HEI Distributor/ TACH

Yonco · 03-15-2007, 11:09 PM

I installed a HEI distributor in my 71 302. Im having problems getting the tach to work on the car. It has the 8k rpm In dash tach. I have the guage cluster out of the car just to test it and see if the tach works( was working b4 the hei swap) There is a 2 wire coming from the back of the tach, and +12V and a tach wire( to coil) on the new HEI, there is a tach port.I hooked the 12V to a 12V in the fuse area.Then itook the tach wire that was on the coil and hook it to the HEI disty. But that does not work. When it touches, the car stalls. Where should i be hooking these wires? -Jon

JMD · 03-17-2007, 05:57 PM

On the hei setup, there are two terminals that exit the cap, one is for dist power the other is for the tach. You can not hook the tach wire to the power wire.

You probably already knew this but I thought I might post this anyway, just in case.

LCC · 03-17-2007, 10:28 PM

There was somthing years ago that I came across about hooking an HEI to an autometer tach that you had to use a resistor depending on the model of HEI.....or something. I ended up calling the company about it and they sent me the right drawings. Do you know if the tach output is points or mag pickup?

67t5ponycoupe · 03-17-2007, 10:39 PM

Don't know about the stock tach but I'm running an HEI from summit with an Autometer Phantom tach and it hooked up and worked just fine.

Yonco · 03-17-2007, 10:55 PM

Im running a 65$ ebay HEI( works good) im not complaining! and the stock 8k RPM tach that came with 1971 mach 1's -Jon

67t5ponycoupe · 03-18-2007, 04:35 AM

I did some looking around and found this
A Note From The "Tachman" on Pertronix"
In the last several months I've had many requests to convert pre-1974 Ford tachometers to GM HEI. In 27 years of authorized Ford service I could not figure this out; since I consider Ford's in-line tach hookup to be the most reliable and accurate system. However, through many intelligent clients I've talked to, I found out that Pertronix is now offering their reliable electronic conversion kits for 1974 up Fords. In 1974 FoMoCo changed how they derive their tach signal from the coil. Ford switched to the same style as G.M. and Mopar. I found out many 1973 back clients did not understand what they were installing or purchasing. If you own a pre-1974 Ford tachometer, make sure you know what you are ordering. The 1964-73 Ford in line tachs will not work with the HEI distributor Pertronix is offering. They need to be converted and the Tachman can do this, but it is not necessary!!! All 1964-73 Ford Tachs need the following system!!!!!

I know you are not running pertronix but the part about the pre 74 tach's being in line is interesting. I would have to assume that means the +12 volts feeds the tach and then the tach feeds the distributor its power to run the points. That would mean that you will not get your tach to run with that HEI. Here is a link to the site I got that from. You might find something to help you there. http://www.tachman.com/ford.htm

Yonco · 03-18-2007, 08:11 AM

damn.