COIL QUESTION

[CFD244]

Hi Folks

One of those things that I have never really thought about.........

The facts......SBM with oem electronic ignition using a Hi Rev 7000 ECU.
1.2 ohm accel coil (oem type) with .7 ohm ballast.

While running for a while, I touched the body of the coil while adjusting timing and it was so hot that I couldn't keep my hand on it. Is this normal, or is this thing running abnormally hot.

Thanks FABO

 

[RustyRatRod]

Hi Folks

One of those things that I have never really thought about.........

The facts......SBM with oem electronic ignition using a Hi Rev 7000 ECU.
1.2 ohm accel coil (oem type) with .7 ohm ballast.

While running for a while, I touched the body of the coil while adjusting timing and it was so hot that I couldn't keep my hand on it. Is this normal, or is this thing running abnormally hot.

Thanks FABO

You need somewhere in the neighborhood of a 1.5 to 1.7 resistor. .7 is too low. Especially when it gets hot.

 

[67Dart273]

I have never heard of a factory "spec" for coil temp. That is unfortunate. I have run into lots of them which run hot, but remember, the engine itself transfers a LOT of heat into the coil.

 

[Murray]

A coil should be very warm but not hot. Coils can fail due to overheating.

 

[Professor Fate]

Right from the specs: "Coil Primary resistance should be no lower than 1.4O."

 

[Bewy]

Assuming the 0.7 ohm res is what Accel specifies.......
Chrys used fixed dwell in their ECUs. To make the ECU 'high rpm' I would think they increased the dwell by using different components inside the ECU. I can see no other way of increasing the rpm limit when dwell is fixed, other than by extending dwell.

This means the coil is switched 'on' for longer periods of time at lower rpms....& gets hot. Also the reason that Chrys warns that some of the ECUs should not be used for long periods below a certain rpm. Fit a GM 4 pin HEI under the dist or on the side, keep the coil & res & both will run cooler. Or use an E core, no res, & get more spark power, 0.060" plug gaps.

 

[CFD244]

Assuming the 0.7 ohm res is what Accel specifies.......
Chrys used fixed dwell in their ECUs. To make the ECU 'high rpm' I would think they increased the dwell by using different components inside the ECU. I can see no other way of increasing the rpm limit when dwell is fixed, other than by extending dwell.

This means the coil is switched 'on' for longer periods of time at lower rpms....& gets hot. Also the reason that Chrys warns that some of the ECUs should not be used for long periods below a certain rpm. Fit a GM 4 pin HEI under the dist or on the side, keep the coil & res & both will run cooler. Or use an E core, no res, & get more spark power, 0.060" plug gaps.

I asked Rick Ehrenberg (sp?), the maker of the Hi Rev 7000, and he said that prolonged low RPM is not an issue with his box. But....He is selling, and the coil is really hot. Makes me wonder. Thanks for the suggestions.

 

[George Jets]

Lots of people here have not experienced this yet but, the mopar distributor to hei upgrade runs the 60,000 volt e-coil.

The E-Coil runs on straight 12 volts without a ballast resistor, and the E-Coil runs cool to the touch.

Quicker starts (along with the mini-starter upgrade) and the spark plugs burn clean.

The E-Coil is the magic behind it all, just need the mopar/hei to trigger it.


Spectra Premium C502, priced at $11.69

NGK 49034, priced at $27.79

Simple 2 terminal (+) & (-) electrical spade hookups.

OEM application for ordering parts:
1995 F-150 at RockAuto.

(you can't just run the e-coils with the standard mopar electronic ignitions)



* * * * *

 

[Professor Fate]

Lots of people here have not experienced this yet but, the mopar distributor to hei upgrade runs the 60,000 volt e-coil.

The E-Coil runs on straight 12 volts without a ballast resistor, and the E-Coil runs cool to the touch.

Quicker starts (along with the mini-starter upgrade) and the spark plugs burn clean.

The E-Coil is the magic behind it all, just need the mopar/hei to trigger it.


Spectra Premium C502, priced at $11.69

View attachment 1716373870


NGK 49034, priced at $27.79

View attachment 1716373872


Simple 2 terminal (+) & (-) electrical spade hookups.

OEM application for ordering parts:
1995 F-150 at RockAuto.


View attachment 1716373875



(you can't just run the e-coils with the standard mopar electronic ignitions)



* * * * *

Ah, but the HiRev claims to be compatible with E-coils...

 

[RustyRatRod]

Ah, but the HiRev claims to be compatible with E-coils...
View attachment 1716373883

And the Hi Rev is also made in USA.

 

[4spdragtop]

I was wrestling with chasing an electrical gremlin, altho it may not be directly related to your question.
It occurred to me that even minor "upgrades" we do can cause us issues.
For me(67 cuda) upgrade 1 was 70+ charging system.( so 71 Duster)
Upgrade 2 was elec ignition (started in 72/3??) (73 Duster)
So now walking into parts store working on our cuda just what the hell do you pick for a reference vehicle lol.
Rhetorical question.
But when u look at differences between 67, 71 and 73 there's a lot of variables.
So to get matched ballast and coil can be a frustrating exercise.
Good luck

 

[Professor Fate]

While by no means a comprehensive list, I keep a copy of this in a folder with my manuals. Sorry guys, it came from a Corvette site... but the resistor values are the key.

 

[junkyardhero]

ah yes... the usual: fit an HEI to solve a problem that doesn't exist.

with the correct and matched components there is *nothing* wrong with oem chrysler electronic. it's been run on millions of cars since jesus was a private and it works.

don't deviate from stock and you won't have no problems.

but yeah, let's all go reinvent the wheel.

 

[Bewy]

Sometimes the wheel can be made better.....HEI with an E core coil is a big improvement over the Chrys OEM. Why do you think HEI can run 0.080" plug gaps??

 

[junkyardhero]

Sometimes the wheel can be made better.....HEI with an E core coil is a big improvement over the Chrys OEM. Why do you think HEI can run 0.080" plug gaps??

i guess that would matter if i wanted to run 80 gaps on my plugs; but i don't, so it won't.

you should start a poll to see what gap everybody is running. i'd bet you dollars to donuts that a solid 90% are out there with 35~45. even with that precious HEI E core mumbo-jumbo.

 

[67Dart273]

ah yes... the usual: fit an HEI to solve a problem that doesn't exist.

with the correct and matched components there is *nothing* wrong with oem chrysler electronic. it's been run on millions of cars since jesus was a private and it works.

don't deviate from stock and you won't have no problems.

but yeah, let's all go reinvent the wheel.

I'm sorry. You are not correct. You would have been correct 20 or 30 years ago, but no more, why? Because you cannot waltz into a Mopar dealer and buy a genuine OEM just like it wuz in 1972, 1978, 1980 ECU. Most anything you buy will be aftermarket AND MADE IN CHINA

Even if you find NOS you are dealing with the possibility of deteriorated components, especially caps.

The same hold true for harnesses, namely, the connectors

 

[junkyardhero]

I'm sorry. You are not correct. You would have been correct 20 or 30 years ago, but no more, why? Because you cannot waltz into a Mopar dealer and buy a genuine OEM just like it wuz in 1972, 1978, 1980 ECU. Most anything you buy will be aftermarket AND MADE IN CHINA

Even if you find NOS you are dealing with the possibility of deteriorated components, especially caps.

The same hold true for harnesses, namely, the connectors

duly noted, i'll make it a point to replace and update the ignition systems in all my cars at the earliest possible convenience.

good thing all that HEI stuff at autozone and the dealer is made in USA

 

[George Jets]

Nothing Ventured, "Nothing" Gained

The old dog will not hunt...


* * * * *

 

[CFD244]

This is the coil I bought. Specs say universal with 1.4 ohm primary (I measured 1.2 with an accurate ohm meter). I bought it because the FSM listed 1.4 ohm for my vehicle. It is NOS from the 90's. Just reading the specs now, it says "points style". Would that make a difference If running an OEM electronic system?

 

[junkyardhero]

Nothing Ventured, "Nothing" Gained

The old dog will not hunt...


* * * * *

??

how am i to know what you're talking about without visual aids? maybe a defunct ebay ad would help as well.

 

[67Dart273]

duly noted, i'll make it a point to replace and update the ignition systems in all my cars at the earliest possible convenience.

good thing all that HEI stuff at autozone and the dealer is made in USA

Stop being so ******* sarcastic. The FACT is you and I mean YOU can not buy quality, OEM components to directly replace this stuff. Nor can you buy them in 3rd party.

It might just be, that even though the HEI stuff is ALSO import, that they are a little better simply because there were zillions of them produced.

 

[junkyardhero]

Stop being so ******* sarcastic. The FACT is you and I mean YOU can not buy quality, OEM components to directly replace this stuff. Nor can you buy them in 3rd party.

It might just be, that even though the HEI stuff is ALSO import, that they are a little better simply because there were zillions of them produced.

how's this, i'll stop being so ******* sarcastic when you fuckers stop acting like HEI is the second coming and be-all, end-all of what ever the **** this is. *waves raccoon paws around*

oem chryco electronic runs fine and is more than suitable for 99% of applications. and that's a FACT, jack.

 

[George Jets]

Re-read Post #8, then Post #14, then for sure Post #18, then onto 67Dart273's Post #21.

There are people and hobbyists from all over the world looking in here on FABO to learn.

They all want to learn ways to keep their cars running well, with the least amount of aggravation and expense. Availability of reliable parts around the world is a major part of it all too.



* * * * *

 

[junkyardhero]

Re-read Post #8, then Post #14, then for sure Post #18, then onto 67Dart273's Post #21.

There are people and hobbyists from all over the world looking in here on FABO to learn.

They all want to learn ways to keep their cars running well, with the least amount of aggravation and expense. Availability of reliable parts around the world is a major part of it all too.



* * * * *

oh, post #18?

sure thing Geronimo. i'll take that into account as soon as you stop doling out fundamentally bad advice and posting pictures that have no relevance to the discussion at hand. sounds like a fair trade, no?

if people are here to learn and all they're hearing is: "oem chrysler electronic is trash you need hei or you're destined to every sort of automotive malady on the face of the earth and in the known universe" then what service are we doing?

 

[RustyRatRod]

I'm sorry. You are not correct. You would have been correct 20 or 30 years ago, but no more, why? Because you cannot waltz into a Mopar dealer and buy a genuine OEM just like it wuz in 1972, 1978, 1980 ECU. Most anything you buy will be aftermarket AND MADE IN CHINA

Even if you find NOS you are dealing with the possibility of deteriorated components, especially caps.

The same hold true for harnesses, namely, the connectors

The Hi Rev 7500 boxes are made in USA. I don't know about the rest. But you're right in that most of what's left is chinesoated crap.