Ford 860 spark plugs

ken in wisconsin · Aug 31, 2018

I have a 1957 860 and recently installed a Pertronix electronic ignition. I want to install new plugs and wonder what I should use. I am looking at a post from 2001 wherein JHunt recommended 437 plugs and not 216 plugs. It seems that the 437 extends further into the combustion space and thus do not foul. I don't even know what make these numbers are for and hope someone can help. Also, I read somewhere that with the electronic ignition the plug gap can be increased for better performance. Any truth to that, and if so, what should the gap be?

old · Aug 31, 2018

I just installed a set of NGK3112 plugs in my 841S today. I switched to them because they seem to hold up better then the champ or auto lite plus do. Gap should be 0.025

old-9 · Aug 31, 2018

The 437 number is for Autolite. They seem to hold up better than Champion plugs.

jeffcat · Aug 31, 2018

I love NGK plugs. Go on Ebay and look your plugs up. FAR cheaper than an auto store. Most of the time they don't even have them in stock.

Hayfarmer · Aug 31, 2018

I use the 437 in my JD430 and they seem to work well. I have electronic ignition and I open up the gap a a little. I don't know if it helps performance but doesn't seem to foul plugs as much in an older engine.

Steve@Advance · Aug 31, 2018

The Pertronix ignition is simply a point eliminator. Though it will give a more consistent spark, it is not a higher intensity spark, so the gap will remain the same.

If your engine is consuming oil and tends to foul the plugs, you can go to a hotter heat range plug. If it's working days are over, a hotter plug will be better for idling, short runs, low power applications.

Be sure the thermostat is in and working, and that the carb is adjusted properly, and the air cleaner is properly serviced.

deanostoybox · Sep 1, 2018

Pertronix says if you use their "40000V" coil you can open spark plug gap to 0.035".

My 51 8N has electronic ignition, but it is not Pertronix.
AL216 plugs that were on the tractor when we got it.
Cap, rotor, and wires that were on tractor when we got it.
No idea how old they were, looked like candidates for replacement then

N.O.S. Blue Streak points FD8081XV gapped 0.025
Condenser is removed.
Generic 3Ω coil from something (?) I junked out years ago.
GM HEI ignition module NAPA PN TP45 mounted on an old computer power supply heat sink.
Points switch module through a signal inverter consisting of a 2N2222 transistor and a 4.7kΩ 1/2Watt resistor. The most current the points see is ~3mA and that load is resistive, not inductive, so there is never any arcing at the points. The points will fail mechanically long before they fail electrically.

I run the plugs gapped at 0.040". Tractor seems to like it. As to improved power and or economy, I had run the tractor around 150 hours before the conversion, and have run it about 550 hours since. I cannot say that I see any noticeable change. YMMV.

Ford 860 spark plugs

ken in wisconsin

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old

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old-9

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jeffcat

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Hayfarmer

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Steve@Advance

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deanostoybox

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