We went to a car show Saturday and I took my coil tester along to display in the back of the truck. I had a fellow come over to me and said I should try adjusting my coils to 0.97 amps. They would run a lot better. Now, I hesitate to believe this, but I have to wonder why he says this? I wonder if he is using a buzz box and by experimenting around he found 0.97 to run better because it got rid of some double sparks he didn't know he had? Anybody got any idea where he may have come up with that number? Sure is a long way from 1.3 amps. I don't think I'm going to bother trying it, but I am curious what his reasoning is.

I can't tell what his reasoning is. There are a lot of myths out there.

Steven

Hal, I wouldn't bother either. With the coils set at 1.2-1.3 amps the coils will fire just fine with 2.5 volts or less. Thats a virtually dead magnito output. If the upper point is set to drop when the points are opened the coil will not double spark no matter what the current is set too.

Hal:

The earlier Heinze coils were set at a similar lower amperage...... maybe he doesn't know the difference with the standard Ford coils ??

The TT I gave my brother last year started very easy on mag. The coils were only pulling .9 amps. I set them to 1.2 on my hcct and even though it ran the same you had to be a bit quicker when starting it on mag.

Of course all of this means nothing anymore as he had a T expert proclaim that starting it like I showed him would result in a broken wrist. So, they pulled out the floorboards and connected the fishing boat battery directly to the mag post. Proud of themselves that they got the coils to buzz and the truck started right up.

It no longer runs on mag but that has nothing to do with coil adjustment. Somebody tell me again why we give stuff to little brothers? Mine could ruin an anvil with a leather mallet.

Gary,

Fortunately, you should be able to recharge the magnets in the car. Then, never let anyone connect DC to the mag post or mag contact on the coil box.

There are several threads on doing the in-car recharge.

Its way past an in car recharge (I did that about 9 years ago when I first got it off of ebay for $455). I believe he melted the solder out of it as it now reads open. I have a re-wound field coil but the truck is 650 miles from here. I should have just sold it for a couple of grand and been done with it.

A few of the forum posters that are familiar with the truck can attest that it used to start easily on mag as well as run on mag (never had a battery). Ken Swan, Keith Barrier, and Ray Elkins are all pretty familiar with the "possum wagon".

What the your stranger at the car show was probably thinking is with regards to the 1926-27 T. See the improved Ford coil box was moved to the engnie so the spark plug wires are shorter, almot 75% shorter with regards to spark plug #1. When you use the formula for Ohms law for a standard model T spark plug wire, the difference in wire length accounts for about a difference of .33 amps deleverd to the spark plug. As everyone knows the increase of amps is inversly perportional to volts so the spark plug is actually getting less juice and therby a weaker spark, a slower burn, and a noticable loss of power. Ford know this and original coil setting specs were different for each coil depending on spark plug wire length. For the improved Ford the spark plug wires are all he same length so the coil setting was simply reduced to .97A, however, battery manufacturers at the time were actually supplying 7V batteries which of course are not available today. so to get the same performance with a 6V battery the original 1.2A-1.4A coil setting still is best. This of course is based on an other wise stock engine with ZDP in the oil. Once you consider the magnetic field changes when using aluminum pistons or head, the change to the magnetic flux density adversly affects pole strength which in turn as everyone knows will affect the flame propagation during a predetnation cycle to reduce the power output an additional amount porportional to the square of the brake horspower. This problem can be offset by driving with one headlihght on bright and the other on dim, or reducing tire pressure by 3 PSI on the left front wheel while traveling in an easterly direction or reverse for a westerly direction. Since most people's driving habits require driving in both directions it is best to reduce the pressure in both front tires by 3 PSI for baloon tires or 12 psi for clincher, unless using a tire flap in which case all bets are off.

And that's why Model T's have counter-rotating front wheels

Be_Zero_Be

Jeff,I just mentioned to friends the differance in bright and dim headlights on our T involves water! Bud.

Jeff,
Is that a roundabout way of saying that the coil setting advice came directly from Seth?

Eric,
No.

Nice Eric. You and the Coilman are two peas in a pod. Why don't you call me a jackass and tell me to buzz off like he does? I'm sure that you would get away with it.

Relax, I meant it in good fun.

Why not just add jojoba bean oil to the rear axle? I heard it does the same thing.

The only possible reason that lower current setting will make the car seem to run better is when running the coil box off of a 6V battery. One peculiar thing about T coils is that if you have them adjusted perfectly - they don't run very well on 6V because it takes about 4 mSec to get them to ramp up to the firing current level and that much time is a noticeable timing lag at the higher RPMS. Now if you reduce the current level at which they fire - you will in fact speed them up at 6V noticeably and that may be what the guy is doing but the downside is less spark energy. When someone says their T runs just great on 6V battery and no problem even at high speeds - you can bet they have their coils set to substantially less than 1.3 amp average. The setting of 1.3 is in fact an average current setting on an HCCT or Strobo-Spark while the actual peak current at which they fire is much higher. Ron Patterson article explains that all very well.

Yeah Gary, I hated to see the possum wagon leave this neck of the woods. It got more attention than anything at the relay for life show. C-YA, KB