Resolved. - Dead in the field. Ignition module ?

[Adrian Worman]

Personally I think the issue is more to do with modern production techniques.

I think you are spot on there Daveman

[Dave999]

i agree

the article makes good reading but again is peppered with summit racing/american advertising-isms

im surprised the line

really builds horsepower wasn't rolled out
or some comment about exhaust note an aggresive rumble mybe


Any gains in torque and BHP have to be down to how marginal the previous ignition was....
1) not very sicentific test, i could prove how good points are if my previous igntion was smoldering charcoal
2) do you want to buy a product where the main drive in the advertising is slagging off the oposition

all new digital technology.......is a bit of an open ended statement

if it isn't programmable like the some of the 7 and later MSDs and their clones i have to ask what the digital part is for....?
you impelement digital circuitry to do the maths, to make complex decisions and there aren't any to be made here

you don't need a digital circuit to read the analogue pulse wave from the reluctor pickup
and digital electronics don't like HT voltages...anyone sane keeps digital stuff well away from HT and high magnetic fields...digital stuff goes under the dash safe with your mobile phone....not bolted up next to the hot engine and magnetic mayhem

my guess is its a simple counter chip to implement the rev limiter and drive the LEDS

which leaves the igntion side of things again dependent on that big fat 1960s transistor sitting on the heatsink on the front....unless thats a dummy to make it look orginal....

my guess is that it probably uses this

a motorola MC334

http://html.alldatasheet.com/html-pdf/3 ... 3334P.html

in which case

its much like an HEI with a rev limiter same control chip

It has taken years but it is now my belief that unless you are buying a programmable ECU

nobody is doing anything new

mybe i'm just too cynical

Again with this one the box the heatsink and that transistor in a metal can probably cost more than the rest of the stuff inside.

they miss out 1 very important bit of information

its a 1 coil none wasted spark igntion
what is the current handling capability of the box
and what is the ideal coil primary resistance....these ultimately dictate how hot the lot gets and its RPM range

high current builds magentic flux in the coil faster which means smaller dwell can be used which means it can sustain the same power spark to higher in the rev range, which is hard work on engines with 8 or more cylinders....



sorry just my view

and i'm stricktly spend money on the cheaper thing first if it fails go the next step
not buy the expensive thing first and discover later that the $17 jobby does 98% of the job you just paid $300 for

Dave

[Dave-R]

Mopar Muscle used to have a really bad reputation of doing "tests" that show the equipment (made by the companies sponsoring the magazine) out perform the parts made by their rivals (that do not sponsor the magazine).

I would expect things have not changed much since then. I am more inclined to trust tests carried out by Mopar Action. They are usually good at honestly comparing apples with apples.

[RobTwin]

the ballast would be needed with points becasue the curent flow through the low resistance MSD blaster would weld them together....

no need to worry when the HEI is you switch in the system. it can't weld together and has its own current limiting to stop it turning into a minature volcano

leave the ballast where it is for the standard look

and use some piggy back lucas spades to loop a wire from one end to the other....put back the orginal wires on the piggy back connectors

Dave

As our ballast resistor and its wiring is already/still there, would it be possible to keep it in the circuit with the GM HEI & Blaster coil, or would it be detrimental to either the coil or the ign module?

Just thinking it would be easier for us to leave the wiring as-is, and incorporate the ballast resistor, rather than trying to bypass it and hide the link

[Dave-R]

You can use the ballast resistor if you don't mind a weak spark and a decrease in power and fuel economy.

[mopar_mark]

You can use the ballast resistor if you don't mind a weak spark and a decrease in power and fuel economy.

Sounds like a good plan

[Dave-R]

You can use the ballast resistor if you don't mind a weak spark and a decrease in power and fuel economy.

Sounds like a good plan

I have a way with words don't i?

[RobTwin]

Point taken

[Charger]

so, just to confirm i am understanding this …

i have Mopar Performance Electronic Ignition kit fitted (orange box) with MSD Blaster 2 coil

i also have a ballast resistor, came with the kit, which is odd if you don’t need one for a non-points ignition … ??

when running i’ve got 13.8v at the battery and 6.6v at the coil, and the ballast resistor is getting Bananarama hot!!

so, i can bypass the ballast resistor and run 12v to the coil, right??

[Adrian Worman]

The ballast is a supposed to get very hot, it's doing it's job .
The resistor you have is maybe a 0.5ohm unit? Will be printed on it hopefully, but I'd expect a little more than 6 v at the coil, 8-9 would be better but I bet you have less than 12v at the ign side of the ballast? Usual Mopar connector block bollax
An MSD blaster coil shouldn't fry without the ballast tho, that was all the resistor was protecting

[RobTwin]

....and dont forget a standard, oil-filled coil, should be fitted vertically, or upright, or it too will get hot as all the internals will not be cooled by the oil.

That's why we've got the Blaster coil #8222 which is gel-filled, as it can be mounted horizontally on the inlet as the originals were.

From MSD -
"It is recommended to mount the PN 8202 and 8223 coils in an upright position. The High Vibration Coil, PN 8222, can be mounted in any position due to its epoxy potting compound."

[Dave-R]

Yes as Adrian says the resistor normally gets very hot. That is why it is mounted in ceramic.
It is there to limit voltage to the stock coil. It has nothing to do with being a points or electronic distributor.

[Dave999]

so, just to confirm i am understanding this …

i have Mopar Performance Electronic Ignition kit fitted (orange box) with MSD Blaster 2 coil

i also have a ballast resistor, came with the kit, which is odd if you don’t need one for a non-points ignition … ??

when running i’ve got 13.8v at the battery and 6.6v at the coil, and the ballast resistor is getting Bananarama hot!!

so, i can bypass the ballast resistor and run 12v to the coil, right??

you need one for an igntion that is designed as system to run at 3 amps or below current flow

if you miss it out of your oarnge box set up, the coil will allow much more than 3 amps to flow due to its low primary resistance and that current flow will burn out the big transistor mounted in your orange box....

in the olden days..

all cars had 6 volt lectrics
when the starter motor was running the voltage dropped so much that there wasn't enough for the igntion
so they made the igntion work excellently at that low voltage instead,
meansing when the starter motor stopped the full six volts was too much
so they included a balast resistor which they switched into circuit when the starter motor stopped and out of circuit when the starter motor was running
this is a voltage eater

it eats the excess voltage seen when the starter motor load is no longer there...i.e when the car is running...

it was vital with 6 volt electrics

loose 2 volts to the starter and you have lost 33% of your voltage
loose 2-3 on a 12 volt system and you have lost about 17% much less


in later years with the advent of 12 volt electrics they did the same thing

made the igntion work at 8-9volts and used a balast resistor to eat those extra 3 volts that became avilable once the car started...

this meant that

1) the igntion worked very well during starting
2) they could spend less money and save more space and weight by putting a battery in the car that was JUST good enough. to get a battery that had enough OOOMph not to allow volatge drop under starting would have meant a huge diesel truck battery.


igntions fell into 2 main groups in the early 70s
all were 12 volt

those with a balast
those without

the balast resistor igntions were designed to have coils that ran best at 8 volts.

Voltage is the push factor in electrcials so you built a coil that when it had 8 volts pushing current throuigh it that current was approx. 3 amps
it was limited to 3 amps in essence by the balast resistor because current flow in a circuit is dictated by the resistance of the circuit as a whole and is there fore the same anywhere you measure it if the components are in series, and in this case they are.

3 amps becasue in most cases it had to be carried by points and they tended to get damaged by more...

non balast igntions

tended to be used on smaller lighter cars with smaller lighter engines with smaller starter motors and the same old lead acid 6 7 or 8 cell battery

voltage drop on running the starter was much less than on a hulking v8 or v6 due to the smallness factor less torque necessary to start and higher RPM turn over during start meanst less power used by starter motor and less volatge drop

and balast resistors due to the temp they get to do have a habit of burning out

save on component count
simplify
less points of failure

build an igntion without a balast...

this igntion has a 12 volt coil, a coil that has resistance built into it that limits the current flow to approx 3 amps

thus the points survived


Mopar boxes
used on hulking great v8s

why change to a 12 volt igntion system when the 8 volt balast one you have used since the 1940s is good

hence

mopar box igntion

uses a coil which likes 8 volts , 4 volts are used up by the balast reistor when the car is running
and the igntion still only sees 8 0r 9 volts when the starter is running becasue it caused voltage drop and the balast resistor is switched out of circuit during starting

the coil current flow was limited to about 3 amps..which was good beacuase anythinng more would have caused thermal breakdown of the transistor that was used instead of points.


so why get rid of the balast resistor
they fail
its an extra component
batteries are much better
coils exist that can flow up to 7 amps
swicthes i.e electronic controls, exist that dont burn out if more than 3 amps flow

GM and HEI.

GM had a problem acheiving emissions standards in the early 70s
they chose catalytic converters as the key to achive
their catalytic converters worked well but only if they were never ever ever exposed to unburnt fuel....they were regularly with old points 8 volt igntions....when they were they stopped working and got very very very hot which cause dthem to fall to bits


they key to sorting this

an igntion with the clout of a mig welder

they found a chip that could switch up to 5 amps reliably without buring out

they built a coil that used a design that was centred around ideas used in eletcricity substations and household electrical goods

the coil had a laminated core, special low resistance wire encased in plastic which concentrated the magnetic field much better than an iron rod solenoid in an oil bath (like all other automotive coils)

but it was an open structure, no can around it to stop magnetism flying all over the place

by its nature this coil could be made very low resistance
i.e at 12 volts it might flow 7 + amps....but becasue it was so good on the magnetic side of things that 7 amp flow was for a very short period of time becasue the coil filled up with magnetic flux really quick which by its nature reduces the current flow to near zero once full

MINT said GM

we have a coil that gets to max power in a much shorter time than any before
we do this by running double the current into it
but for shorter time so our switch (chip) will survive
this means dwell can be reduced across the whole rev range
and it means we can maintain good spark power up to about 7K rpm

Our expensive catalytic converter will no longer fall to bits and cause warranty cliams

HEI
High Energey igntion

much better coil
slightly better switch
some control circuitry that can alter the dwell based on coil reistance
the coil will produce decent spark with anywere from 2 amps to 7 amps fllowing so even if the voltage drops during starting to 6 volts we still get approx 3 amps through the coil so we can jetsion the balast as well...

our only problem is the massive clods of magnetic field thrown out by our coil that causes the magnetic pickup in our distributor to misfire.....
and the horrendouse cross talk from the rotor if the plug gaps are too big

hence

HEI distibutor is double the diamater of any before it
it has massive plastic shielded rotor (to avoid cross talk and phasing problems)
and the coil was either mounted a long way away on a special coil mount that dictated its orientation

or in a very specific orientation on the cap in relation to the pickup in the dizzy so that false triggers were avoided.


The chip is encased in a 4 5 or 7 pin module
the 4 pin module is easy to use on an old car

it takes the ziggy zaggy signal from the mopar or GM pickup
and uses it as a trigger to switch any 12 volt coil off and on
to get the benefits of HEI though

you need a decent 12 volt coil

MSD blaster 2 will do the job
or an orginal HEI coil
or indeed any laminated core plastic package coil off a mid 80s car which had just 1 coil

and you don't need your balast resistor because the whole system is designed to run at 12 -15 volts

Mopar and many of those based on mopar boxes are desigend to run at 8 volts with a balast and in essence more or less limit thesmleves to low current working


Dave

[latil]

Sometimes a magneto starts to appeal

[Adrian Worman]

Dave999 does some amazing answers