dknarnd
Gold Member
WOW....Soundguy makes me want to buy one of these....that is the best post I have ever read on here.
Just bought an 8N
- Thread starter Mopar92
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Wow... what a great post. I am printing off your post! I should tell you a little more information about my 8N. It's already been converted to 12 volts. At idle around 550-600 rpms shows 25 lbs and at 1800 rpms is shows about 38-40 lbs of oil pressure. I did buy it from the place in Athens... haha.
I think they don't really like selling any tractor from there without an over run clutch. I think it's smart on their end just for safety. I do have a new over run clutch and I did buy a new buch hog from them also. It is a 5'. I will never be mowing high grass. It is smooth and level pasture. The brakes work excellent. I will tidy up a few lose wires and lines for sure. I am pretty **** about this type stuff. Guys, thanks for your input here, Keith
I think they don't really like selling any tractor from there without an over run clutch. I think it's smart on their end just for safety. I do have a new over run clutch and I did buy a new buch hog from them also. It is a 5'. I will never be mowing high grass. It is smooth and level pasture. The brakes work excellent. I will tidy up a few lose wires and lines for sure. I am pretty **** about this type stuff. Guys, thanks for your input here, Keith
Soundguy
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xlr82v2 said:
Are you aware that you can get positive ground builds.. and isolated ground builds out of those alternators... Not common.. but VERY possible..
Soundguy
xlr82v2
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Nope, never saw one of those disfigured Delco's...
And, why would you spend the money on something like that when the real thing can be had for about $25-30?? You don't have to change a single thing with the tractor to make it negative ground, so why would anyone bother with getting a positive ground Delco alternator?
And, why would you spend the money on something like that when the real thing can be had for about $25-30?? You don't have to change a single thing with the tractor to make it negative ground, so why would anyone bother with getting a positive ground Delco alternator?
Soundguy
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All depends. The fords with front mount distribuitors actually were designed to run positive ground, and it is how their ignition coil was setup. it is not a standard round can ignition coil, but a square one. Running it reverse polarity provided a slight change in spark. as you have a low ohm primary and a high ohm secondary and when you run it with the incorrect polarity you actually have a high ohm secondary in line with a low ohm primary.. like i said.. a real small difference.. but a difference none the less.
Also some small benefit gains with the lifespan of the ignition components based on the positive ground. Research 'edison effect' or 'thermionic emmision' for more details on why people might want to run a positive ground electrical system for a breaker contact ignition machine.
My answer was more or less to point out that the mere presence of an alternator on a machine does not 100% denote negative ground.. While it may be an assumption that is usually correct..it will not always be. ( I have heavy equipment / trucks parked in our workyard that have grounds other than negative, and are alternator based systems... If you are ever in a place that sells parts for big trucks.. especially cummins... see if they have an alternator application chart on their wall.. take a gander at it... you may be suprised that a significant minority portion of the chart is dedicated to isolated ground and positive ground systems.. )
Soundguy
Also some small benefit gains with the lifespan of the ignition components based on the positive ground. Research 'edison effect' or 'thermionic emmision' for more details on why people might want to run a positive ground electrical system for a breaker contact ignition machine.
My answer was more or less to point out that the mere presence of an alternator on a machine does not 100% denote negative ground.. While it may be an assumption that is usually correct..it will not always be. ( I have heavy equipment / trucks parked in our workyard that have grounds other than negative, and are alternator based systems... If you are ever in a place that sells parts for big trucks.. especially cummins... see if they have an alternator application chart on their wall.. take a gander at it... you may be suprised that a significant minority portion of the chart is dedicated to isolated ground and positive ground systems.. )
Soundguy
xlr82v2
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I don't think it makes any difference to the coil what polarity is used... the primary is still the primary and the secondary is still the secondary... however, it does make a small difference to the points, (probably some inductance/capacitance issues). At the spark plugs, the spark will reverse direction too... instead of going from center electrode to the ground electrode with the Pos Ground system, it will travel from Ground electrode to the Center electrode.
But, point taken... I retract my statement that said "MUST", and replace it with:
"99.998% of all 8N conversions with the 12V Delco alternator WILL be Negative ground, until Soundguy converts one with a Positive Ground alternator..."
But, point taken... I retract my statement that said "MUST", and replace it with:
"99.998% of all 8N conversions with the 12V Delco alternator WILL be Negative ground, until Soundguy converts one with a Positive Ground alternator..."
Soundguy
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xlr82v2 said:
Then you have OBVIOUSLY never seen the schematic of an ignition coil.
xlr82v2 said:
Thermionic emision / edison effect was already mentioned. Also.. keep inmind that electron current moves from negative to positive ( hole current / conventional current theory is what lists current moving from positive to negative.. CC is mainly to keep the big math a bit easier for the engineers.. however.. electrons jump neg to positive... etc.. )
Soundguy
Soundguy
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xlr82v2 said:
Perhaps it's a good thing you aren't an electrical engineer perfroming a critical job.
Study the schematic i am attaching of a kettering ignition system.
At issue is whether you are discharging thru the secondary only.. or if the primary will be inline witht he secondary.. it's an issue of a large resistance coil, or a large resistance coil plus a low restance coil. Not a huge issue.. but electrically speaking.. it is significant.
On later 8n, you can swap wires on the round can style ignition coil primary connections. On the early 8n, the coil is a squarish block atop the distribuitor and you cannot reverse the wireing connections on the primary.
Soundguy
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xlr82v2
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Soundguy, why are you trolling for an arguement?
No, I'm not an electrical engineer, and never pretended to be one...
But since you are (either one, the other, or both,) maybe you would like to educate all of us on "thermionic discharge/edison effect" and their/it's applicability to breaker ignition systems (although I fail to see why this is relevant to the OT of this thread).
So, to get back on track, in the real world, 99.98% of all Ford 8N 12 Volt conversions using the Delco alternator that you will ever encounter will be Negative Ground. Except, perhaps, for Soundguy's.
I didn't come looking for an arguement, and I'm not going to participate in one.
No, I'm not an electrical engineer, and never pretended to be one...
But since you are (either one, the other, or both,) maybe you would like to educate all of us on "thermionic discharge/edison effect" and their/it's applicability to breaker ignition systems (although I fail to see why this is relevant to the OT of this thread).
So, to get back on track, in the real world, 99.98% of all Ford 8N 12 Volt conversions using the Delco alternator that you will ever encounter will be Negative Ground. Except, perhaps, for Soundguy's.
I didn't come looking for an arguement, and I'm not going to participate in one.
xlr82v2
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OK, I had to go back and re-read this thread to see where it fell off the cliff...
When I said
I did not realize at the time that I would be jumped on by an EE with a chip on his shoulder and a point to prove... Yes, obviously, at the quantum physics level, there are certainly some differences. I'm not disputing that at all, one iota. All I'm saying is that it will still run, and run reliably for a long time. There are too many thousands of these frontmount tractors out there running everyday converted to 12V Negative systems with no problems to say otherwise.
However, since this particular tractor that we're talking about has the side mount distributor, and the automotive type coil, this whole thing is a MOOT POINT anyway, as it doesn't apply in this case unless the wires weren't swapped on the coil at the time the conversion was done.
So, to the Original Poster, as for myself, my apologies. I was in the garage with the toolbox, Soundguy, I think, was inside there with the electrons.
Soundguy's big post was excellent and had about all the info you need to run your 8N. Don't try to convert it back to Positive ground with the same alternator, or you'll fry the diodes inside.
Have fun with it, it was a great tractor in it's day. But, beware of it's limitations, of which there are several. There will be a learning curve if this is your first 8N... it definitely isn't a "modern" tractor. But, it will get it done, you just have to do a few things differently as compared to a more modern tractor.
When I said
I said that in the context of "real world, home mechanic, do it yourself, will it run or not after I convert to 12V Negative" frame of mind. The answer to that is, "Yes". See the quote above.
I did not realize at the time that I would be jumped on by an EE with a chip on his shoulder and a point to prove... Yes, obviously, at the quantum physics level, there are certainly some differences. I'm not disputing that at all, one iota. All I'm saying is that it will still run, and run reliably for a long time. There are too many thousands of these frontmount tractors out there running everyday converted to 12V Negative systems with no problems to say otherwise.
However, since this particular tractor that we're talking about has the side mount distributor, and the automotive type coil, this whole thing is a MOOT POINT anyway, as it doesn't apply in this case unless the wires weren't swapped on the coil at the time the conversion was done.
So, to the Original Poster, as for myself, my apologies. I was in the garage with the toolbox, Soundguy, I think, was inside there with the electrons.
Soundguy's big post was excellent and had about all the info you need to run your 8N. Don't try to convert it back to Positive ground with the same alternator, or you'll fry the diodes inside.
Have fun with it, it was a great tractor in it's day. But, beware of it's limitations, of which there are several. There will be a learning curve if this is your first 8N... it definitely isn't a "modern" tractor. But, it will get it done, you just have to do a few things differently as compared to a more modern tractor.
