tiger

I have an old points type distributor, and seperate induction coil in it now. I have an HEI distributor out of a '79 Caprice. The HEI never gave me any problems. Other than the wiring harness connector being different, are there any real problems with making this swap? The HEI is a vacuum advance unit. I will likely have to visit a junkyard to get the HEI connector and a reasonable length of wiring. Then just figure out how the '69 harness wires would mae up to a ten year older distributor. I am sure some of you have done this. Is there a websaite that describes it? Thanks :jester

PatsLs1vette

Its no big deal just run a 10 guage wire from the fuse box thats switched on with key only and also make sure it has 12 volts when cranking too.Or you could tap into into your ignition swicth under the steering column too.You can tape up your old harness wires and tuck them down deep so its hidden and run a vacuum hose to your carb. for ported vacuum.Only thing is your tach will no longer have a mechanical drive so it wont work.


[Modified by patsnitrovette, 4:18 PM 8/30/2003]

The Money Pit

I had points on a 327 with the Chevy 151 cam that would bounce at just over 5000 rpms. Dropped in a junkyard HEI,and could tach 7000 with ease. The advance curve may need tweaking once you get it in,but the install is straight forward. The old points system did use a limiting resister on the primary coil circuit,so eliminate it,or use a different ignition switched 12vdc source to the distributer. This should be the only wiring change required,except the tach connection.

Larry B.

You are going to loose your Tachometer. None have a cable drive.


[Modified by bluevetteman, 8:21 PM 8/30/2003]

PatsLs1vette

actually performance distributors and msd have a tach driven hei you could go with if you wanted to spend the bucks.

Jack71

I think there was a stand at Carlisle that rebuilt points into electronic.

I went with the MSD and love it.

litevette

Patsnitro is correct, there is a cable drive hei, but it's VERY expensive!!!

Bob Turner

Tiger,

I am doing this HEI conversion as well; please let me know where you are tapping in for 12+ switched power when key is on (and when key is in "start" position...)

Thanks,

Bob :cool:

Smokehouse69

Bob, I did this conversion last year, and I didn't bother trying to find the "right" kind of power, I got a $5.00 relay from Radio Shack and hooked it up so that it latched up from the old resistor wire circuit that went to the old points coil. Then I hooked the other leg of the circuit to the 12V terminal on the starter. Now when I turn the key to start or run, the old resistor wire circuit pulls down the contacts that activate the full 12v to my HEI distributor. It reads as being more complicated than it really was. It took me about 30 minutes to install the setup. I also put a 20 amp fuse in the 12v line, it was probably overkill, but I never like to install un-fused power to anything.

Smokehouse69

Tiger, there is a guy that will convert your old tach drive distributor to HEI, fairly reasonably. http://www.davessmallbodyheis.com
Just something to keep in mind as a cheaper alternative to a new tach drive HEI or an MSD tach drive distributor.

markdtn

Clocks by Roger will convert your tach too, or you can find a 75-77 tach and install it with the associated wiring-but it has a different appearance than yours. You may have trouble with interference on the washer motor as well.

tiger

Thanks for all the replies, folks.

Here's what Tiger did this past long weekend. Took off the eight plug wires, and the wire from the center of the cap to the coil. Next, removed the cap. Then loosened the hold-down bolt (9/16"), and removed the hold-down (kind of a fork shaped clamp). Before pulling the distributor out, I disconnected a black wire, with spade terminal end, from what looks like the condenser. Then I removed the rubber grommet on the bottom of the distributor. Then pulled that wire out. Next, I pulled the distributor, and set it aside. I loosened the induction coil bolts and bracket, (1/2") and the two brass nuts on the top of the coil (3/8"). I taped up the three wires, all of which were black (probably not factory correct), and tucked them out of the way.

Next, I had to fiddle with the HEI to know which terminal to apply power to. Man, I must sound like the biggest Bubba to have ever lived. Anyhoo, on the tailgate of my wife's truck, I sat a car battery, the distributor, a spark plug wire with plug in it, some vise grips, and a length of 12ga wire that had a slotted connector already crimped on. The HEI has a three wire connector that goes from the distributor body to the cap. It can only go on one way (Thank God!). That leaves two other connections on the cap. I know one has to be +12, the other is probably a tach signal. After grounding the distributor body, and plugging the plug wire into one of the eight terminals, sitting the plug very close to the ground terminal of the battery, and trying power to one of the two terminals, I rotated the distributor body, and got a very strong spark. There's no sense in installing a distributor without testing it first. So the only connection that must be made is to the terminal that if you were looking down on the distributor, would be in the more-counter-clockwise position. I hope that makes sense.

I ran power to it (for testing) straight to the terminal on the horn relay that goes to the starter solenoid. More on this faux-pas later.....

To set the timing, I removed the driver's side valve cover, and bumped the starter until: 1) Both #1 cylinder valves were closed, i.e. the rocker arms were loose, could be wiggled back and forth without too much effort, and 2) the mark on the balancer was lined up (closely) to the metal timing mark on the timing chain cover. Once that mark is there, it will indicate that either #1 or #6 is in firing position. That is why the need to remove the valve cover and check for the orientation of #1's valves. At this point, #1 is pretty close to being in firing positiion, and so I put the HEI cap on, and #1 cylinder's wire to the cap.

Set up the timing light, and wiggle the distributor, watching the timing light flash. This has to be done with jerky movement. If you rotate it slowly, the hall effect sensor doesn't register it for some reason. Once I was feeling pretty god about how close the timing was, I put the cap on, put the other 7 plug wires on, and tightened (not completely) the hold down clamp.

Started engne, and made fine-tune adjustments with the timing light and rotating distributor. It turns out, this distributor has very little to no centrifugal advance. The vacuum advance was working , as I put the ported vacuum line to the solenoid, it had an effect on the timing. I'll have to dig into it and play with the weights/springs. This engine definitely is starving for more ignition advance. The distributor came out of a Caprice, so maybe there's a difference between how the two engines were timed.

Oh yeah, after a trip around the neighborhood, I park it in the driveway, turn the key of.... Engine is still running (WTF?) Then I remembered. So right now my method of shutting the car off is to open the hood and yank the wire to the distrubutor cap. Bubba would be proud...

Oh yeah, for a more "permanent" solution, I intend to run a line from the starter solenoid, to replace the one marked "20 Y". I assume there is a resistor along that path somewhere, because I measured 6.5 volts going to the induction coil I took out. I'll let the Misses help me find a key-switched source of 12 volts. It's under the hood somewhere. I'll find it...
:jester


[Modified by tiger, 2:13 PM 9/2/2003]


[Modified by tiger, 2:14 PM 9/2/2003]

terry82

if you use the pertronix ignitor kit [replaces points]you would still have your tach

Bob Turner

tiger!!

Let us know where you tap in for 12+!!! I am doing the same swap this week except with a new distributor from Jeg's......

Bob :cheers:

Bob Turner

Hey Tiger,

What did you end up doing as a permanent solution?

Bob :cheers:

Bob Turner

:confused:

aussiejohn

tiger,
I was very concerned to read about your testing method with the battery. Wet cell batteries produce hydrogen gas, and firing a spark plug in the near vicinity is dangerous. Remember the Hindenburg? Please don't ever do that again. I'd hate to see you change your handle to "scarface".
Otherwise, keep up the good work. :cheers:

Regards from Down Under

aussiejohn