18 replies to this topic

[kudu]

Hi Guys, just a simple question. Do I need my ballast resistor? I have upgraded the original Dizzy and Coil to a mallory twin point Unit and MSD Blaster 2 coil. So do i still need to use the resistor with these bits?

 

Cheers.

[antelopeslr5000]

Your points will have a longer life with the ballast resistor installed. Personally, I would have opted for a electronic distributor then you could have ditched the ballast resistor.

[TerrA LX]

^ One time agreed with the Queenslander.

 

Get a HEI dizzy and coil.

[76lxhatch]

A ballast resistor (or in factory Holdens, a resistance wire) is used for 9V coils, so you only _need_ one if you have a 9V coil (and the Blaster 2 is 12V). A 9V coil is used for the above reason, to increase the lifespan of the points - which is at odds with any upgrade where you want to increase spark energy.

[kudu]

A ballast resistor (or in factory Holdens, a resistance wire) is used for 9V coils, so you only _need_ one if you have a 9V coil (and the Blaster 2 is 12V). A 9V coil is used for the above reason, to increase the lifespan of the points - which is at odds with any upgrade where you want to increase spark energy.

 

Cheers for that. Its in the bin for the ugle white box then!  I only asked because I was reading in the forums somewhere that a resistor was used with 9V coil. I just wanted to be sure before removing it. Plus it seemed backwards to me buying a good coil like the MSD and then "Restricting" it.

[hanra]

Do you still have the resistance wire wired into your existing harness?

[kudu]

Do you still have the resistance wire wired into your existing harness?

 

No, I don't think so. All the wiring looks modern. There is just one wire going to the dizzy from the negative of the coil and a couple going to the positive via the resistor from the main wiring loom. Does that sound right?

[hanra]

The resitance wire is built into the loom.

[76lxhatch]

Why would it need a resistor, all that does is lower the voltage delivered...?

 

Its going to destroy the points in short order either way :-)

[V-SLR5000-P]

Resistor coils are sometimes are marked R in the part number (like Bosch) . A resistance coil sees 9 volts through the resistor during normal running while the resistor is bypassed during start up

cranking so that the coil temporarily gets 12 volts and gives a hotter spark. Running a resistor coil at full 12 volts  instead of 9 volts through the resistor for an extended period will kill it.

[76lxhatch]

I thought the Blaster 2 coil was high enough impedance that it didn't need a resistor, I must be confusing it with another one...

 

Like I said with a coil like that the points will burn up pretty quick regardless, but if you're right about it being a low impedance coil then the longevity of the coil itself is also a concern.

[hanra]

I've got a Blaster 2 sitting here. It's got a .8ohm primary winding resistance. That will burn through your points quick smart. I'm certain Pertronix make an electronic module to suit the Mallory twin point dizzys. But not sure if that coil will be suitable either. I'll check.

Edited by hanra, 13 March 2013 - 09:06 PM.

[hanra]

Yeah mate. Get yourself a Pertronix module. The 9ML-181 fits most Mallory dizzys and is an Ignitor II so it's suitable to use with your .8 ohm MSD Blaster II coil.

The Ignitor I can only be used with a minimum 1.6ohm coil.

http://www.pertronix...r2/default.aspx

Get onto Matt, he will sort you out. He is a good fella. Might take a week or two to get to you from the USA however.

http://bit.ly/WHc9eC

Edited by hanra, 13 March 2013 - 09:38 PM.

[kudu]

Although I suppose I could just leave my system as it is. The mallory and MSD coil have been in the car for approximately 10 years since I had the car and is working ok. It was just in the process of tidying up the engine bay that i wondered if I needed it that was all. And there is the old adage...if it aint broke don't fix it I suppose.

[hanra]

With that coil you have you will need to run a minimum .8ohm ballast resistor to give your points a chance. But for $100 why not go Pertronix anyways. You will never have to adjust points ever again. Especially a pair of them in a twin Mallory dizzy!!!!!

Edited by hanra, 14 March 2013 - 06:21 AM.

[kudu]

Good Point.

[hanra]

Get onto Matt, he is a good fella and will help you out!

 

http://bit.ly/WHc9eC