This month we pick up our discussion by examining how to upgrade a points distributor to an HEI system. demands for better emissions and fuel economy in the mid s necessitated leaner fuel mixtures. These leaner mixtures required greater voltage and more spark to ignite.
This challenge led GM engineers to design the HEI distributor, which effectively replaced the points-style systems that had been in service for decades. The GM HEI distributor incorporated a magnetic pick-up assembly that contained a permanent magnet, a pole piece with internal teeth, and a pick-up coil.
This device senses pulses emanating from the distributor as it rotates, then provides a low-voltage digital on-off signal to the ignition module, where it is interpreted as an rpm signal. The ignition module uses this information to determine when to fire the ignition coil. The HEI distributor is an inductive-discharge-style ignition, but with the points replaced by a solid-state switching device called an electronic ignition-control module.
The module works like an electrical switch, turning power on and off to the ignition coil. This, in turn, causes the coil to generate spark. One of the reasons HEI is able to deliver more spark is that, thanks to the electronic ignition-control module, it can safely operate at much higher current loads. On a points-style distributor, the ballast resistor wire limits voltage and reduces current to the distributor.
Another function of the control module is the management of the dwell circuit. Dwell is the amount of time the primary circuit is closed to let current flow through the ignition coil between each spark.
Long dwell times are needed with inductive ignitions, to allow the ignition coil to become fully charged before firing. This is especially Hook up chevy hei distributor during high-rpm operation, because there is less time to charge the coil between each spark. Since an HEI system produces more voltage and amperage output than a points-style distributor, a larger-diameter distributor cap is needed to prevent voltage from cross-firing inside the cap.
Note that these larger distributor caps also typically incorporate enough room for the ignition coil to be housed internally, making the HEI distributor a self-contained unit. There are a lot of options when upgrading from a points-style distributor to an Hook up chevy hei distributor one. The first is to obtain a good salvage-yard replacement.
Remember, the HEI distributors used the same advance weights, springs, and stops as most of the points-type units, making this a great, economical upgrade.
Be sure to select a replacement distributor with a four-pin control module. The fifth pin was only used on vehicles equipped with knock sensors. Some of the early HEI distributors have a reputation for breaking up at around 5, rpm, so you may want to avoid units made in and Fortunately GM rectified this problem early on by upgrading the ignition modules and coils to offer greater spark energy at these higher engine-rpm levels.
Remember, on a points-style distributor, an inline ballast resistor or resistance wire decreases the voltage from the battery to around 9. Points-style distributors do use 12 volts when cranking. On most and-earlier vehicles equipped an external voltage regulator, there will be two wires providing key-on voltage to the coil.
One wire is hot when the ignition switch is in the crank position, providing battery voltage to the coil. The other wire is hot when the ignition switch is in the run position, providing approximately 9.
Starting invehicles using an alternator equipped with an internally regulated voltage regulator usually did not use an inline ballast resistor, but instead used a resistance wire. Be sure to install an inline fuse in this lead, and solder and shrink-wrap all the connections. If the wiring harness has an inline ballast resistor, or the ignition switch is located in the dashboard, you may need Hook up chevy hei distributor use the cranking bypass wire to supply the distributor with battery voltage when the switch is in the crank position.
You can use a test light or voltmeter to see if your newly installed key-on main feed wire has battery voltage when cranking. If necessary, splice the bypass wire with the new gauge ignition-feed wire and eliminate the ballast resistor. Most aftermarket ignition companies sell matched coil-and-module sets to ensure optimal ignition performance.
Remember to also install new HEI plug wires. The ECM monitored information from various engine sensors, computed the required spark Hook up chevy hei distributor, and then signaled the distributor to change the timing accordingly.
With this system there was no longer a need for vacuum or mechanical advance.
This makes these second-generation distributors impractical for use as a simple HEI replacement. This kit is essentially a Hall Effect trigger, with no external control module.
When using the Ignitor kit, Pertronix also recommends installing one of its Flame-Thrower coils. These coils are black, so if you peel off the label, they look similar to the factory piece. If you plan on running your engine much past 5, rpm, the company recommends one of its full HEI ignition upgrades. These are good up to 7, rpm and come with everything you need to perform an HEI conversion, including the following:. Adjustable vacuum advance with a range of 0 to 22 degrees A new ignition module with wiring harness and capacitor A selection of advance springs and weights An ignition coil A distributor cap with solid-brass terminals and ignition-rotor button.
The process of installing a billet distributor is similar to the stock-HEI conversion method. Even so, I have to admit that there are a lot of advantages to an HEI conversion. Got a question for our Tech Corner expert? Alternatively, you can submit your question via the Web, by emailing it to us at vette sorc. The GM Vortec V8 was introduced in as an alternative to the Duramax diesel for customers seeking maximum "Hook up chevy hei distributor" without the hassles of diesel fuel.
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Hook up chevy hei distributor V8 was introduced in as an alternative to the Duramax diesel for customers seeking maximum power without the hassles of diesel fuel.
Tips and step by step procedures for retrofitting an HEI distributor in your GM if you want to remain factory compliant) and hook it up to the HEI "BAT" terminal.
The second concerns the gauge of wire feeding the HEI distributor. solenoid “R ” terminal to the ignition coil must be retained and must be doubled up with the. Place the distributor cap back on and note which plug wire the to rotate the oil pump shaft until the rotor lines up Street Fire HEI Distributor, Chevy V8.