going to worry about that).

 

[Dell (WA)]

mwbailey.......lets talk about "dwell". Dwell meters read "across" the primary windings of yer coil. On the weird 4-nipple front mount, ya gotts the TOP terminal which is one side of the primary winding. Now HOW do you gitt to the OTHER side of yer ignition coil primary terminal? Its HIDDEN under the square can coil. Iff'n yer sphincterly challenged, you can "file" a small slot between the coil and cap joint. So yeah, you can measure the "DWELL", but then what??? Ya gotta take the cap OFF so you can adjust the points (0.015") and then puttchur cap back on, turn the ignition ON and crank the engine so you can measure the dwell again. Me? I think it would be eazer to remove the whole dizzy and adjust the points on the kitchen table. Its just 2-bolts and you re-snapple the capple.

The ONLY thing you can eazily do on the weird 4-nipple front mount is to "POLISH" the INVISIBLE corrosion from between the points. Me? I'd clamp the corner of a $1-bill between the points and pull. Simple, eh? .......Dell, yer self-appointed sparkie-meister

 

[mwbailey]

[b:cf0103f2f2]Dell[/b:cf0103f2f2], I always enjoy your responses -- to my problems or to others. I don't intend to worry too much about dwell, and it's not the first time.

In 1976, I bought a brand new F-100, six cylinder, standard shift, long-bed pickup -- had to pay extra to get a rear bumper. I also paid extra to get the FOUR repair manuals for that year, expecting to do all the work on it, myself. After an appropriate number of miles (maybe 1000), I figured it was time for a minor tune-up. I took my timing light and multi-functional tach-dwell-etc.-etc. meter out to the F-100 along with the maintenance manuals. As I opened the hood and the manuals, I found that they had started putting solid state components in those trucks. I adjusted the timing and went back inside! No dwell to worry about. . . . Many years later, I did manage to use the manuals when I replaced the engine; still no dwell.

Fortunately, I have a 1967 Olds 442 that I can use my multi-functional meter on. But the meter hasn't come close to the 8N.

 

[Colin King]

I like your philosophy on TSC. Big box store quality and service rarely impresses. At both my locally owned Napa and farm hardware store I'm greeted by first name and they usually know why I'm there before I tell em.

Colin

 

[mwbailey]

Got to nnalert's today -- even took The Wife! Went whole hog and got a rebuilt distributor AND 12V coil; then stopped by the Flying Pig for BBQ.

Installed the distributor with coil plus spark plugs from the TSC tune-up kit. Started fine and ran as well as it has (or better) over the almost one year I've had it.

Thanks again for support.

 

[Royse]

Glad to hear you got it running again.
What are you going to do with the old distributor?

 

[Den N Ms]

mwbailey,Great it's good to hear your running again.Now would be a good time to go to TSC,Autozone,ect and buy a cheap red clearance light to mount on the dash and have it come on when your ignition switch is on.So you can tell if you left it on, even from a distance.

 

[mwbailey]

The Wife actually suggested that I get the 12V coil while we were at Just 8Ns -- I would then have a spare, if I could get it tested. She thinks I like to collect parts and don't throw anything away. Maybe she's right; I don't have a square inch in the workshop to do any work since it's filled with junk, I mean, spare parts!

Don't worry [b:ae0763f3d4]Den M Ns[/b:ae0763f3d4], The Wife also had input on not leaving the key turned on. I brought it to her and put it in her cute little hands!

 

[greywolf224]

Glad you got her going.
Was the original distributor an original or aftermarket housing?

Are you going to try to see what's wrong with the original distributor? That would eat me away not knowing why I could not gap the points correctly?

 

[mwbailey]

Hmm, thought I had replied to [b:8d3a4036c4]Royse[/b:8d3a4036c4], but it must have gotten caught in the ether somewhere. I'll try to recall. It was something like: The Wife actually suggested that I get the new 12V coil and then I could use the old one as a spare if it checked out OK. She thinks I can't throw anything away. Don't know why she would say that. After all, the workshop seems to be filled with junk, I mean, spare parts.

[b:8d3a4036c4]Ben M Ns[/b:8d3a4036c4], The Wife also solved my problem of leaving the key turned on. I delivered the key to her cute little hands after I finished this afternoon!

My guess, [b:8d3a4036c4]greywolf[/b:8d3a4036c4], is that the other distributor was an original. I'm with you, I don't like to be buffaloed, so I'll probably check it out thoroughly. The new/rebuilt one was the most expeditious way to get the 8N running again. After seeing the instructions in the owner's manual to "adjust" the points if they were not parallel, I might see what bending the "fixed side" of the points would do -- I do have both the TSC and the NAPA set to work with. It's all still sitting out on the bench for further investigation. At least I'm pleased that it's running without having to buy a battery. I just KNEW it would end up with something as simple as that. But the battery is only a couple of years old, so I didn't jump on that first (well, other than having Advance Auto check it).

 

[rrucker]

now that's a great idea!