The Stovebolt Site Forums The Shop Area The Electrical Bay '58 HEI conversoin

I have a 283 with GM HEI/internal coil. My new wiring harness is stock except for accomodating an internally regulated alternator. I have a key start, two position ignition switch, I1 & I2. My instuctions for wiring harness show an 18 gauge green wire from IGN2 to Igniton Resistor. And another 18 gauge green wire from IGN2 to Coil +terminal. IGN1 wired with 18 gauge brown wire to ignition resistor. My question is: Can I just hook up the 18 gauge green wire from IGN2 to the HEI Bat terminal, or is it more complicated.

not sure you need heavier wire, all the original ignition/coil wiring is 20ga, but when eliminating the ign resistor you'll need to jumper terminals on the key sw, otherwise you won't get power to the coil except when cranking, because the stock switch wiring setup is to bypass the resistor when cranking, then power it thru the resistor .... best to use an ohmmeter on the switch and see what configuration gives coil power on both run and crank

Bill

I would run a 12 gauge wire from ign. 1 to the HEI bat. connection. If it doesn't want to start till you turn the key back to run position, you will want to run the wire off both 1&2.

does the HEI really need a wire as heavy as the alternator output? everything I've seen says they might draw a momentary 20amps at startup. 5-8 normal operation

http://cyberdave.org/HEICoilInfo.html
http://www.powerstream.com/Wire_Size.htm

Bill

Thanks for responses. So, if I run a 12 gauge wire from IGN2 to the HEI "BAT" terminal, and leave the 18 gauge wire from IGN2 to ignition resistor and 18 gauge wire from IGN1 to ignition resistor, does that sound OK? I know wiring diagrams show 20 gauge wires for these applications in light trucks, but my Classic Parts harness uses 18 gauge.

the resistor must be eliminated with an HEI

Bill

Pat, check this site.

http://www.chevytalk.org/fusionbb/showforum.php?fid/72/

It is a Chevy performance forum almost entirely dedicated to drag racing issues. I am not a member but I read it for amusement and information. Like all of these forums, it is a mix of crackpot opinions and expert information.

There is a guy whose handel is Ignition Man and he has posted an unbelievable amount of information on the HEI ignitions and how to optimize them. Not only is your question about wiring addressed by Ignition Man but he explains the best plates, weights, springs and vacuum cans to use and how to adjust and modify them for the best perormance in your application.

He is very opinionated about various aftermarket HEI systems, some of which come from, you guessed it, China.

My street rod is a 350 SCB powered '32 Ford roadster and I am running an OEM Chevy HEI with a Crane Cams adjustable vacuum can and mechanical advance spring kit. Even on a mild street rod like mine or a daily driver optimizing the distrubutor advance curve greatly improves performance and fuel economy. My dyno for making these and other tuning adjustments is a long grade near my home. My wife listens for ping and I read the plugs at the top of the grade. It's a crude but effective laboratory.

Have fun!

I am a little interested, through internet search, by the use of a relay under the hood to provide current to the HEI. One fused wire from the battery to the relay, One wire from the relay to the HEI, a ground, and wires from IGN1 and IGN2 to the relay to turn it on. The argument is the HEI never has to share power with any thing else. With wires from both ignition terminals to the relay, it gets power in start and run modes. Seems logical and sounds easy to set up. I'm still debating.

I like to run the relays on a lot of things but I don't think it is necessary on the ign. They don't pull all that much current & it's a short distance from the switch.