8n Advance weights...

[LtfJ]

I re-bushed this front-mount distributor and installed a new advance assy, and now can't get the static timing right. Took it apart again and noticed the slanted guide slots on the bottom of the weight assembly are canted in the opposite direction from the original. My poor old brain can't figure out if this would affect the static timing. Anybody seen this before? [I uploaded a picture into the 'Blog/Post Gallery', but don't know what to do next to make it visible]

 

[JMOR]

Maybe you can e-mail me your picture & if you wish, I can post it. All the Ford 8N distributors that I have seen, both front & side mount have been made such that the slots are angled so that the inside (next to shaft) leads the outside when turned in normal direction of rotation.

 

[JMOR]

(quoted from post at 19:46:42 03/23/11)
Maybe you can e-mail me your picture & if you wish, I can post it. All the Ford 8N distributors that I have seen, both front & side mount have been made such that the slots are angled so that the inside (next to shaft) leads the outside when turned in normal direction of rotation.

ure enough different.

 

[LtfJ]

Thank you for the offer to upload the picture for me. I've attached a copy [phone camera... shaky hands... not proud of the quality].

This is Dad's 8n. He's had it for 50 years, and I've worked on it since I was a kid. I thought I knew a lot about it, but I don't understand why I can't get the static timing set. I appreciate any help.

Thanks again. LtfJ

 

[lha]

Those two are certainly different in that the slots angle in opposite directions.Whether the new one will work would depend which way the weights turn when they move outward.Looks to me the new one is designed for opposite orientation.---lha

 

[JMOR]

(quoted from post at 22:41:04 03/23/11) Thank you for the offer to upload the picture for me. I've attached a copy [phone camera... shaky hands... not proud of the quality].

This is Dad's 8n. He's had it for 50 years, and I've worked on it since I was a kid. I thought I knew a lot about it, but I don't understand why I can't get the static timing set. I appreciate any help.

Thanks again. LtfJ

As I said earlier, every 8N I have ever seen, front or side, has slots as in your old unit. Not to conclusively say that they can't be made to work the other way, but...
Unless the maker of the part took into account the position of the inner end of the slot, then the static timing would be different since the drive tangs would not keep same alignment with breaker cam flats. This could have been compensated for by a slight rotational difference in drive tang assembly to slotted plate before brazing or crimping the two parts together.
It could also be a case of some 3rd world 10 cent an hour 'assembler' simply installing that slotted plate upside down. Where did you buy that part?
Prestolite made a distributor where the slots were straight (perpendicular to shaft) with no slant, so anything is possible.

With a couple of straight edges and some way to measure angles (protractor) you can compare the relationship between the drive tangs & the flats on the breaker cam & determine whether the two units differ or not. If different, I say you found your problem.
I would be in contact with place where I bought it.

 

[don b1]

Jesse.....this is the correct answer.
It could also be a case of some 3rd world 10 cent an hour 'assembler' simply installing that slotted plate upside down. don b

 

[Hobo,NC]

I have a brand new'n sit'n in front of me just like it,,, when I get caught up with take it apart...

The advance function works as it should but unsure if it affects base timing

 

[LtfJ]

I bought it from Yesterday's Tractor, who has told me that they've never had a problem with that part but that I can return it if I want to. Well...

More confusing yet is the fact that every picture I've seen from other suppliers seems to show the same orientation as the replacement; namely, opposite of the original. ??

When I move the weights manually, the cam rotates CCW [advance], which I think is correct. I could accept that the slots will work with either slant (although I suspect the advance curve would be different), but the fact remains that I can't get the static timing set right, and I just can't see that being caused by anything other than this assembly. Am I missing something, or should I start begging YT to exchange it?

 

[JMOR]

(quoted from post at 14:40:29 03/24/11) I bought it from Yesterday's Tractor, who has told me that they've never had a problem with that part but that I can return it if I want to. Well...

More confusing yet is the fact that every picture I've seen from other suppliers seems to show the same orientation as the replacement; namely, opposite of the original. ??

When I move the weights manually, the cam rotates CCW [advance], which I think is correct. I could accept that the slots will work with either slant (although I suspect the advance curve would be different), but the fact remains that I can't get the static timing set right, and I just can't see that being caused by anything other than this assembly. Am I missing something, or should I start begging YT to exchange it?

ike dob-b & Hobo said, that is about what we get these days from the chi-coms & others over there. Hobo said advance seems to work & I believe it could (maybe not same as Ford's did, but advance) & I believe you about the static advance. Unless they attached the drive tang portion to the plate, taking into consideration the inside end of slot position at rest, then that is a problem. How many degrees off are you? You aren't at zero centrifugal advance much of the time beyond startup on a working tractor, so if it doesn't interfere with starting, it may not be a problem?? Your old one doesn't look too bad in the photo....maybe use some of old & some of new?

 

[Dunk]

It would appear that the plate was stamped on bottom side up.

 

[Hobo,NC]

(quoted from post at 23:23:59 03/23/11) I re-bushed this front-mount distributor and installed a new advance assy, and now can't get the static timing right. Took it apart again and noticed the slanted guide slots on the bottom of the weight assembly are canted in the opposite direction from the original. My poor old brain can't figure out if this would affect the static timing. Anybody seen this before? [I uploaded a picture into the 'Blog/Post Gallery', but don't know what to do next to make it visible]

Plate is indexed and crimped on,,, I can see were flip'n it would get ya a +1/8"..
I wanna press it off and re-crimp when I find the time...

Theirs more than one way to shin a cat,,, this one came out of a YT mag'ers but can not remember who...

http://i102.photobucket.com/albums/m103/hobo1301/frontmtadvance004.jpg[IMG]

[img]https://i102.photobucket.com/albums/m103/hobo1301/frontmtadvance005.jpg

[/img][/url]

I would contact Don b1 and B done with it...

 

[LtfJ]

>>"Like dob-b & Hobo said, that is about what we get these days from the chi-coms & others over there."<<
Yup. Hurting the country, IMO.

>>"Unless they attached the drive tang portion to the plate, taking into consideration the inside end of slot position at rest, then that is a problem."<<
You must be right, since I think the same thing. a-hem.

>>"so if it doesn't interfere with starting, it may not be a problem??"<<
It does, indeed, interfere with starting.

>>"....maybe use some of old & some of new?"<<
That's perfect! Why didn't I think of that??? I'll do that and post the results. Thanks!

 

[Hobo,NC]

&gt;&gt;"so if it doesn't interfere with starting, it may not be a problem??"&lt;&lt;
It does, indeed, interfere with starting.

HOW :?:

 

[LtfJ]

Thanks for the pictures. I didn't realize they were indexed with a 'flat' like that.

Are ALL of the replacements built with the slotted plate upside down (meaning 'wrong')? Am I the only one who can't make it work?

Thanks again. You forum guys have been a great help!

 

[Hobo,NC]

Wiggle the circle clip off (be careful it has wings) and take a look... Static Bullchit timing does not mean much to me,,, I usually set the timing with the engine run'n... Static timing base timing,,, its just a starting point good enuff for a back yard bob... I have never been able to over advance a front mount... Total is what i am look'n at,,, were it idles at I could care less long as it does not crank over hard...

 

[LtfJ]

>> >> >>"so if it doesn't interfere with starting, it may not be a problem??"<< << <<

>> >>"It does, indeed, interfere with starting."<< <<

>>"HOW :?:"<<

It won't start. It fires, sometimes to the point that I think it's about to start, but it won't run. Spark is there, and SEEMS strong enough. Voltage at the coil is 'okay' (battery voltage with points open; ~2V with points closed... the same since I replaced the ballast resistor with a home-made one 5 or 6 years ago), and I've tried priming it with ether without result, so I'm pretty sure it's not a fuel problem.
I bought a replacement ballast resistor (just in case I'm wrong about the spark) and a carb kit (just in case I'm wrong about the fuel).

BTW, you suggested that I
"contact Don b1 and B done with it... ".
mmm... ahhh, 'Don b1'; is... is he, like, a... hit man?

 

[36 Coupe]

Put a timing mark on the pulley.A timing light will tell you if the spark is advancing.

 

[Hobo,NC]

(quoted from post at 05:01:54 03/25/11) &gt;&gt; &gt;&gt; &gt;&gt;"so if it doesn't interfere with starting, it may not be a problem??"&lt;&lt; &lt;&lt; &lt;&lt;

&gt;&gt; &gt;&gt;"It does, indeed, interfere with starting."&lt;&lt; &lt;&lt;

&gt;&gt;"HOW :?:"&lt;&lt;

It won't start. It fires, sometimes to the point that I think it's about to start, but it won't run. Spark is there, and SEEMS strong enough. Voltage at the coil is 'okay' (battery voltage with points open; ~2V with points closed... the same since I replaced the ballast resistor with a home-made one 5 or 6 years ago), and I've tried priming it with ether without result, so I'm pretty sure it's not a fuel problem.
I bought a replacement ballast resistor (just in case I'm wrong about the spark) and a carb kit (just in case I'm wrong about the fuel).

BTW, you suggested that I
"contact Don b1 and B done with it... ".
mmm... ahhh, 'Don b1'; is... is he, like, a... hit man?

He is the man,, 1-888-355-9937

Advance it all the way are 1/8" what ever rocks yer boat,, you can do-dat while its on the tractor :wink:

$10 for a std. ign. spark checker and take the guess work out of it....

[/img]

 

[JMOR]

(quoted from post at 07:22:54 03/25/11)

(quoted from post at 05:01:54 03/25/11) &gt;&gt; &gt;&gt; &gt;&gt;"so if it doesn't interfere with starting, it may not be a problem??"&lt;&lt; &lt;&lt; &lt;&lt;

&gt;&gt; &gt;&gt;"It does, indeed, interfere with starting."&lt;&lt; &lt;&lt;

&gt;&gt;"HOW :?:"&lt;&lt;

It won't start. It fires, sometimes to the point that I think it's about to start, but it won't run. Spark is there, and SEEMS strong enough. Voltage at the coil is 'okay' (battery voltage with points open; ~2V with points closed... the same since I replaced the ballast resistor with a home-made one 5 or 6 years ago), and I've tried priming it with ether without result, so I'm pretty sure it's not a fuel problem.
I bought a replacement ballast resistor (just in case I'm wrong about the spark) and a carb kit (just in case I'm wrong about the fuel).

BTW, you suggested that I
"contact Don b1 and B done with it... ".
mmm... ahhh, 'Don b1'; is... is he, like, a... hit man?

He is the man,, 1-888-355-9937

Advance it all the way are 1/8" what ever rocks yer boat,, you can do-dat while its on the tractor :wink:

$10 for a std. ign. spark checker and take the guess work out of it....

[/img]

are in mind that while I don't have one of the "wrong-way" slotted advance mechanisms in hand, I can &amp; did determine (by both measurement &amp; calculation, which agreed within one degree...yeah, I was surprised too) how wrong the static advance would be 'off' IF the slots are reversed AND no compensation of plate relative to drive tangs is made..better sit down! 26 distributor degrees which is 52 degrees at crankshaft! If this is the way it is made, then it ain't gonna start up. :!: LATER: Upon comparing HOBO's picture (new) of the indexing 'flat' on the shaft/plate assy to my old one, it appears that they made an attempt to compensate for the opposite slant of the slots by positioning the plate CCW relative to the shaft.........so, if they got the amount of compensation correct, then maybe it will start up &amp; run.

 

[LtfJ]

JMOR, your suggestion to use some of the old + some of the new was a good one; unfortunately the new weights won't fit onto the old shaft. I may try turning down the old shaft to fit, but I'm losing confidence that the timing problem is actually in the advance assembly.

I clamped the drive tangs of both old and new shafts into the vise so they would be in line (with a towel under for visibility):
The new guide plate is indeed rotated CCW (by about 6 degrees). I guess that means the manufacturer intended to compensate for the different slots, although the 6 degrees isn't enough in MY distributor.

I was convinced the problem was due to a defective advance assembly, but I can't actually find any problems with it. If it's NOT the adv assy, what the heck is it? And how do I fix it? I started to file out the adjustment slot in the distributor body so I could rotate the breaker plate enough to get the base timing set, then realized that moving the plate that far would cause alignment trouble with the coil 'pigtail' thingie. I'm as lost as ever.

Thanks again for all the input.

 

[JMOR]

This has gone long enough now that I'm not sure what the original problem was that prompted you to replace advance assy???? Maybe you never stated it?

"I was convinced the problem was due to a defective advance assembly, but I can't actually find any problems with it."

 

[LtfJ]

I tried to start the 8n in sub-freezing temps. Starter broke. Fixed that. Now it cranked good and tried to fire, but wouldn't start. It was getting fuel, spark, and compression, but still wouldn't run, so I figured it had to be timing. When I pulled the distributor, the leaf springs were broken off the advance weights and they were flopping around on worn bushings (plus the shaft bushings weren't great), so I figured if I replaced all of that I'd be home free.
That's pretty much the story. I know that static timing ['steel rule against the tangs on the wide side... 1/4" from the edge of the hole'...etc.] is just a 'starting point', but if you can't get that set right, something is wrong. What would you do next?
Again, thanks to everyone for the input.

 

[JMOR]

(quoted from post at 03:13:37 03/28/11) I tried to start the 8n in sub-freezing temps. Starter broke. Fixed that. Now it cranked good and tried to fire, but wouldn't start. It was getting fuel, spark, and compression, but still wouldn't run, so I figured it had to be timing. When I pulled the distributor, the leaf springs were broken off the advance weights and they were flopping around on worn bushings (plus the shaft bushings weren't great), so I figured if I replaced all of that I'd be home free.
That's pretty much the story. I know that static timing ['steel rule against the tangs on the wide side... 1/4" from the edge of the hole'...etc.] is just a 'starting point', but if you can't get that set right, something is wrong. What would you do next?
Again, thanks to everyone for the input.

I would make the tractor run with the old parts first, then introduce new parts.

P.S. The "overall" measurement to make in comparing the old and new ought to be the angle between two straight edges, one on drive tangs &amp; one on the point cam flat (pick the one of 4 that yields smallest angle then make all measurements on that one). By doing this you include the advance mechanism, the shaft, shaft to slotted plate, slots, point cam, the whole 9 yards. If they are different, you will know by how much. My old unit is 26 degrees, here, @ no advance.

 

[LtfJ]

Nothing about this makes sense, and I don't have any more ideas, so I cheated. I widened the adjustment slot as much as I could without moving the coil contact out of reach (A homemade jumper with a bare lug on that end insure the coil's spring thingie will connect).

The points still didn't open during the static timing procedure, so I widened the gap til they did. Wound up at 0.018"; hopefully close enough.

 

[JMOR]

(quoted from post at 17:18:10 03/29/11) Nothing about this makes sense, and I don't have any more ideas, so I cheated. I widened the adjustment slot as much as I could without moving the coil contact out of reach (A homemade jumper with a bare lug on that end insure the coil's spring thingie will connect).

The points still didn't open during the static timing procedure, so I widened the gap til they did. Wound up at 0.018"; hopefully close enough.

It will run!