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MSD Coil Readings #2775888
05/18/20 06:09 PM
05/18/20 06:09 PM
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Indiana
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YO7_A66 Offline OP
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I am testing my MSD 8222 (Vibration) coil and I found that it should read on the Primary side .7Ohms (- to + post) and on the Secondary side is should be 4.5kOhms (- to center post).

Mine shows .6-.7 Ohms on the Primary side but the Secondary shows 153.6-154.2kOhms. Do I have a messed up Secondary on this coil?

""The MSD Ignition Blaster High Vibrations Coil (Part# 8222) is not vehicle specific. The specifications are turns ratio: 100:1, primary resistance: 0.7 OHMs, secondary resistance: 4.5K OHMs, inductance: 8 mH, maximum voltage: 45,000 Volts""

Thanks
Dave


1970 YO7 A66 [Canadian Export] F8 Challenger
340 (Currently in shop for stroker assy.)
Re: MSD Coil Readings [Re: YO7_A66] #2775951
05/18/20 09:02 PM
05/18/20 09:02 PM
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Fulton County, PA
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CMcAllister Offline
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34 times normal resistance? Yes, that is a problem.


If the results don't match the theory, change the theory.
Re: MSD Coil Readings [Re: CMcAllister] #2775960
05/18/20 09:12 PM
05/18/20 09:12 PM
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YO7_A66 Offline OP
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Thanks.
I just wanted to make sure before I bought another.


1970 YO7 A66 [Canadian Export] F8 Challenger
340 (Currently in shop for stroker assy.)
Re: MSD Coil Readings [Re: YO7_A66] #2775971
05/18/20 09:23 PM
05/18/20 09:23 PM
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Morrow, OH
markz528 Offline
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Check your meter and test method. I would expect the normal failure to be shorted turns so a lower reading. In my opinion it would not be a normal failure for resistance to increase.


67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......
Re: MSD Coil Readings [Re: markz528] #2775983
05/18/20 09:59 PM
05/18/20 09:59 PM
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YO7_A66 Offline OP
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I thought the number was way off so I measured the Primary side and the Secondary side at least four times each. I kept coming up with the same readings for both.

Thanks for the reply!!


1970 YO7 A66 [Canadian Export] F8 Challenger
340 (Currently in shop for stroker assy.)
Re: MSD Coil Readings [Re: YO7_A66] #2775987
05/18/20 10:09 PM
05/18/20 10:09 PM
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Ontario, Canada
RealWing Offline
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I just measured my 8222 coil and measure 5000 ohms. A very high reading like you got seems very odd. Could your reading be a meter problem?? calibration?
Jim

Last edited by RealWing; 05/18/20 10:11 PM.

1970 Superbird 440-6bbl, auto
1969 Barracuda 340-4bbl, FB Formula S auto
1969 Barracuda 6.1 L Hemi, 5 speed, Convertible
2022 Can Am Spyder RTL
Re: MSD Coil Readings [Re: YO7_A66] #2776001
05/18/20 10:58 PM
05/18/20 10:58 PM
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Bend,OR USA
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Cab_Burge Offline
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Are you using a digital meter or a older analog mechanical meter?
did you verify the zero reading with both leads hook to each other? If not do that first to make sure the meter is accurate, I keep some known value wire wound resistors in stock to test my cheap hand held digital meters. Tools and electrical meters do go bad and test leads go bad also, trust but verify up scope


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: MSD Coil Readings [Re: Cab_Burge] #2776062
05/19/20 08:25 AM
05/19/20 08:25 AM
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I asked one of our electrical techs at work this morning to test this coil with his meter. His readings on the Primary side were .6-.7ohms, and the Secondary side were 154-155kohms. Both meters are older digital units and both meters started out with the L and were both zero’d out.

Thanks again!

Re: MSD Coil Readings [Re: YO7_A66] #2776071
05/19/20 09:14 AM
05/19/20 09:14 AM
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Originally Posted by YO7_A66
I am testing my MSD 8222 (Vibration) coil and I found that it should read on the Primary side .7Ohms (- to + post) and on the Secondary side is should be 4.5kOhms (- to center post).

Mine shows 6-7 Ohms on the Primary side but the Secondary shows 153.6-154.2kOhms. Do I have a messed up Secondary on this coil?

""The MSD Ignition Blaster High Vibrations Coil (Part# 8222) is not vehicle specific. The specifications are turns ratio: 100:1, primary resistance: 0.7 OHMs, secondary resistance: 4.5K OHMs, inductance: 8 mH, maximum voltage: 45,000 Volts""

Thanks
Dave


Primary resistance....connect on + and - Secondary resistance connect on + and secondary tower

https://www.autoblog.com/2016/08/01/how-to-test-a-spark-plug-ignition-coil/

Re: MSD Coil Readings [Re: Dcuda69] #2776081
05/19/20 10:20 AM
05/19/20 10:20 AM
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YO7_A66 Offline OP
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I just went out and rechecked to find the “-“ to “SECONDARY” and the “+” to “SECONDARY” have the same reading of 154kohms.

Thank you.


1970 YO7 A66 [Canadian Export] F8 Challenger
340 (Currently in shop for stroker assy.)
Re: MSD Coil Readings [Re: YO7_A66] #2776188
05/19/20 04:46 PM
05/19/20 04:46 PM
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YO7_A66 Offline OP
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I picked up a new #8222 on my way home from work and it measured .7ohms on the Primary and 6.15kohms for the Secondary.

Thanks everyone!


1970 YO7 A66 [Canadian Export] F8 Challenger
340 (Currently in shop for stroker assy.)
Re: MSD Coil Readings [Re: YO7_A66] #2776216
05/19/20 05:56 PM
05/19/20 05:56 PM
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Morrow, OH
markz528 Offline
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Originally Posted by YO7_A66
I asked one of our electrical techs at work this morning to test this coil with his meter. His readings on the Primary side were .6-.7ohms, and the Secondary side were 154-155kohms. Both meters are older digital units and both meters started out with the L and were both zero’d out.

Thanks again!


Interesting. Not what I would have expected.


67 Coronet 500 9.610 @ 139.20 mph
67 Coronet 500 (street car) 14.82 @ 94 mph
69 GTX (clone) - build in progress......
Re: MSD Coil Readings [Re: YO7_A66] #2776418
05/20/20 11:46 AM
05/20/20 11:46 AM
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central il.
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second 70 Offline
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I had a new #8222 coil that in a short time got so hot you couldn't touch it but I never checked it. Sent it back to MSD to get it checked and they sent me a new one.

Re: MSD Coil Readings [Re: YO7_A66] #2776475
05/20/20 01:17 PM
05/20/20 01:17 PM
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USA
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I did some hands on measurements of Magnum V8 stock coils and aftermarket replacements some years ago. Here’s info from an old post:
.........

MSD Magnum Engine replacement coil

primary 1.2 ohms
secondary 13,700 ohms

For Info,
Here is what I measured on my 1995 model year stock Ram ignition coil this
afternoon:

Number on side of coil: 56027966

Primary Resistance 0.99 ohms
Primary Inductance 6.25 milliHenrys
Secondary Resistance 12,250 ohms
Secondary Inductance 41.9 Henrys

I put 6.3 volts of 60 cycle AC on the primary of the stock coil and got 453
volts AC on the secondary. The turns ratio of the stock coil might be about
453/6.3 = 72

Above measured with a seventeen year old BK Precision LCR Meter model number 875A and a Fluke 87.

The 1995 FS Manual says the coils are made either by Diamond or ToyoDenso.

For the Diamond the primary resistance is supposed to be between .97 and 1.18 ohms and the secondary 11,300 to 15,300 ohms.

For the Toyodenso the pri resis is supposed to be between 0.95 and 1.20 ohms and the secondary 11,300 to 13,300 ohms.
===================

Here's what the Accel catalog says about their Magnum Truck coil:

begin quote:

"DODGE "MAGNUM"
TRUCK / JEEP 1997-90 SUPER COIL

Engineered with optimized low resistance, high turns ratio windings around an
M36 high silicone magnetic steel C-core for higher energy and voltage outputs.
Results in quicker starts, improved idle quality, crisper throttle response
and more high RPM power. Compatible with late model MOPAR J-TEC computer
controlled ignition system and MOPAR high performance ignition computers.
Direct bolt-in, plug-in replacement. Can also work with an ACCEL, Mallory,
Crane, Holley or MSD capacitive discharge ignition systems. Special high
temperature epoxy resists shock and vibration, while increasing thermal
conductivity. Brass coil wire contact increases energy transfer efficiency and
resists corrosion better than aluminum. High dielectric strength "ACCEL
Yellow" over molded housing.

SPECIFICATIONS
Primary Resistance 1.0 Ohms
Secondary Resistance 12.7 k Ohms
Turns Ratio 76 : 1
Maximum Voltage 42,000 volts
Peak Increase in Energy vs. OE 34%
Peak Increase in Current vs. OE 17%
Peak Increase in Arc Duration vs. OE 23%
Peak Increase in Dwell vs. OE 36%

Dodge "Magnum" Truck / Jeep 1997-90 Super Coil . .140021"

end quote
==============

Here's what MSD says about the Blaster SS:

begin quote

Blaster SS Coil, PN 8207
The MSD line of Blaster Coils is known for great performance from the street
to the circle tracks. Following in that performance line, the new Blaster SS
Coil is ready to leave its mark.
The Blaster SS is an E-core style coil, which is a very efficient design when
it comes to producing high voltage and spark energy. The windings produce
300mA and can handle up to 48,000 volts when used with an MSD 6 Series
Ignition Control. The windings are held secure in a Dupont® RyniteT injection
molded shell and are then encased in an epoxy compound for protection against
vibration and water. The primary terminals are located at opposite ends of the
tall spark tower so there is no chance of arcing especially with the high
dielectric characteristics of the Rynite housing.
The Coil is compact enough to fit in tight areas and is supplied with
vibrations mounts.
Blaster SS Coil - PN 8207 CARB Approval Pending

BLASTER SS COIL SPECIFICATIONS
Primary Resistance: .355 ohms
Peak Current: 300mA
Secondary Resistance: 6,200 ohms
Spark Duration: 180uS
Maximum Voltage: 48,000 volts
Primary Inductance: 6milliHenrys
Turns Ratio: 70:1 Tested with an MSD 6AL
measured at plug gap.
==================

Bowling Ignition Circuit Simulator
Stock Ram Ign Coil part number 56027966

Input Parameters Are the Following:
Starting RPM = 500
Ending RPM = 5000
RPM Step = 250
Ignition Coil Primary Resistance (Ohms)= 1.0
Ignition Coil Primary Inductance (Millihenries) = 6.2
Dwell Angle (Crankshaft Degrees)= 30.0
Battery Voltage = 12.0
Ignition Coil Secondary Capacitance (Picofarads) = 100.0
Computation Results:
Engine Charge Time Primary Current Secondary Voltage Energy
RPM (millisec) (Amps) (Volts) (Joules)
---------------------------------------------------------------
500 10.0000 9.58 75714.7 0.287
750 6.6667 7.87 62219.0 0.194
1000 5.0000 6.61 52241.2 0.136
1250 4.0000 5.67 44845.0 0.101
1500 3.3333 4.96 39214.2 0.077
1750 2.8571 4.40 34808.1 0.061
2000 2.5000 3.96 31276.2 0.049
2250 2.2222 3.59 28386.1 0.040
2500 2.0000 3.29 25979.8 0.034
2750 1.8182 3.03 23946.3 0.029
3000 1.6667 2.81 22206.0 0.025
3250 1.5385 2.62 20700.1 0.021
3500 1.4286 2.45 19384.5 0.019
3750 1.3333 2.31 18225.5 0.017
4000 1.2500 2.18 17196.7 0.015
4250 1.1765 2.06 16277.5 0.013
4500 1.1111 1.95 15451.4 0.012
4750 1.0526 1.86 14704.8 0.011
5000 1.0000 1.77 14026.9 0.010
********************************************

CraneCams LX91 Ign Coil

Input Parameters Are the Following:
Starting RPM = 500
Ending RPM = 5000
RPM Step = 250
Ignition Coil Primary Resistance (Ohms)= 0.4
Ignition Coil Primary Inductance (Millihenries) = 5.3
Dwell Angle (Crankshaft Degrees)= 30.0
Battery Voltage = 12.0
Ignition Coil Secondary Capacitance (Picofarads) = 100.0
Computation Results:
Engine Charge Time Primary Current Secondary Voltage Energy
RPM (millisec) (Amps) (Volts) (Joules)
---------------------------------------------------------------
500 10.0000 15.64 113833.3 0.648
750 6.6667 11.73 85363.4 0.364
1000 5.0000 9.35 68047.3 0.232
1250 4.0000 7.76 56505.2 0.160
1500 3.3333 6.63 48286.3 0.117
1750 2.8571 5.79 42144.1 0.089
2000 2.5000 5.13 37383.0 0.070
2250 2.2222 4.61 33585.5 0.056
2500 2.0000 4.19 30486.8 0.046
2750 1.8182 3.83 27910.6 0.039
3000 1.6667 3.54 25735.2 0.033
3250 1.5385 3.28 23874.0 0.028
3500 1.4286 3.06 22263.6 0.025
3750 1.3333 2.86 20856.4 0.022
4000 1.2500 2.69 19616.5 0.019
4250 1.1765 2.54 18515.6 0.017
4500 1.1111 2.41 17531.6 0.015
4750 1.0526 2.29 16646.8 0.014
5000 1.0000 2.18 15847.1 0.013







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