FBO's black HEI ignition box

-

moparlee

64 Valiant
Joined
Aug 18, 2004
Messages
1,558
Reaction score
101
Location
Joplin, Mo
How many bought it before the white one's came out?


310.JPG


309.JPG


311.JPG


307.JPG
 
Last edited:
The MSD HEI module # 83647 is better, switches 7.5 amp & has a rev limiter. Stock HEI modules switch about 5.5 amp.
 
Went through a bunch of modules at least three not counting the one in this picture in this....I'm actually going to let this one go with that new module I just got from you.
 
4 pin moduales? They usually last a long time. If you ever want to sell that black ecu box I would be interested. Easier to run/test module that way for rpm failure, my tetronix tester dos not do that.
 
Never even heard of these FBO boxes until this weekend, here. Thats one of the reasons I like this site. Even old coots like me can learn new stuff.

@Stephen Hotz will be making the ecu boxes with four pin moduales in them soon. Definitely needed.
I have been running an 8 pin GM module with the HEI8 coil off my OE style distributor for over 7 years.
Had to change it out once because of a top end miss.
I keep an extra one in my small tool box in the trunk.

The 8 pin module and HEI8 coils use weatherpak rubber sealed connectors unlike the Ford units that have exposed blade style terminals.
These 8 pin modules also have an ignition retard function that allowed the computer to deal with detonation via the module by applying 5v to one of the terminals in the unused socket, though I have never personally used that feature.
They also still fire with lower voltages than the 4 pin module. (Like a low battery scenario)
There are quite a few guys on this site running these that bought the ready to install kits from me, and I have also built these into the OE Mopar ignition boxes.

6F9A9058-48E6-4685-B253-8BFFBB0F1A57.jpeg


1D6B620C-88C5-4670-A331-3F2AA26B8ED8.jpeg
 
Last edited:
Is that on the black boxes or the new ones? I’ve got one of the new ones waiting to go in the swinger for a 383 that I plan to rev.

I‘m not sure which box he was talking about when he said it doesn’t retard with RPM.

Like I said, they ALL retard with RPM. How much and when it starts are variables.

Thats why you need to test for it.

I was there when Don started talking about building his own ignition boxes. I said it was a waste of time. I still say that.
 
Post #19. Higher amperage. One of the limitations of points ign & the Chrys ECU is the current a limited by the coil's primary resistance & the bal res connected in series with it.
The power [ energy ] in the spark is P= volts times amps, in simple terms. More power creates more heat & it is the heat that ignites the mixture [ not the voltage, it merely enables current flow ]. Lower resistance, more current. The high resistance of the Mopar coil [ about 1.5 ohms ] + the bal res limits current. The MSD 8207 coil has pri res of 0.35 ohms..& no bal res to further reduce current. Original OEM HEI coils had about 0.5-6 ohm.
So by increasing the primary current [ 7.5 amp ] , you increase the power of the spark. CD igns produce very high spark power, but about 1/10th the duration of inductive ign such as Chr & HEI.
GM specified 0.060 " plug gaps [ 0.080" for some engines ] & common sense tells you only a powerful ign system could fire a gap that large.
 
I'm not doubting you but would you elaborate a bit?
Is it more reliable? Cheaper? Easier to retrofit?
IMO, the only thing "better" about them is their availability. An original style Mopar electronic ignition is just as good with good parts. It's not hard to find good parts, either.
 
Kern,
The GM HEI has less external connections/connectors that can become loose connections or corrode. So from that perspective alone, it is more reliable.
A measure of the ignition's ability to fire a big plug gap is testament to the design & for inductive ign systems, the HEI wins hands down & is better than the Chrys system for reasons stated in post #22. I have run 0.125" plug gaps with HEI ign. Made no difference that I could feel, but certainly no misfires to 5500 rpm. An engine that I tune for drag racing in a 4000 lb car [ without driver ] has run 11.65/118 mph with a 3.31 axle & TQ carb. It has the MSD HEI module, 0.070" plug gap with Iridium plugs & runs to 6500 rpm.
HEI dist are now made for engines that previously were never equipped with HEI, Fords, Holden Chrys etc. Note that NOBODY is making Chrys dists for GM, Ford, etc. There must be a reason for that.....
Manufacturers do not spend money upgrading ign systems unless they have to & when they do they are looking for a more powerful spark, not less.....
One manufacturer { I believe it was Honda } built an engine in the 1980s that had a separate mini combustion chamber that created a 'fire' to ignite the main chamber. They obviously thought bigger is better....
 
Kern,
The GM HEI has less external connections/connectors that can become loose connections or corrode. So from that perspective alone, it is more reliable.
A measure of the ignition's ability to fire a big plug gap is testament to the design & for inductive ign systems, the HEI wins hands down & is better than the Chrys system for reasons stated in post #22. I have run 0.125" plug gaps with HEI ign. Made no difference that I could feel, but certainly no misfires to 5500 rpm. An engine that I tune for drag racing in a 4000 lb car [ without driver ] has run 11.65/118 mph with a 3.31 axle & TQ carb. It has the MSD HEI module, 0.070" plug gap with Iridium plugs & runs to 6500 rpm.
HEI dist are now made for engines that previously were never equipped with HEI, Fords, Holden Chrys etc. Note that NOBODY is making Chrys dists for GM, Ford, etc. There must be a reason for that.....
Manufacturers do not spend money upgrading ign systems unless they have to & when they do they are looking for a more powerful spark, not less.....
One manufacturer { I believe it was Honda } built an engine in the 1980s that had a separate mini combustion chamber that created a 'fire' to ignite the main chamber. They obviously thought bigger is better....


A big plug gap doesn’t make power. It’s hard on wires, caps rotors but it’s not a HP maker.

The HEI, like the GM advance mechanism is over rated.

The dude at DUI got his pee pee slapped for making the claim that his HEI ignition made more power than a mag.

Of course, that was a lie and that clown knew it. And BTW, a mag runs with gaps much tighter than a conventional ignition. No battery fired ignition will produce the power of a mag.

That right there shows the big gap myth.
 
-
Back
Top