using up ignition points on 8N

Billrog

Veteran Member
Joined
Dec 9, 2014
Messages
1,720
Location
Armstrong, British Columbia
Tractor
Kioti CK27, 580 SuperM Case Backhoe
I knew a fella that hooked up his battery backwards and was burning out points until some one pointed it out to him? At least that's what he told me.
 

Soundguy

Old Timer
Joined
Mar 11, 2002
Messages
52,238
Location
Central florida
Tractor
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
I knew a fella that hooked up his battery backwards and was burning out points until some one pointed it out to him? At least that's what he told me.

that's pretty much 100% BS too. There's some other part of the story thay are not telling you.

apparrently there is some huge lack of understanding of basic electronic concepts AND how a kettering ignition system ACTUALLY works.

at the root, you have a battery, a coil with a primary and a secondary, and breaker points, and a condensor.

power from bat thru coil and closed breakers . IE.. primary current flow. mag field charges, breakers open, mag field collapses, induces a voltage on the secondary which is the high voltage discharge. Breakers are still opening and close enough to arc, so the condensor acts as a switch debouncer for a few moments untill the point gap widens. rinse and repeat.

too small a points gap and they never open enough and will arc and burn.

open condensor and the points will arc and burn

shorted condensor and the points will never actually open, as the condensor is across the contacts, and that just leaves you with current flowing in the primary circuit... leading to eventual thermal damage of the coil, dead battery, and non running engine.

oil/grease ont he breaker contacts will cause arcing and burning

too much primary current ( 6v coil in a 12v system ) will lead to reduced points life due to thermal damage and excessive metal transfer and pitting of the breaker contacts.

too little primary current ( 12v coil in a 6 v system, or a 12v coil in a 12v system PLUS some ballast resistor added in because the users doesn't know electronics ) yeilds no spark, or very weak spark.

Lastly, ultimate voltage of the spark at time of arc is defined by the size of the arc gap, and the physical characteristics of the atmosphere of the cylinder in which it is firing. In other words.. if doesn't matter whether you buy a stock coil or one of the fancy ones that claims 80,000v... the spark will still jump at say.. 9000v, if the arc gap and physical atmospher of the cyl allow it to do so... thus using stock plugs and gaps, you NEVER see the inflated claims made by some components.

It pays to actually know a little bit about this stuff.

As for the backwards battery / reversed polarity. it makes a LITTLE difference. the biggest difference can be measured ONLY with an electron microscope, and a very expensive, very sensitive piece of industrial grade equipment.

The issues? metal transfer direction of the breaker contacts. SOME contacts are set for a polarity, and have different coatings on each of the breaker contacts. .. Mostly these days, they are ALL the same, both sides.. so this part makes little difference. ( you might have seen this in some mechanical voltage regulators that ware also marked with a polarity preference ).

secondly, you can get a big resistance vs a big resistance plus a little resistance issue on the coil if ran at incorrect polarity.

take a typical 6v coil that needs no ballast resistor. primary impedance ( kinds like dc resistance ) can be around 1.5-1.8 ohms. the secondary may be 4000-8000 ohms.

If you have a polarity mismatch on some coils, you may be seeing a 4000+1.5 vs 4000.. IE.. not much difference. some applications this is difficult to correct.. like the ford 9n/2n/early 8n front mount coil.

Notcie the voltage and impedance relationships. your target primary current is usually somewhere around 4 amps a little more or a little less, depending... usually less.

when you see a ford front mount coil/tractor that is 6v, it also uses a ballast resistor. but when you see a ford 6v coil / side mount.. it does not use a ballast resistor.. why? coil impedance. the front mount is not a 1.5-1.8 ohm coil. it is a .9-1.2 ohm coil.. thus it needs a ballast resistor inline with it to maintain a correct primary impedance and thus primary current. without it, primary current would be 5-6 amps or more. the side mount coil already has the 1.5-1.8 primary it needs due to the way the coil was designed.. the correct number of turns of the correct sized wire. Move up to the 12v fords in the 65+ range... they used a resistor wire, and a 6v coil, and a bypass relay. Relay put full voltage to the coil when starting, because full voltage won't be 12v when starting due to increased starter demand from the larger engines, and the still anemic battery technology of the day., once started, the resistor was no longer bypassed, and thus you have a 6v coil, plus resistor, running on 12v. primary impedance and primary current were both happy.

That's the basics of the why and how of it.
 

RalphVa

Super Member
Joined
Dec 19, 2003
Messages
6,939
Location
Charlottesville, VA, USA
Tractor
JD 2025R, previously Gravely 5650 & JD 4010 & JD 1025R
I'd think you can still get an electronic ignition replacement for points. I had an Alfa Romeo that ate points. Got a kit way back then that was just a sensor that bolted the same place as the point mechanism did. The sensor could read the high points on the came lobe to tell when to fire. Of course, you could rotate the distributor to get the right advance, etc. Don't recall what it was but I'll bet you can get a system on line.

My Alfa always would sit there idling very smoothly after going mile after mile. Before, after 1,000 or so miles, it would idle roughly and would cut out when revved, and you really needed to rev that 1,300 cc engine.

Ralph
 

Soundguy

Old Timer
Joined
Mar 11, 2002
Messages
52,238
Location
Central florida
Tractor
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
I'd think you can still get an electronic ignition replacement for points. I had an Alfa Romeo that ate points. Got a kit way back then that was just a sensor that bolted the same place as the point mechanism did. The sensor could read the high points on the came lobe to tell when to fire. Of course, you could rotate the distributor to get the right advance, etc. Don't recall what it was but I'll bet you can get a system on line.

My Alfa always would sit there idling very smoothly after going mile after mile. Before, after 1,000 or so miles, it would idle roughly and would cut out when revved, and you really needed to rev that 1,300 cc engine.

Ralph

Pertronix ( and a couple others ) make EI kits. there is a magnetic ring that you slide down on the dizzy shaft, and then a hall effect sensor kit.

If your alfa ate points, it was because of one of the reasons I mentioned above, or some mechanical issue like non square striking points., etc.
 

tcartwri

Elite Member
Joined
Mar 28, 2010
Messages
2,609
Location
Ontario
Tractor
CT235
Sorry, your answer is 100% incorrect, and is bad info.

Ic14sb coil run with no resistor on 12v.

Go back to school...

There are no starter bypass relay on N!!

Please don't offer advice if you have 0 knowledge of the application! :(

You know what's hilarious. I can't find specs in this magical coil because a Google search only pulls up your eight million posts on the same subject.

You're as big of an *** in all of those as well. Thumbs up!
 

Soundguy

Old Timer
Joined
Mar 11, 2002
Messages
52,238
Location
Central florida
Tractor
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
Gee, that's weird, I just did a Bing search on:

Ic14sb ign coil

1st hit was Napa, and it showed price, volts, and a specification page ( that had not much more than volts and mounting )

2nd hit was a reseller, also listed voltage.

As for pertronix kits? I don't care for ei, I have no trouble maintaining points.

I do have a kit on a farmall c, just because it was free.

It starts just as good as my points tractors. No way I'd pay 70+$ for a kit when good points cost 10$ and can last decades and don't die If you put the battery in backwards.

As for your opinion of me, what can I say? I'd rather be a smarta** than a dumba**.
So.. Lets do the tally real quick.. Hmm.. Looks like my info was correct... Soo.. I guess since I got the smarta** position.. Looks like you are stuck with the other one? Darn.. Tough luck.. Good luck next time! :)
 

lilranch2001

Super Member
Joined
Nov 25, 2009
Messages
7,085
Tractor
na
I am responding only so I can continue to see the discussion......
:D
 

Soundguy

Old Timer
Joined
Mar 11, 2002
Messages
52,238
Location
Central florida
Tractor
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
wp_ss_20160216_0001.pngFor the " show me " people, here is a good pic of the coil from eBay.

Clearly states no resistor required.

Also, for those that haven't figured it out, ic 14 costs more, the 'sb' line is the economy line.. No yellow paint...
 
 
Top