HEI in 283?

[RichardJ]

Do the Math?

What Math? Ohm's law does not apply for an Inductor. Close, but no cigar.
Ohm's law says, V = R x I . Voltage = Resistance x Current.

Resistance measured in Ohms and Current represented by the letter I is measured in Amps.

The 1st image below is similar, BUT an Inductor represented by the letter L is measured in Henries and the current is represented by delta I divided by delta t.
That means change in current divided by change in time. Time is a very important part of every part of a ignition event and is measured in Milliseconds.

I used the image below to show the formula for current through an Inductor, because ASCII Symbols are a pain.

This is how Henries are measured.
One Henry is also equal to: Joule/Ampere2, Ohm-Second, and Weber/Ampere.

Right, what ever that means.

People use an Ohm meter on a inductor (Coil), because they can't measure Henries. It is useful to identify one coil from another, but beyond that it is worthless.

Insert a analog Ammeter in the circuit between the GM HEI and the wire you are using to power it and you will get a reading of about 2 Amps.

2 Amps


""Voltage Leads Current through an Inductor ""

Simply put. When you apply a voltage to a coil, the magnetic field that is building, opposes the flow of current through the wire. By the time current reaches its maximum, less than 3 milliseconds, dwell has ended, the plug fires and then it starts all over again.

Everybody likes GM HEI's, GM used 14 gauge wire for the HEI. Why all this silliness about a 12 or 10 gauge wire.


The Hot when running circuits in the fuse box are powered by a Pink 12 gauge wire from the ignition switch.
When running, that P12 wire is carrying the current for the radio, wiper motor, heater fan, dash lights, fuel gauge and what ever else I forgot.
Adding the HEI load to the fuse box is just adding more load to the Pink 12 than it was already carrying.

IF THE 12 PINK IS BIG ENOUGH TO SUPPLY THE FUSE BOX PLUS THE HEI, WHY DO YOU NEED 12 GAUGE TO SUPPLY THE HEI BY ITSELF?

Using a 10 gauge for a HEI is interesting. You've heard of a weakest link? A 10 gauge wire for HEI is the opposite. The entire truck will burn to the ground before that 10 gauge would suffer any damage what so ever.

The Pink 12 actually splits off before the fusebox and goes to the bulkhead connector, where it supplies power to the ballast resistor for the stock ignition.