How long has the HEI system been used?
The GM HEI system was used in GM vehicles for a approximately 20 years. It is a simple design using a magnetic trigger, electronic controller inside the cap, and a coil. A nice feature of the HEI is the coil is integrated right into the distributor cap, meaning no coil wire.
What are the components of a HEI distributor?
There are three main components in an HEI: the ignition module, the pick-up coil and the integral high-tension coil. The other components of the distributor, such as the mechanical and vacuum advance, gear drive and shaft, are all very similar in function to those found on a breaker-point system.
What should the HEI reading be on a GM car?
The reading should be between 500 and 1,500 ohms. Make sure to jiggle the wires with the meter attached to test for any breaks. There are three main components in an HEI: the ignition module, the pick-up coil and the integral high-tension coil.
How does Hei work in a points ignition system?
In a points ignition system, as the engine speed increases, the available energy to meet the demand of the spark plug decreases. HEI eliminated this problem by removing the resistance wire and applying full alternator output to the primary circuit.
How do you remove a HEI distributor from a Chevy?
Soak with penetrating oil and work carefully to avoid damaging the bushings. With the shaft out, the pick-up coil and pole piece assembly can be removed by carefully removing the snap ring from the upper end of the bushing. Once the distributor is fully dis-assembled, thoroughly clean everything.
When to remove cap from Summit HEI distributor?
Once you feel compression building, look for the zero mark on the harmonic balancer to approach the timing tag. We prefer to set the initial timing for most engines at 10 degrees Before Top Dead Center (BTDC). With that set, remove the cap from the distributor. We’re using a Summit HEI distributor.
What should the voltage be on a HEI distributor?
Disconnect the green and white wires from the module and touch the positive meter lead to the green wire and the negative lead to the white wire. The normal reading should be between 800 – 910 ohms. Testing the primary circuit of the coil. The remaining electronic part that would keep the distributor from firing is the module.
What are the benefits of converting a GM points distributor to Hei?
With the exception of firewall clearance problems in various vehicles, this should apply to swapping most any GM points type distributor to HEI. Some benefits from the HEI swap include reduced maintenance, easier starting, and often a small improvement in gas mileage.