What does the ballast resistor do?

[Andy Anderson]

HI, what does the ballast resistor to the coil do? What is the problems with running for a short time with out one? Just to start a new motor in the frame before puting the body back on. How can you test a old one to see if it is working? why do some people have there NCRS number on there posting? Thanks

[Ed Jennings]

Re: What does the ballast resistor do?

The ballast resistor cuts the voltage to the coil to something like 8 volts. This keeps the points from burning up. The "start" position on the ignition switch bypasses this resistor and sends full system voltage to the coil while starting. The wire from the "on" position on the switch goes through the resistor. You can test the resistor by temporarily jumpering it out. Running it this way for more than a few minutes is tough on the points. You can also test it with an ohmmeter. You should read somewhere around 1.4-1.6 ohms, depending one what you have. If you read infinate resistance, the resistor is bad.

[grr]

Re: What does the ballast resistor do?

Ed is right, If you have access to a digital volt ohm meter or multimeter use it. It's more accurate than a simpson.grr#33570

[Duke W.]

Re: What does the ballast resistor do?

If you have a solid axle Corvette or a C2 with a Special High Performance or Ruel Injection engine through '64 it should have the early ballast, which is only 0.3 ohm at room temperature, so it will likely read zero on a conventional analog VOM with nothing finer than a "times one" scale. This low resistance ballast increases primary ignition current, which increase ignition energy at the plug, but shortens point life considerably. If the ballast fails, it will probably fail open, which will disable the ignition system, but I don't think I've ever heard of one failing. They're very reliable. I'd suggest using one while your testing your engine. Without it you could burn up a set of points quite quickly and misdiagnose this as an internal engine problem.

As far as listing our NCRS "serial numbers", this is to let the unwary know our level of expertise. If a guy is below 10,000, he knows his stuff. If it's between 10.000 and 20.000 take it with a grain of salt. If it's over 20.000 don't even bother reading the post.:)

Duke

[Dale Pearman]

Membership # vs Expertise

If a member's membership number, which has absolutely no relationship to his credibility as a knowledgeable enthusiast, is REALLY low, WATCH OUT! Age brings with it a great deal of confusion. I'd like to see numbers remain confidential. There are many newbies out there who are quite knowledgable and many old timers who don't know squat! Also, disinformation is a game played by a few parts vendors in order to get into your wallet! The membership number is only an indication of when a person joined NCRS, which in my book, dosen't mean much as far a knowledge goes.

Don't get me started on this black-hat Master Judge 300 Club-500 Club thing! Pretty much the same thing. A Master Judge rating relates to how many times you've volunteered to judge NOT to whether or not you know what you're doing! I'm almost a 400 Club member, which means I've been to Judging School 400 times!

Varooom!

[Juliet P.]

NCRS numbers...

So Dale, Does that mean it took you 400 tries to pass judging school? Sounds like the diploma correspondence school option would have been a better deal for ya. LOL! Hee Hee hee....

Personally, I put my NCRS number up there to distinguish myself from all those other Juliet's who hang out on the forum with the rest of the lunatics. Plus it has the added benefit of keeping Eric from flogging me with his "Join the NCRS" posts. ~Juliet


Visit & Join the Online 1970 Corvette Registry!

[Richard T.]

Re: Membership # vs Expertise

I totally agree Dale , members numbers indicate nothing other than time in the organization and should not be posted either. Rich #2276

[Dale Pearman]

Re: NCR$ numbers...

What makes ya think I ever passed the NCR$ Judging school? Heck I'm still trying to learn!

Varooom! 9742157 (Tn. Dept. Corrections)

[Andy Anderson]

Re: Ed said, Duke said?

I have a 60, 270hp, Ed said that The ballast resistor cuts the voltage to the coil to something like 8 volts. Duke said the resistance ballast increases primary ignition current. ???? How about the coil, can it stand 12v for a longer time than just starting, said 10 min.?

[Dale Pearman]

Re: What does the ballast resistor REALLY do?

The ballast resistor can be viewed as an analog computer. It adjusts the average energy delivered to the coil by regulating the current through it. This is accomplished through internal resistance changes. The internal resistance depends on the temperature of the unit which in turn depends on the energy dissapated (power consumed) into the surounding air. The air ambient temperature affects this resistance. Also, since the waveform of the current through the resistor is virtually a sawtooth, the frequency of this sawtooth (rpm dependent) affects the average current (or power) delivered to the resistor. The idea is to provide the hottest possible spark, adjusted for rpm and ambient temperature, consistent with point longevity and coil primary protection. The secondary inductance of the coil, as well as it's primary inductance and secondary/primary resistances when superimposed with the effective impedance of the spark plug gap in an ionized oxidized cylinder gas atmosphere all combine with the coil capacitor to form a virtual resonant circuit after cylinder firing. The resistive partion of this circuit decays the oscillating envelope quickly enough to allow high rpm operation.

While judging a 62 at Steamboat Springs Colorado, I explained to the owner that the black dot on his ballast resistor didn't appear as factory original and in so doing I touched the dot with the middle finger of my right hand. The car had just been through an ops check and the resistor was QUITE hot. For the next few minutes I was dancing around with my middle finger extended upward while the owner assessed the extent of the burn. Onlookers concluded that I was expressing my opinions to the owner in typical Varoom fashion utilizing politically correct people skills! How easy it is to be misunderstood!

Varooom!

[Bill Baird]

Re: Ed said, Duke said?

I believe that Duke meant that the .3 ohm resistor increases primary ignition current compared to the 1.5 ohm resistor to which Ed was referring.

Bill Baird

[Jerry Clark #1]

Re: Membership # vs Expertise

On the seventh day I rested. On the eighth day I created the NCRS and it was good.

[Dave W]

Does this mean a TI ignition doesn't...

...need or use a ballast resister since there are no points? if so, is this the sole reason why TI supplies a hotter spark? Pardon my green'ness.

[Dale Pearman]

Re: Membership # vs Expertise

What happened? What makes you think it was good? Do you have a part # for good?

Varoom?

[Dale Pearman]

Re: Does this mean a TI ignition doesn't...

Means the TI has it's own electronic control module that adjusts current by using a power transistor. Much more sophisticated than a ballast resistor. Best deal ever is a HEI system. REAL long inductive spark (lasts comparatively forever) thereby increasing the probability of a hydrocarbon molecule drifting into the path of the spark and causing ignition. MSD capacitor discharge gives a succession of real short sparks to accomplish same thing. I run all my mouse motors on a TI type distributor (rotating pointless magnetic pick up) and ship the signal into a walmart HEI module mounted on a heat sink. I use a modular HEI coil off an S-10 pick up. Ole Red (pick up) has gone about 600,000 miles with this system and I have never had a problem. Starts right up in winter also.

Varooom!