spark plugs for an H

Rat in Can · Apr 25, 2014

I got a master tune up kit from tractor supply for the h and it came with autolite plugs 3116 and on here in the past everyone said auto lite 386 or 388 so are the 3116 any good or are they too cold for the tractor it doesn't get worked much an hr or so a week just too plow snow or to go for a drive too keep the oil moving. any thoughts would be appreciated.

John T · Apr 25, 2014

The 3116 is close to the heat range of 386 or slightly hotter 388, HOWEVER unlike the 386 or 388, its a NON Resistor Plug which is better to use if it happens to be a Magneto Ignition. A Battery powered coil distribution is more forgiving if resistor or non resistor plugs are used. The 3116 should do just fine, I wouldn't run out and buy 386 or 388.

You get plenty of opinions on spark plug brands lol so Im ONLY talking about heat range and resistor versus non resistor NOT BRANDS. Ive had good luck with Autolite myself, others maybe prefer AC or Champion TO EACH THEIR OWN..

John T

Rat in Can · Apr 25, 2014

it had champion d16 in it when I changed them.

FBH44 · Apr 25, 2014

Some time ago I got a 2014 Autolite Spark Plug catalog mailed to me. The Heat Range Chart on page 4-5 lists these plugs in descending order of hotness.

18MM thread size
1/2” reach
7/8” hex
HOT rating
 388 Standard resistor plug
 3116 ‘Power-Tip’ Non-Resistor plug
 386 Standard resistor plug
 -- gap --
 -- gap --
 373 Standard Non-Resistor plug
COLD rating

Each step up = 70º – 120º increase in spark plug tip temperature.

Self-cleaning zone = 500°C to 850°C tip temperature.

TOO HOT = Possible severe engine damage, pre-ignition, detonation with racing / high performance engines. .
TOO COLD = Possible fouling, possible mis-firing, but no engine damage.

rustred · Apr 25, 2014

D 16 is the factory plug that most of these different models came with from factory. you can go to the next higher heat range with no problem.
back then the tractors earned their keep in the field with long hrs. with D16 plugs. now these old tractors are a hobby thing and need a hotter plug for all the cold starts and stops and hardly even get to operating temp. very bad for an engine. they have to be put to work hard every so often.

David G · Apr 25, 2014

You are fine.

rustyfarmall · Apr 26, 2014

(quoted from post at 11:25:49 04/25/14) I got a master tune up kit from tractor supply for the h and it came with autolite plugs 3116 and on here in the past everyone said auto lite 386 or 388 so are the 3116 any good or are they too cold for the tractor it doesn't get worked much an hr or so a week just too plow snow or to go for a drive too keep the oil moving. any thoughts would be appreciated.

I've got 3116s in 2 of my Hs. It IS the plug of choice.

pete 23 · Apr 26, 2014

The 3116 is a warmer plug than the 386 or 388 and if chart is correct is a projected tip plug and spans a Champion D-15 Y and D-18Y which are both projected tip plugs. The projected tip is what IH switched to back in the 706 days to provide a broader range, cleaner burning plug. All the new IH tractors came from factory with a 8-comm when I worked there until they switched to the D-15 Y as factory. Parts stores substituted the D-16 as being the same as 8-com but I have a letter from champion that says they are very similar but not exactly same as the 8-com was provided to mfg's only.

spark plugs for an H

Rat in Can

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Rat in Can

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