HEI guru questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hanssolo · 06-26-2003, 08:53 PM

2 questions about internal coil HEIs:

1. Whats the difference between the red and black and the red and yellow wire coils?

2. What are the symptoms of coil saturation?

Thanx

sbc350gearhead · 06-26-2003, 09:44 PM

Symptoms of coil saturation? Do you heak heat soak? Coil saturation time, is the time required for a coil to reach peak energy on the secondary side of the coil.

hanssolo · 06-26-2003, 10:37 PM

red and white-sorry my mistake. OK, thanx. I've been informed to use GM modules because some of the cheapos in the auto parts stores don't have what the GM modules have....variable dwell. Its in the module itself. This is'nt a computer thing. This is supposed to keep the coil from "over-saturating" at low rpms. Its supposed to help the coil last longer and give sharper performance. I guess over-saturation is what I would like to know about. Could it just be over heating? Check this site out.
http://www.thirdgen.org/newdesign/tech/hei.shtml

ps- gearhead350- you were right about the PCV valve thing.

sbc350gearhead · 06-26-2003, 10:59 PM

Over-Saturation probably refers to un-needed energy produced by the ignition circuit. This extra energy would shorten coil life due to the increase in heat. I honestly don't know of another downside, except that when amperage increases, resistance increases as well and therefore decreasing voltage. How much that would actually affect the very short path of the ignition circuit, I cannot say.

JimKshortstep4x4 · 06-27-2003, 07:26 AM

This was not one of your questions, but the pattern of a GM module is clearer on the distributor machine than after market
modules. After market modules will double flash when testing distributors. We only use GM modules in our HEI's because of the aftermarket modules inconsistant patterns of firing.

Jim

hanssolo · 06-27-2003, 09:46 AM

Jimk- thats good to know. But what do you mean by double-flash? Fire randomly a second time on the same cylinder? Thanx.

JimKshortstep4x4 · 06-27-2003, 11:05 AM

For the most part the aftermarket modules will fire in between
the normal flashes, so instead of (8) flashes per rev it will fire (16) per rev and they get worse as the rpm's increase. I am not absolutely sure of how it affects the running of the engine, but it can't be good.

Also, the clarity of the flash pattern is not good.

Jim

sbc350gearhead · 06-27-2003, 06:26 PM

Are the aftermarket modules in question the aftermarket hipo stuff (accel, msd,etc), or the autozone stock replacement stuff?

JimKshortstep4x4 · 06-27-2003, 08:05 PM

They are replacement modules. I have never tested an accel or other hi performance modules so I don't know how they would fire on a distributor tester.

Good question!

Jim

hanssolo · 06-27-2003, 10:57 PM

Jim- thanx for all the info. Good to know.

06-26-2003, 08:53 PM	#1
hanssolo Registered User Join Date: Sep 2001 Location: central Ill. USA Posts: 447	HEI guru questions 2 questions about internal coil HEIs: 1. Whats the difference between the red and black and the red and yellow wire coils? 2. What are the symptoms of coil saturation? Thanx __________________ 69 C10 longbed: 357c.i. /TH400/3.73s/AC/ beige primer/saving $ for paint ______________________________

06-26-2003, 09:44 PM	#2
sbc350gearhead Registered User Join Date: Mar 2003 Location: Columbus Ohio Posts: 1,413	Symptoms of coil saturation? Do you heak heat soak? Coil saturation time, is the time required for a coil to reach peak energy on the secondary side of the coil. Last edited by sbc350gearhead; 06-26-2003 at 10:55 PM.

06-26-2003, 10:37 PM	#3
hanssolo Registered User Join Date: Sep 2001 Location: central Ill. USA Posts: 447	red and white-sorry my mistake. OK, thanx. I've been informed to use GM modules because some of the cheapos in the auto parts stores don't have what the GM modules have....variable dwell. Its in the module itself. This is'nt a computer thing. This is supposed to keep the coil from "over-saturating" at low rpms. Its supposed to help the coil last longer and give sharper performance. I guess over-saturation is what I would like to know about. Could it just be over heating? Check this site out. http://www.thirdgen.org/newdesign/tech/hei.shtml ps- gearhead350- you were right about the PCV valve thing. __________________ 69 C10 longbed: 357c.i. /TH400/3.73s/AC/ beige primer/saving $ for paint ______________________________

06-27-2003, 09:46 AM	#6
hanssolo Registered User Join Date: Sep 2001 Location: central Ill. USA Posts: 447	Jimk- thats good to know. But what do you mean by double-flash? Fire randomly a second time on the same cylinder? Thanx. __________________ 69 C10 longbed: 357c.i. /TH400/3.73s/AC/ beige primer/saving $ for paint ______________________________

06-27-2003, 10:57 PM	#10
hanssolo Registered User Join Date: Sep 2001 Location: central Ill. USA Posts: 447	Jim- thanx for all the info. Good to know. __________________ 69 C10 longbed: 357c.i. /TH400/3.73s/AC/ beige primer/saving $ for paint ______________________________

06-26-2003, 10:59 PM	#4
sbc350gearhead Registered User Join Date: Mar 2003 Location: Columbus Ohio Posts: 1,413	Over-Saturation probably refers to un-needed energy produced by the ignition circuit. This extra energy would shorten coil life due to the increase in heat. I honestly don't know of another downside, except that when amperage increases, resistance increases as well and therefore decreasing voltage. How much that would actually affect the very short path of the ignition circuit, I cannot say.

06-27-2003, 07:26 AM	#5
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	This was not one of your questions, but the pattern of a GM module is clearer on the distributor machine than after market modules. After market modules will double flash when testing distributors. We only use GM modules in our HEI's because of the aftermarket modules inconsistant patterns of firing. Jim

06-27-2003, 11:05 AM	#7
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	For the most part the aftermarket modules will fire in between the normal flashes, so instead of (8) flashes per rev it will fire (16) per rev and they get worse as the rpm's increase. I am not absolutely sure of how it affects the running of the engine, but it can't be good. Also, the clarity of the flash pattern is not good. Jim

06-27-2003, 06:26 PM	#8
sbc350gearhead Registered User Join Date: Mar 2003 Location: Columbus Ohio Posts: 1,413	Are the aftermarket modules in question the aftermarket hipo stuff (accel, msd,etc), or the autozone stock replacement stuff?

06-27-2003, 08:05 PM	#9
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	They are replacement modules. I have never tested an accel or other hi performance modules so I don't know how they would fire on a distributor tester. Good question! Jim

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