HEI Conversion from Points
Thread Starter
Navigator
Joined: Jun 2004
Posts: 9
Likes: 0
HEI Conversion from Points
I am looking to convert my 68 Vette ignition from points to electronic.I want good performance,reliability with low maintinence.what should I buy? Any advice will be greatly appreciated! Thanks everyone!!
Duane1
Duane1
Burning Brakes
Joined: Apr 2004
Posts: 1,042
Likes: 202
From: Atoka, TN
i think those mallory hei units are nice. if you get the one with the brass terminals and coil, it's only 159 from summit. it also comes with different springs too. just hook a 12 volt source to it and get an electric tach and you are in business.
chris
chris
Team Owner
Joined: Jul 2004
Posts: 40,412
Likes: 792
From: Redondo Beach, California
Putting a GM HEI on a 1968, in some ways, is easy. However, you do have to provide the GM HEI with 12 volts. The 1968 distributor ..actually the ignition coil.... was provided with much less that 12 volts due to a resistor in the coil positive terminal circuit. You can't use this the ignition coil positive wire to power your HEI. You need a +12 volt wire. (Pardon me if I'm telling you something that you already know..I added these words mainly for people who might not be aware of the difference.)
The big problem is the ...tach. If you want to keep your 1968 mechanical tach you have to buy a GM HEI distributor that has been modified to provide a mechanical tach drive. The last time I looked, these things were about $550. That's really significant bucks.
The 1968 tach can be converted to an electrical drive. It's relatively easy (i.e. not that expensive). There's someone who participates in the forum that will convert your tach. I think that if you install an HEI, you can then alter your tach for an electrical signal from the HEI. However, I'm not sure how you connect an electrical tach to the HEI. Maybe someone else can provide this info???
I'm putting a GM HEI in my 1968 and it has been modified for the mechanical output. I bought this distributor about 12 years ago.
The big problem is the ...tach. If you want to keep your 1968 mechanical tach you have to buy a GM HEI distributor that has been modified to provide a mechanical tach drive. The last time I looked, these things were about $550. That's really significant bucks.
The 1968 tach can be converted to an electrical drive. It's relatively easy (i.e. not that expensive). There's someone who participates in the forum that will convert your tach. I think that if you install an HEI, you can then alter your tach for an electrical signal from the HEI. However, I'm not sure how you connect an electrical tach to the HEI. Maybe someone else can provide this info???
I'm putting a GM HEI in my 1968 and it has been modified for the mechanical output. I bought this distributor about 12 years ago.
Last edited by 68/70Vette; Mar 5, 2005 at 10:18 PM.
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
I have a 74 that I am converting to hei also. I want to share a few websites that have helped me. First is http://www.madelectrical.com/catalog/hei-1.shtml , I’m not sure how hard it is to find the original connectors but this kit has them. The best part is that Mark, the owner, is very nice and knowledgeable. In 74 they used a resistor wire to lower the voltage. This kit includes a wire to use either way.
The second site is http://corvetteclocks.com/page17.html clocks by roger. Basically you remove your tach and send it to him and he converts it to an electrical tach.
I will probably buy an Hei from an ebay vendor. I dont mind if it is a generic brand. I want to spend less than $100.
The second site is http://corvetteclocks.com/page17.html clocks by roger. Basically you remove your tach and send it to him and he converts it to an electrical tach.
I will probably buy an Hei from an ebay vendor. I dont mind if it is a generic brand. I want to spend less than $100.
Last edited by johnt365; Mar 6, 2005 at 01:24 AM.
Instructor
Joined: Aug 2002
Posts: 231
Likes: 0
From: Tucson AZ
Originally Posted by Duane1
I am looking to convert my 68 Vette ignition from points to electronic.I want good performance,reliability with low maintinence.what should I buy? Any advice will be greatly appreciated! Thanks everyone!!
Duane1
Duane1
Racer
Joined: May 2000
Posts: 386
Likes: 0
From: Niedernhausen, Germany
HEI conversion
I have got a HEI distributor with mech tach drive in my 72 - works great! Lucky me, my pre-owner paid for this expensive piece.
However be aware, that you cannot retain your original (if exist) ignitions shielding over the distributor (as the diameter is much larger than the original one). You will need spark plugs with larger gap - 0,045 to 0,060 inches - to obtain the big benefit of a larger spark from it.
Furthermore, the routing of the wires is of more importance with the higher voltage that the HEI puts out: Wires shoud NOT touch ground (=engine) anywhere and also should not touch each other. Recommend wire separator kits and good wires (e.g. MSD helicore).
Regards,
Thomas
However be aware, that you cannot retain your original (if exist) ignitions shielding over the distributor (as the diameter is much larger than the original one). You will need spark plugs with larger gap - 0,045 to 0,060 inches - to obtain the big benefit of a larger spark from it.
Furthermore, the routing of the wires is of more importance with the higher voltage that the HEI puts out: Wires shoud NOT touch ground (=engine) anywhere and also should not touch each other. Recommend wire separator kits and good wires (e.g. MSD helicore).
Regards,
Thomas
Le Mans Master
Joined: Jan 2000
Posts: 8,721
Likes: 108
From: Canada
I have the MSD 6Al with the Petronix II in my original dist. I have ben running this setup for 3 years now and am very pleased with it. The new MSD e-curve is new and might be worth looking into as well. http://www.msdignition.com/2005/2005_4.htm I don't know anyone running this yet but it sure looks good on paper. 
Intermediate
Joined: Nov 2002
Posts: 30
Likes: 0
From: Friendswood Texas
Thanks for the info. I installed an HEI and used the same wiring and have had problems with a real gassy odor. I have checked the plugs and they show a rich condition. I was just about ready to change carburetors and intake to see if that helped. I think now I have found the problem. Thanks again.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Heel & Toe
Joined: Sep 2004
Posts: 20
Likes: 0
From: Aiken SC
GM HEI with Mechanical Tack
I found a GM HEI with Mechanical Tach on-line at http://www.hotrodsusa.com/store/product2158.html. Its $289 which is a lot less than I've seen elsewhere. Has anyone tried this product?
Instructor
Joined: Mar 2004
Posts: 188
Likes: 0
From: La porte Texas
We took my stock single pt. dist. and built a small cap HEI . Looks stock , everything stock works. I had to run full 12v. wire from fuse block. I run .045 gap. I think it idles and runs better .
