Ignition Points or Aftermarket Electronics?

[pajeff02]

Our '74 Corvette L-82 is currently equipped with the stock distributor (P/N 1112150) and a dual point setup from Accel. I switched over to a mini-starter when the engine was installed and wasn't thinking about the 12 volt feed to the distributor. During cranking, the starter feeds full voltage to the points, but once the key is released power is then fed through a resistor wire that cuts the voltage down. This helps with points longevity as full voltage will often fry them in short order. Other makes, Dodges in particular, use a device called a "ballast resistor" in place of the resistor wire that GM's have. As a result of my oversight, I now run reduced voltage to the points during cranking.

I did try a Crane XR-i points replacement module in the distributor, but no matter how we adjusted the gap the timing was erratic and wandered up and down by about 5 degrees at idle. Putting the points back in, the timing was rock steady so we opted to run them in lieu of the Crane unit to get the car on the road. With my current track record for stuff breaking down on this car, I admit that the points setup makes me just a bit nervous on trips of any distance. I have considered upgrading again, but my experience with the Crane XR-i was less than good. I know that Pertronix has made points replacement units forever, and I also see units by Accel and Mallory. Anyone have experience with these? Recommendations?

[Orcus79]

While I can't speak from experience, I can from observation. Dad recently rebuilt the engine in his Chevelle (72 LT1 block built to the 9s), replacing the dual points with an electronic MSD system. Night and day difference in the way the engine runs. Lot smoother idle with a pretty hot cam in it.

Then you can bypass/remove the wire for a full 12V

[SMWS6TA]

I too was going to suggest the MSD unit.

FBJ seems to work with the classics a lot, I would ask him see what he suggests.

[pajeff02]

Are you guys talking about a full ignition box -- like a 6AL?

[Orcus79]

I'm not sure what dad is running, I don't think it's a full ignition box, haven't looked all that close sorry. I was miles away when everything went to together. They do have digital distributors that are a full swap it seems. Thats would be my suggestion any who.

[Firebirdjones]

Our '74 Corvette L-82 is currently equipped with the stock distributor (P/N 1112150) and a dual point setup from Accel. I switched over to a mini-starter when the engine was installed and wasn't thinking about the 12 volt feed to the distributor. During cranking, the starter feeds full voltage to the points, but once the key is released power is then fed through a resistor wire that cuts the voltage down. This helps with points longevity as full voltage will often fry them in short order. Other makes, Dodges in particular, use a device called a "ballast resistor" in place of the resistor wire that GM's have. As a result of my oversight, I now run reduced voltage to the points during cranking.

I did try a Crane XR-i points replacement module in the distributor, but no matter how we adjusted the gap the timing was erratic and wandered up and down by about 5 degrees at idle. Putting the points back in, the timing was rock steady so we opted to run them in lieu of the Crane unit to get the car on the road. With my current track record for stuff breaking down on this car, I admit that the points setup makes me just a bit nervous on trips of any distance. I have considered upgrading again, but my experience with the Crane XR-i was less than good. I know that Pertronix has made points replacement units forever, and I also see units by Accel and Mallory. Anyone have experience with these? Recommendations?

WOW, have I been down this road too often

You are correct in that GM uses a wire from the starter solenoid hooked to the "R" terminal and runs directly to the coil, that supplies a full 12 volts during cranking ONLY. Once you let go of the key in the crank position, only ~8-9 volts are supplied through the resistance wire that runs from the fuse block.

I wasn't sure if you were asking if this is correct or not, so just tossing it out there that this is in fact the way GM designed the system and it works perfectly.

Boy this response is going to get winded......

I run points in 5 different cars here. I like to use good quality points from Accel that have the solid contact points, not the cheap hollow contact junk. These points will last for years, and you can simply file them and reinstall. I can't say the same for the cheaper hollow contacts.

Anyway, my experiences with some of the aftermarket modules haven't been great, sort of hit and miss. I used Pertronix a couple of times. On my wifes vette it worked fine so I left it be. On my Firebird I had nothing but issues. It ran fine on back roads, but once on the highway for extended RPM the module would get hot and shut down. Left me stranded until it cooled off. I had to drive a 70 mile stretch at 10 mile spurts at a time,,,,frustrating.
Pertronix was a stand up company, covered the module after they tested it and found it was faulty. The new one however did the exact same thing so I sent that one back too. Again they tested it, found it faulty and sent another one. Keep in mind that every time this happened the car was down for more than a week,,,NOT GOOD. That last pertronix they sent never made it back on the car, it has been sitting on the shelf ever since,,,,I went back to the points and haven't had another issue with the car Since then I've stayed away from Pertronix.
The other issue I didn't like about Pertronix was that the dwell seemed to fluctuate and it would move my timing around (just what you are experiencing Jeff) I also never got quick starts either and always had to crank the engine 4-5 revolutions before it would hit. The whole thing was just a frustrating experience. With points my dwell is rock solid, and timing is also rock solid.
I've also used the Mallory Unilite setup before. Worked fine but the module is very sensitive to voltage spikes, and every time I jumped the car with another vehicle it would fry that module. Got to the point I didn't trust the thing on long trips so it also came out.

Went back to points and never looked back. With a good set of points, and a good distributor that isn't worn (and shim the gear to about .010-.012" ) You'll never have to touch those points. Points in the mustang are 30 years old and still kicking Haven't changed them in my Firebird since 2004, and checking with a dwell meter they haven't budged. Sandrail has the same points that were installed in 1985ish, not bad for a VW huh? Frankly they are really trouble free, and I've been thousands of miles away from home in that Firebird and I don't even flinch about it.
Besides that, if you are truely worried about it, you can always carry an extra set of $10 points with you, they are easy to swap. I don't know anyone that carries an extra Unilite or Pertronix setup with them Because there will come a time when that electronic stuff will fail,,,,and it will happen, that's murphys law

For the cars that I absolutely have to run an electronic setup in, I prefer a complete MSD billet distributor setup with a multispark discharge box. I've run those for many years without a hickup. Top notch stuff. But it doesn't look original, however it's easily hidden, they make a stock female distributor cap that even has a fake "points" window in it,,,and you can paint the cap black Hide the wires and the box,,,the only detecting feature is the shiny billet machined distributor shaft,,,,but you can scuff that up with a scotch brite pad..
But you didn't hear any of this from me

[Firebirdjones]

I re-read that Jeff and realized you put a mini starter on. I guess you found out those solenoids don't have the "R" terminal like the old stuff.

Actually now, while cranking, that resistance wire from the fuse box goes dead when in the crank position, which is why there was a wire on the "R" terminal that went hot at that time to feed the points with some juice.

It will still work, although you might find that you'll be cranking the car a little more as it may not fire up as quickly on the first hit of the key.


I wanted to also mention, the gain in performance and mileage that pertronix and others claim when switching from points with their claims of hotter spark and better coils with more dwell time etc..........BOGUS

At that time I was running my firebird in pure stock and I was always looking for ways to gain that extra tid bit of HP while still being pure stock legal. I've raced this car so much I have it tuned and dialed in squeaking every bit I can out of it. Decided to switch to the Pertronix. The car didn't run quicker, not one tiny bit, nor did it MPH any faster,,,,at all. Oddly enough it also would never start as quickly either. Always had to crank the damn thing 4-5 revolutions before it even tried to hit. With the points, I look at the key and the sucker fires off, and that's not that far of an exageration. Literally hit the key and you barely here the starter turn not even a full revolution.

Honestly I feel points are the most dependable ignition system out there. Isn't really much that can happen, it's just a contact. I've never had a set fail me in 30+ years. The only time they won't fire is if the contact is corroded, and it has to be pretty bad. I've only had that happen on the cars that have sat here and never started for 25+ years. But 2 minutes with a file cures that.
Only thing igntion related that left me stuck was the coil going bad, and that can happen with any ignition system. It's an easy fix at any parts store. But hey,,,that coil was the original 43 year old coil so I can't complain

[pajeff02]

Well FBJ... that has to be your longest post ever on the site!

I don't have a problem with the points. They have worked just fine since we installed them, even with the 12 volt trigger not hooked up to start the car. I guess I was hoping for the "throw it in and forget about it" type of upgrade, but with the info you posted I may as well just stay with points. I do run the heavy duty Accel points as you stated. I'll probably just toss a cheap set in the storage bin for backup and forgo any electronic upgrade. I really do not have an interest in running an ignition box on the car, it was just the points that I was concerned about. Thank you for taking the time to lay it all out.

[Firebirdjones]

Well FBJ... that has to be your longest post ever on the site!

I don't have a problem with the points. They have worked just fine since we installed them, even with the 12 volt trigger not hooked up to start the car. I guess I was hoping for the "throw it in and forget about it" type of upgrade, but with the info you posted I may as well just stay with points. I do run the heavy duty Accel points as you stated. I'll probably just toss a cheap set in the storage bin for backup and forgo any electronic upgrade. I really do not have an interest in running an ignition box on the car, it was just the points that I was concerned about. Thank you for taking the time to lay it all out.

Ha.
If you really want electronic you could always find an HEI to drop in. Easy and cheap. They are just bulky and an eye sore and a bit of a pain to work on. However being a 74 vette it won't fit behind your ignition sheetmetal covering (if you still have that on the car)

A better alternative would be the "ready to run" MSD distributors that don't use a box. Very slick setup, and the digital version has electronic dials to turn and control the amount of centrifical advance and vacuum advance with a little screw driver. This distributor is small (points distributor size) and a very clean install.

[pajeff02]

The ignition shielding is on a shelf in our basement -- I only have the distributor shield and its brackets. The other pieces were missing from the car when I started the restoration. I do run the stock tach drive distributor and the aftermarket HEI versions are a bit pricey. I have an Accel adjustable vacuum advance unit on it as well. I have a picture of us setting up the distributor on an old school Sun Distributor bench that you would probably like... but it is in print rather than digital format.

[Firebirdjones]

The ignition shielding is on a shelf in our basement -- I only have the distributor shield and its brackets. The other pieces were missing from the car when I started the restoration. I do run the stock tach drive distributor and the aftermarket HEI versions are a bit pricey. I have an Accel adjustable vacuum advance unit on it as well. I have a picture of us setting up the distributor on an old school Sun Distributor bench that you would probably like... but it is in print rather than digital format.

Cool, I have a sun machine from the mid 60's here as well. They work great. Also have the large by huge Sun diagnostic machine here that still works.

[pajeff02]

My friend has the same as well. Going to his garage is like going back in time. It's an awesome trip.

[67CamaroRSSS]

FWIW, I always had great success using "Blue Streak" brand points and condenser. On a new set they'd work fine up to about 7k RPM before I got any point bounce. They're pricey but worth it.

The 454 in the 67 has a Unilite that I bought back in 84. Only item I ever had to replace (besides the cap and rotor) was the ignition module at ~60k miles.

IMHO, I'd stay with the factory point type dizzy as it also has the tach drive. Just use good brand name points, set it up correctly and it should work for 6-10k miles (more???) without a hitch.

[pajeff02]

Sounds good. I have the heavier Accel points in it now. They seem to be working fine. I am going to pop the cap for a visual inspection and throw a timing light on it here sometime.