Replaced the dual point with HEI

[chewy]

My old 65 dart was having issues with the dual point on a cruise last month after rebuilding the carb. Loss of power was apparent. Upon troubleshooting, vacuum advance was having issues.

Got a rebuilt replacement vacuum adv from @halifaxhops and proceeded to tune the points. The old advance actually had gassy oil in it O_o.

As I got the dwell set, one of the leads inside broke loose. Having repaired that lead a few times it was too short to fix again. So also got some new leads from Ray as well.

Got it all together and running, combined dwell was 36. But, as I had put the new leads in, the inside insulator block cracked in half. Still bolted in, but worried if I loosened the nut on the outside even a little, it would fall apart.

So I decided to make the jump and try out HEI again, with one of the new replacements available. I had tried the do it yourself version of the HEI conversion years ago with a module, mopar electronic dist and a coil, and it never performed better than the dual point.

Rotated the distributor/oil pump gear 90 to install it. Put a solid copper wire in a spare ballast in place of the resistive wire and installed it. Replaced the GR5 plugs that were running rich with some GR4IX's gapped at 0.050, and proceeded to tune in the new HEI distributor and coil.

I found out tuning it, that the advance range was way too wide to get the engine to run right. Setting timing to get the total advance that I wanted would have been 4 ATDC. Backfire and flames in the newly rebuilt carb was the result at that setting when giving it gas, stumble and backfire through the carb. Putting it on the vacuum port instead of the dist port, it just stumbled, no flames...

Ended up disconnecting the vacuum advance on it and plugging the carb vacuum ports.

The old dart runs considerably better than the dual point ever had now. Timing at 8 BTDC with total advance at 36. Now that its dialed in, I'm pretty impressed with the result. Glad I did the swap.

Ready for the mopar club meeting this week.

 

[chewy]

 

[Darter6]

Had the same problem when I did mine. Ran fine with the vacuum advance disconnected.
Then adjusted the vacuum advance with a 3/32 allen thru the port 1/2 turn out. Took away the stumble off idle along with the annoying backfire that would happen on occasion .
Tell Smilin' Ed hi for me. I e-mailed him today.

 

[George Jets]

My old 65 dart was having issues with the dual point on a cruise last month after rebuilding the carb. Loss of power was apparent. Upon troubleshooting, vacuum advance was having issues.

Got a rebuilt replacement vacuum adv from @halifaxhops and proceeded to tune the points. The old advance actually had gassy oil in it O_o.

As I got the dwell set, one of the leads inside broke loose. Having repaired that lead a few times it was too short to fix again. So also got some new leads from Ray as well.

Got it all together and running, combined dwell was 36. But, as I had put the new leads in, the inside insulator block cracked in half. Still bolted in, but worried if I loosened the nut on the outside even a little, it would fall apart.

So I decided to make the jump and try out HEI again, with one of the new replacements available. I had tried the do it yourself version of the HEI conversion years ago with a module, mopar electronic dist and a coil, and it never performed better than the dual point.

Rotated the distributor/oil pump gear 90 to install it. Put a solid copper wire in a spare ballast in place of the resistive wire and installed it. Replaced the GR5 plugs that were running rich with some GR4IX's gapped at 0.050, and proceeded to tune in the new HEI distributor and coil.

I found out tuning it, that the advance range was way too wide to get the engine to run right. Setting timing to get the total advance that I wanted would have been 4 ATDC. Backfire and flames in the newly rebuilt carb was the result at that setting when giving it gas, stumble and backfire through the carb. Putting it on the vacuum port instead of the dist port, it just stumbled, no flames...

Ended up disconnecting the vacuum advance on it and plugging the carb vacuum ports.

The old dart runs considerably better than the dual point ever had now. Timing at 8 BTDC with total advance at 36. Now that its dialed in, I'm pretty impressed with the result. Glad I did the swap.

Ready for the mopar club meeting this week.

There's that 8° BTDC again with the HEI and E-core coil.

Good on you for figuring out why it needs to be 8° on that setup.


☆☆☆☆☆

 

[chewy]

Had the same problem when I did mine. Ran fine with the vacuum advance disconnected.
Then adjusted the vacuum advance with a 3/32 allen thru the port 1/2 turn out. Took away the stumble off idle along with the annoying backfire that would happen on occasion .
Tell Smilin' Ed hi for me. I e-mailed him today.

I updated him today on the dart and the progress since we got together a couple weeks ago. Will tell him.

 

[Bewy]

If you are using the factory coil, you should keep the bal res, even with HEI.. Coil will run hot without it & may burn out.
What the coil 'sees' with breaker points: an on/off switch.
What the coil 'sees' with HEI: an on/off sw, same thing.
If you want to get the best from your HEI [ more spark energy ], use a low resistance E core coil such as MSD #8207 [ without the bal res ] & open the plug gaps to.060".

 

[chewy]

If you are using the factory coil, you should keep the bal res, even with HEI.. Coil will run hot without it & may burn out.
What the coil 'sees' with breaker points: an on/off switch.
What the coil 'sees' with HEI: an on/off sw, same thing.
If you want to get the best from your HEI [ more spark energy ], use a low resistance E core coil such as MSD #8207 [ without the bal res ] & open the plug gaps to.060".

Thanks. And agree. Distributor instructions said not to use the points coil with it. Using the 45000 volt electronic coil that I picked up with the distributor.

Didnt.know I could take the points that wide. Will give 0.060 a try. Appreciate it.

 

[chewy]

Regapped the plugs, still runs great in the garage. Raining now, will test drive it tomorrow between storms when the road dries out.

 

[halifaxhops]

You need to run a .3 ohm coil with the heI not a 1.5 stock coil.

 

[MadScientistMat]

HEIs do not use ballast. Unlike the stock ignition, they are off when the key is off, so they don't overheat there. And when running, they vary the dwell time to limit current. They simply start the dwell late enough that the current almost never exceeds the module's target. Coils don't instantly go to full current when turned on; it takes time for the current to build.

 

[chewy]

HEIs do not use ballast. Unlike the stock ignition, they are off when the key is off, so they don't overheat there. And when running, they vary the dwell time to limit current. They simply start the dwell late enough that the current almost never exceeds the module's target. Coils don't instantly go to full current when turned on; it takes time for the current to build.

That's why I made a fake ballast so I could have the firewall look stock. At some point I'll pull the distributor and paint the base flat black as well.

It's pretty easy to push the blades and ballast wire out of an old resister block and solder in a solid copper wire from a piece of romex and put it back together.

 

[Bewy]

Man, is there some false information in this thread:
[1] If the coil being used with the HEI is a stock coil that used a bal res, then the bal res should be retained to protect the coil from overheating/failure.
[2] If it is an aftermarket coil that is supposed to be used with a bal res, then the bal res should be retained...unless the manufacturer says otherwise.
[3] You can run a 0.3 ohm or 1.5 ohm coil with HEI. The HEI will provide max performance, ie energy output & dwell control, with the lower res coil. But both will work.
[5] Dwell time does not limit current with HEI; it limits the time that the coil receives maximum [ saturated ] current. Max current is limited internally with HEI.
[6] The dwell [ time period that coil current is flowing ] is started earlier, not later, so that at higher rpms when the time interval to charge the coil is shorter, there will be enough time to fully saturate the coil.

 

[chewy]

Man, is there some false information in this thread:
[1] If the coil being used with the HEI is a stock coil that used a bal res, then the bal res should be retained to protect the coil from overheating/failure.
[2] If it is an aftermarket coil that is supposed to be used with a bal res, then the bal res should be retained...unless the manufacturer says otherwise.

The manufacturer says to use an e coil 45KV or more, and 12V wire to coil no ballast. Not doing so will void the warranty on the distributor. That's exactly how I installed it.

 

[MadScientistMat]

Man, is there some false information in this thread:
[1] If the coil being used with the HEI is a stock coil that used a bal res, then the bal res should be retained to protect the coil from overheating/failure.
....
[5] Dwell time does not limit current with HEI; it limits the time that the coil receives maximum [ saturated ] current. Max current is limited internally with HEI.

Um, no. I've used an oscilloscope and current probe to view current draw on lots of different coil types. I've never seen one go to full saturated current the nanosecond you start dwell. They typically take around 6-8 milliseconds to reach full current, sometimes more.

Now if you limit the dwell to 2 or 3 milliseconds, you get a lot less current, no ballast resistor needed. The ballast resistor in this scenario slows down the time it takes to reach maximum current and reduces your spark energy.

Ignition systems that control dwell limit current on their own with the ballast resistor not need or wanted.

 

[Bewy]

I never said the coil reaches full saturation instantly with HEI. It takes time. That time taken is what limits the use of a single coil when it has to fire a lot of cyls [ 8?] at higher rpms. It runs out of time. A CD system uses a capacitor to charge the coil & with a cap there is no time delay & they can to higher rpms.

 

[MadScientistMat]

Maybe not in those exact words, but all your arguments for a ballast resistor with HEI use the premise that the coil is reaching full current. And it isn't. A genuine HEI module (I can't speak for every knock off) uses current sensing to ensure the dwell time only allows the coil to reach a point below maximum.

 

[slantsixdan]

Neato, but spare some love (and time, and attention/work) to your cap and rotor especially if you're going to run big-*** plug gaps. Detailed info in this long (but worthwhile) thread. Written for 6-cylinder applications, but applies even more so to 8s because of the narrower/tighter spacing between adjacent contacts in the cap. Even factory HEI setups without the coil-in-cap arrangement use a big-diameter cap to space out the contacts.

(…and make sure you've got good plug wires)

 

[chewy]

Neato, but spare some love (and time, and attention/work) to your cap and rotor especially if you're going to run big-*** plug gaps. Detailed info in this long (but worthwhile) thread. Written for 6-cylinder applications, but applies even more so to 8s because of the narrower/tighter spacing between adjacent contacts in the cap. Even factory HEI setups without the coil-in-cap arrangement use a big-diameter cap to space out the contacts.

(…and make sure you've got good plug wires)

Great thread, thanks Dan, a long read.

Planning on picking up blue streak cap and rotor for it, and put the one that came with it as a spare in the trunk.

Plug Wires are good. 8mm MSD Street Fires, that I custom fit in a few years ago. Boots all checked and dielectric grease reapplied to the boots when I put it together.

 

[slantsixdan]

Planning on picking up blue streak cap and rotor for it,

Blue Streak stuff may or may not be as good as it was, so tread carefully. The BS rotor has a short contact, which is the opposite of what you want. See if NAPA will still sell you an Echlin MO-3000 (tho I wouldn't use an Echlin cap…but Standard-Blue Streak bought Echlin awhile back, so the crummy build quality of the Echlin caps might have spread to the Standard-Blue Streak ones).

You might want to eyeball caps from United, Liland Global, and Wells.

 

[Bewy]

Scientist,
I suggest you read below & note the underlined words such as 'maimum', 'saturated', 'full'.

 

[RustyRatRod]

Neato, but spare some love (and time, and attention/work) to your cap and rotor especially if you're going to run big-*** plug gaps. Detailed info in this long (but worthwhile) thread. Written for 6-cylinder applications, but applies even more so to 8s because of the narrower/tighter spacing between adjacent contacts in the cap. Even factory HEI setups without the coil-in-cap arrangement use a big-diameter cap to space out the contacts.

(…and make sure you've got good plug wires)

"big ***". That covers a lot of territory.

 

[RustyRatRod]

Scientist,
I suggest you read below & note the underlined words such as 'maimum', 'saturated', 'full'.

View attachment 1716480410

Trust me when I say Matt doesn't need you to school him on electronics.

 

[Bewy]

Well it sounds like he needs somebody.....

 

[slantsixdan]

"big ***". That covers a lot of territory.

In context: bigger than factory 0.035" if we're being strict, 0.040" if we're being permissive.

 

[slantsixdan]

That thing where you get confirmation, without having to smell the particulars, that you made the right choice of mouseclicks awhile back