Nicky B

1971, 350ci, 270hp, auto with Edelbrock performer carb and intake

My car still has the original points distributor and coil fitted and in the interests of reliability and easy starting I am going to switch to electronic ignition.

I don't know wether to replace the distributor with a complete HEI unit or fit a conversion like Pertronix into the old distributor, I'm not worried about keeping the motor looking stock.

Your opinions would be appreciated.

Nick

derekderek

Points wear out about every 20 to 30 thousand miles. Not as a function of time, as a function of how long the engine has been running. How long is it going to take you to put 20 or 30 thousand miles on this car? When electronic ignition craps out, you're dead on the side of the road. I have repaired a bad pair of points not just regapping them I mean fix them with tape when the insulator broke and got home. If you're determined to do this, the complete HEI Distributors on eBay for 50 or 60 bucks do the job just fine. Unless you have a cable tach, which you do. But they also sell HEI with the tach cable output on them. They're a little more money, but still the least expensive alternative.

Big2Bird

The only HEI tach drive I like is the DUI unit from Davis Unified Ignition. They will customize the curve and vacuum advance for the cost of the unit. Pricey, but they work well.

HeadsU.P.

Points do wear. Not so much the contacts but the rubbing block. That changes the dwell as you know. You change the dwell you change the timing. And a bad condensor will leave you stranded just as often as a module unit.

Top of the line is likely a MSD Billet. Next would MSD StreetFire or a Mallory or DUI.
HEI is a no brainer for non-original IGN. Hotter spark, better combustion, gap the plugs wider, better MPG and a little more power. You could snoop around on Summit for prices. Engine & Componets>Distributors>HEI>SBC>Gen-I.

I carry an extra module & tools needed for a roadside swap if neccesary behind the seat for my StreetFire. Not had any issues but these will need timing curved.

Big2Bird

I disagree. A DUI is light years ahead of a Chinese Street Fire.
The DUI can be built tach drive, an Street Fire cannot.
Mallory is not so good anymore.
For years MSD only had tach drive available with their MSD box set up.
Their red "Blaster" coil is a leaky POS.
The epoxy one might be okay, but I haven't tested one yet.

HeadsU.P.

The MSD streetfire is a middle entry level, budget minded unit. Its not $350. Nor is it $60. The MSD StreetFire is made in El Paso, TX. However, their "modges" are made in China. MSD states they will back their China modges.

And BigBird, don't kid yourself. DUI had their own issues with their modules also.

Modules are very sensitive to heat. When a modge is installed, a heatsink compound is applied to the bottom of the unit, supposedly to insulate. Heat breaks the circuits inside the unit causing failure in producing spark. To top it off, the modge is jammed inside an oven (distributor) without any air circulation and very near the exhaust system. They all were proned to fail and have since 1975?
(Now we have coil packs)

Big2Bird

Heat sink compound is a thermal conductor, not an insulator.

The Street Fire is "Made in China."



I prefer Delco modules, but that is just me.

Delco doesn't make a tach drive HEI, but their "Performance" line of Delco HEI are made in Taiwan.

3X2

Convert to T.I. with the new style amplifier board.

Big2Bird

Yep. They make the whole shebang now. Fits right in. I bet $600-800 without looking.

If they put the Chrysler board in the Delco housing, they would have a home run.

3X2

Thermal grease is electrically insulating, but thermally conductive.

derekderek

A heat sink is to draw away heat. Heat sink compound increases heat transfer from the heat source to the heat sink. It is not an electrical insulator. Spread some on the ends of 2 jumper cables. Touch together. How good an insulator is it?

Bullshark

You guys are probably confusing the hell out of the readers of this thread. Thermal compound / grease is typically thermally conductive but electrically insulating. Used to fill the air gaps under power semiconductors etc. The last thing you want is an electrical conductive compound migrating around electrical circuits. Having said that they do make high heat transfer silver filled compounds that conduct electricity to maximize heat transfer, but not typically used unsealed with electronics.

Dump the points, its old technology and cannot be controlled as precisely as an electronic approach.

Bullshark

Big2Bird

You can always tell the fuelies around here.

Let me guess. Crank trigger?

Bullshark

Primoz

I went with breakerless ignition.
http://www.breakerless.com/

Keeps the stock look. Easy to install.
And I must say that I noticed a change in the performance a bit and engine sound.
Probably because my points were bad to start with.

sug

I used the se breakerless ignition from lectric limited . Works great. Every other piece of wiring on my 69 is from lectric limited, dash harness, rear harness, front harness, engine harness and shielded ignition leads .

3X2

Considering the current draw of doing that and how thin the compound is, I'm sure it will conduct. When using it between a module and heat sink, there is negligible electrical conductivity.

Rescue Rogers

I went with pertronix, works great. Had an HEI unit that worked okay too. Its just sitting in a box now

7T1vette

As a professional Reliability Engineer, I would have to disagree with the idea that an electronic ignition is more "reliable". If you put an electronic ignition on a test bench, you can run up a huge number of cycles with no problem. But that's not how it will be used on the vehicle.

It will sit idle most of the time. When in use it will experience temperature swings from ambient to about 300*F (engine heat AND exhaust heat) during each "use" cycle, plus damp conditions, etc. And it will have to repeat this "process" for years.

When an electronic box fails, IT QUITS! No 'limp home' mode.

When points begin to wear/degrade, you can operate the car just fine...it may miss a bit at higher rpm's, but that's what tells you the points need cleaning/adjustment/replacement. In 30 minutes you can install new points/dwell and condenser.

When I drive, I consider "reliability" to mean that my car will get me there and get me back--without significant issue. Electronic ignitions are great....as long as they are working.

P.S. If I NEEDED an electronic ignition (racing, etc.), I would install one. If I just need it for normal use, I'd stay with points.

derekderek

Plus, when you need new points they are cheap, even if you have to go on amazon or ebay to get them. The reason for electronic ignition was emissions and corporate average fuel economy. People can't be trusted to keep their points gapped so that the emissions and the timing are right on. That's why the major manufacturers had to go with electronic ignition.