Model A spark plugs

[JJASON]

I drive my 29 pickup around town,lots of stop lites.What number on spark plug would be good for me to use?

[Mitch//pa]

Use the 3x plugs if your not cheep

[Kurt in NJ]

I have used the same 3X plugs for the last 35 years, from long parades at idle to all day at 65 they have worked better than any other plug i have tried

[700rpm]

3X. About $20 ea. at O'Reilly's. Sometimes they have to order them for you.

[C26Pinelake]

The 3X plugs are very good and I use them in my cars. Having said that, the much cheaper plugs sold by all the vendors are also very acceptable. If you are not interested in show buy the cheaper ones. Wayne

[willobs]

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3x Best

[Mitch//pa]

Here are two for a little cheaper. And free shipping
http://www.amazon.com/Champion-Plug-...hampion+3x+429

[Ron in Quincy]

I like the 3X plugs as they are a hotter plug and set deep in the cylinder head; I believe the 4 cylinder A engine preforms better with a hotter plug and the 3X does not seem to foul like the Auto Lite that many use.

Ron

[Tom Endy]

I have been running the same set of 3X plugs for the past 20 years. I take them apart occasionally and clean and re-gap them. We had a lady in our club who has an original 31 coupe she has owned for over 50 years. She asked a fellow club member who was the club's technical at the time to give her car a tune up, which she paid him to do. Some time later she discovered he had discarded the 3X plugs and installed a set of plugs from off the shelf. She was furious and asked me if I would get her a set of 3X plugs and install them for her, which I did.

I think 3X is the way to go.

Tom Endy

[1930marie]

I just went through this awhile back. The 3x - 16 worked fine, but not perfect like the 3x-18 recommended here on FB. A club member was kind enough to flow test my jets and show me his flow testing set-up. Since, I have made up a lot of various size jets and found the exact combination that works for my current engine condition. I went on a 10 mile run this morning, car fired on first tap of the starter and all is well. Love the #18 plugs - I ordered mine through Napa and the had them in two days. It took alot of effort, however, the end result was well worth it. ps making a sized jet takes less than five minutes. Have fun with your "A!"

[Mitch//pa]

Originally Posted by Tom Endy

I have been running the same set of 3X plugs for the past 20 years. I take them apart occasionally and clean and re-gap them. We had a lady in our club who has an original 31 coupe she has owned for over 50 years. She asked a fellow club member who was the club's technical at the time to give her car a tune up, which she paid him to do. Some time later she discovered he had discarded the 3X plugs and installed a set of plugs from off the shelf. She was furious and asked me if I would get her a set of 3X plugs and install them for her, which I did.

I think 3X is the way to go.

Tom Endy

I wonder if they were OE style?

[Bob C]

Originally Posted by 1930marie

I just went through this awhile back. The 3x - 16 worked fine, but not perfect like the 3x-18 recommended here on FB. A club member was kind enough to flow test my jets and show me his flow testing set-up. Since, I have made up a lot of various size jets and found the exact combination that works for my current engine condition. I went on a 10 mile run this morning, car fired on first tap of the starter and all is well. Love the #18 plugs - I ordered mine through Napa and the had them in two days. It took alot of effort, however, the end result was well worth it. ps making a sized jet takes less than five minutes. Have fun with your "A!"

What is an 3x-16 and 3x-18? Are you talking about Champion W16 and W18?

Bob

[J Wade]

What is the difference between the 3X-18 and 3X-16 plugs?

[henry's 31]

There is no question the Champion 3X are great. I run Champion W18 (518) for a fraction of the cost and they seem to do well. You can get them or order them at any Auto Parts Store.

[Bruce,Upstate NY]

My favorite for many years is C 16 C Champion. I don't know if they are still available.
(Running 5.5 comp and Simmons )

[BILL WILLIAMSON]

There are NO MIRACLE spark plugs, if you've found a brand & a heat range that runs GOOD & burns CLEAN, just forget them & enjoy the TRIPS & replace them with the same kind, every 15,000 or so miles.
Vermin has BRAND NEW Champion C-16-C's, If they're good enough for a PACKARD, they're good enough for a Model A named VERMIN!
Bill W.

[Mike V. Florida]

Model A spark plug heat ranges
Champion W18 = close to original 3X
Depending on your driving habits, etc., a cooler plug may be the one for you:
Champion W-14 (cooler than W-18)
Champion W-10 (cooler than W-14)
Motorcraft TT-10 (same as W-14)
Autolite 3076 (same as W-14 and TT-10)
Also Champion W16Y which some people will argue that it's cooler than Champion W-18 but hotter than W-14 as the numbers would suggest. On the other hand, for years and listed as such on their official heat range chart, the engineers at Champion proclaimed that the Y means projected nose (which it is, you can tell by looking at it) and for this reason it is supposed to run hotter at slower speeds.
Conduct a proper heat range test as follows to see what is needed for your car and how you drive:
Drive around for at least 30 minutes to allow engine heat to build and then drive out someplace where you can run the car at a sustained speed on a straight road for a few miles without having to slow down or stop, very important.
Run the car up to the maximum speed in high gear that you would typically drive if you decided to drive fast and I don't mean dangerously high speed.
Hold the car at that sustained speed and without letting off the throttle, reach over and turn off the ignition. Let off the throttle, push in the clutch quickly and coast over to the side of the road. Open the hood and allow the engine to cool off a bit (allow to cool off completely if running an aluminum head).
Remove the spark plugs and examine the color and condition of the electrodes and insulators. The color will be a true indication of how hot or cold the plugs are running. But remember ... during the test if you let the engine slow down or let it idle and then check the plugs you will have changed the effects and not get a true indication. I've seen many a person let an engine idle, check the plugs and then claim they were just right only to discover later that the plug heat range was too hot.
It they are white, the plug is too hot. Go to a colder plug.
If they are black, they are too cold. Go to a hotter plug.
If they are a shade of tan, they are just about right.
Also understand that all this is not set in stone. A person who putts around at say, 35 or 40 MPH and never faster may need a hotter plug. The lower the combustion chamber temperature the hotter the plug should be. On the other hand, as conditions cause the combustion chamber temperature to rise, a colder plug may be necessary. You just don't want the plugs to be sooty black and foul out which means they're too cold or chalky white which means they're too hot. You want the plugs to be somewhere in between like light brown to grayish tan. However, slightly white may not be too bad unless it is "chalky white."
Keep in mind that the plug descriptions are for engines in good condition, correct carb mixture, good hot ignition, etc., etc.. One with bad rings for example can cause oil to get on a correct heat range plug and foul it out (short to ground down the side of the center electrode) where it won't fire. It will be black and oily.
On the other hand, a plug that is running too hot will turn chalky white or bright white. This can reduce the life of the plug or even cause the electrode to burn up. A plug can also get hot enough to glow which can ignite the mixture before the spark occurs (pre-ignition). This can be bad news... During pre-ignition the temperature inside the combustion chambers can reach WELDING temperatures in just a few seconds. The result is a hole can melt right in the middle of an aluminum piston! ... and to make matters worse it can be completely silent .. you won't hear it until it's too late .. no detonation sounds, knocks or pings.
The condition just described is for a plug with the wrong heat range (too hot) run in an engine in good condition, correct carb etc.. the same as described above. If it is known that the correct heat range plug was used then other causes such as too lean a fuel mixture, timing advanced too far, etc., etc., are overheating the plug.
This is where "reading the plugs" can be used to determine all sorts of engine problems. But as mentioned it must be known that the correct plug was used to start with.
The heat range test is used to make this determination. At the outset always choose a colder plug first if you are not familiar with the nature of the plugs said to be hotter. That way the worst thing that can happen is the plug can foul out whereas too hot a plug can cause the problems above.

This information is from Larry Brumfield the creator of the Brumfield High compression head.

[Mike V. Florida]

Heat range test. Different driving conditions, fuel additives, etc can change how a specific spark plug works in the engine,

Conduct a heat range test as follows:
Drive around for at least 30 minutes to allow engine heat to build and then drive out someplace where you can run the car at a sustained speed on a straight road for a good distance of say a mile or two without having to slow down or stop, very important.

Run the car up to the maximum speed in high gear that you would typically drive if you decided to drive fast and I don't mean dangerously high speed.
Hold the car at that sustained speed and without letting off the throttle, reach over and turn off the ignition. Let off the throttle, push in the clutch quickly and coast over to the side of the road.

Open the hood and allow the engine to cool off a bit. Remove the spark plugs and examine the color and condition of the electrodes and insulators. The color will be a true indication of how hot or cold the plugs are running. But remember ... during the test if you let the engine slow down or let it idle and then check the plugs you will have changed the effects and not get a true indication. I've seen many a person let an engine idle, check the plugs and then claim they were just right only to discover later that the plug heat range was too hot.

It they are white, the plug is too hot. Go to a colder plug.
If they are black, they are too cold. Go to a hotter plug.
If they are a shade of tan, they are just about right.

Also understand that all this is not set in stone. A person who putts around at say 35 or 40 MPH and never faster may need a hotter plug. The lower the combustion chamber temperature the hotter the plug should be. On the other hand, as conditions cause the combustion chamber temperature to rise, a colder plug may be necessary. You just don't want the plugs to be sooty black and foul out which means they're too cold or chalky white which means they're too hot. You want the plugs to be somewhere in between like light brown to grayish tan. However, slightly white may not be too bad unless it is "chalky white."

Keep in mind that the plug descriptions are for engines in good condition, correct carb mixture, good hot ignition, etc., etc.. One with bad rings for example can cause oil to get on a correct heat range plug and foul it out (short to ground down the side of the center electrode) where it won't fire. It will be black and oily.

On the other hand, a plug that is running too hot will turn chalky white or bright white. This can reduce the life of the plug or even cause the electrode to burn up.

A plug can also get hot enough to glow which can ignite the mixture before the spark occurs (pre-ignition). This can be bad news... During pre-ignition the temperature inside the combustion chambers can reach WELDING temperatures in just a few seconds. The result is a hole can melt right in the middle of an aluminum piston! ... and to make matters worse it can be completely silent .. you won't hear it until it's too late .. no detonation sounds, knocks or pings.

The condition just described is for a plug with the wrong heat range (too hot) run in an engine in good condition, correct carb etc.. the same as described above. If it is known that the correct heat range plug was used then other causes such as too lean a fuel mixture, timing advanced too far, etc., etc., are overheating the plug.

This is where "reading the plugs" can be used to determine all sorts of engine problems. But as mentioned it must be known that the correct plug was used to start with.

The heat range test is used to make this determination. At the outset always choose a colder plug first if you are not familiar with the nature of the plugs said to be hotter. That way the worst thing that can happen is the plug can foul out whereas too hot a plug can cause the problems above.

This information is from Larry Brumfield the creator of the Brumfield High compression head.

[BILL WILLIAMSON]

For any heat range to be proper, you MUST torque them to 25 Ft Lbs, or just enough to CRUSH a new plug washer. A loose plug will run HOTTER, as most of the heat is dissipated through the threads & the washer.
Bill W.

[Gary Karr]

I run original 3X plugs on all of my Model As. They are easy to clean and re-gap. I have never had problems with them.