how to know if i need a ballast resistor

Just did a re wire on my boat. I am about to break in the cam. one thing I was thinking is if I need a ballast resistor or not. Its a chev 350 carbed. with points. I have the convertion kit but they suggest to wait till after break in to install .. All the diagrams I have looked at dont show a ballast resistor

Re: how to know if i need a ballast resistor

wrong pic hang on. ok i cant find a pic of it.
how do you know if you need a ballast resistor.
I have a one wire alternator

Re: how to know if i need a ballast resistor

The alternator shouldnt have anything to do with it. You will have to check volts to the points, it should be no more then 9 volts. If your getting more you will need one. Some boats have resistor wire, and some a ballast, also some coils have a bulit in resistor. I may be a bit off, but think Im right, its been years since I missed with points.

Re: how to know if i need a ballast resistor

Why would the breaking in of the engine have anything to do with having to have an antiquated points system or not?

Re: how to know if i need a ballast resistor

candrive55 said:

wrong pic hang on. ok i cant find a pic of it.
how do you know if you need a ballast resistor.
I have a one wire alternator

Click to expand...

What's the model number of your engine?

Basically, if you have points, you either need a ballast resistor, a resistor wire, or a coil with an internal resistor. It prevents the typical 14.4 volts from burning up the points in a short time.

Re: how to know if i need a ballast resistor

In the absence of hard data on your coil, I suggest the following: Install one. The only penalty is weaker than normal spark. If the rest of the system is wired correctly for use of a resistor, you will receive full battery voltage to the coil during cranking. When the engine starts, the voltage to the coil will reduce. If the system is not wired correctly, you'll miss the full voltage during cranking, but it will probably still start fine, if all else is well. Note that you can do your own temporary bypass by using a good cliplead between the two terminals of the resistor, shorting past it. Remove the cliplead when the engine starts.

The penalty for not using a resistor when the system is designed for one is eventual coil burnout, and/or points failure.

A resistor is cheap insurance until the details are verified.

Also note that the above posters comments about internal resistor coils and resistor wires are also quite valid, and the "voltage at points" test should give you an answer, when tested by parking the engine with the points open. Testing while operating will not give you an answer you can use for diagnosis, unless you have an oscilloscope.

Neither the internal resistor coil or resistor wire will be harmed by having an extra resistor in-circuit temporarily.

Waiting until you're sure of what you have is, of course, the safest course of action...

Chip

Re: how to know if i need a ballast resistor

Hi again. I am pretty sure the coil says internal resistor on it . But will double check today. for the model number of engine.
Its a sbc 350 carbed heres a pic

so how and were do i use my multi meter to do the tests you speak of
Thanks

Re: how to know if i need a ballast resistor

found the part number to the coil its ignition coil 27270... not for use with external resistor. am I in the clear

Re: how to know if i need a ballast resistor

Follow the coil specs.

Re: how to know if i need a ballast resistor

Why don't you just put the conversion kit in? Your engine doesn't care if the spark is from electronic conversion or points during break in.

Re: how to know if i need a ballast resistor

I would love to put the conversion kit in. Heres the info on why not.. from the conversion company ""To get the ignition running initially, only these wires should be attached to the coil's + and - terminals:

A. +12 volts from the ignition switch to the coil's + terminal


B. Red Hot-Spark wire to the coil's + terminal


C. Black Hot-Spark wire to the coil's - terminal. DO NOT connect any +12-volt wire to the coil's - terminal. Connect only the black Hot-Spark ignition wire to the coil's - terminal.


D. The automatic choke and fuel shut-off valve may also need to be attached to the coil's + terminal.


E. Generally, only the black Hot-Spark wire is attached to the coil's - terminal. If a tachometer wire is usually attached to the coil's - terminal, don't attach it until the timing has been set and engine is running properly. No other wires should be connected to the coil's + and - terminals at this time."""

This worried me because I am about to break in the cam. I emailed them and they said . To be safe wait till after break in.

full info on kit http://www.hot-spark.com/Installing-Hot-Spark-Mallory.htm

...also where would i find the specs for the coil....thanks guys

Re: how to know if i need a ballast resistor

Personally, putting anything on your engine with the word Mallory attached to it is a bad thing.

I emailed them and they said . To be safe wait till after break in.

Click to expand...

That, is scary. Make me wonder why they would say something like that.

Re: how to know if i need a ballast resistor

Thats what the motor came with. Cant find much info. Going to run it with out a ballast resistor. unless i hear differant here. yes or no

Re: how to know if i need a ballast resistor

You will probably only get between 2000 and 3000 miles before you need new points without a resistor.

Re: how to know if i need a ballast resistor

ok thank you i will run a ballast resistor. But can you tell me why the coil says on it " not for use with external resistor"

Re: how to know if i need a ballast resistor

I have no clue what coil you have, who made it or anything else. So how can I say what it means.
Get the coil for your engine and ignition system from the OEM, then you know if you have the right thing or not.

Re: how to know if i need a ballast resistor

part number to the coil its ignition coil 27270... not for use with external resistor.

Re: how to know if i need a ballast resistor

candrive55 said:

so how and were do i use my multi meter to do the tests you speak of
Thanks

Click to expand...

The hot-spark istructions spell it out pretty well for you:

Do this to the coil disconnected from everything:
Coil: Coil MUST have 1.5 Ohms or more primary resistance. To measure primary resistance: Label and remove all wires to coil ( + or - ). Using a common digital multimeter in the 200 Ω mode, cross the red and black leads of the Ohmmeter. Allow a few seconds for the reading to settle and write down the reading.

Still in the 200 Ohm mode, measure between coil?s + and - terminals. Allow a few seconds for the reading to settle, until it stabilizes. Subtract the previous reading, taken with the leads crossed, to compensate for multimeter?s inherent resistance. Do not use a low-resistance coil, such as the MSD or Accel coil; they don?t have enough primary resistance for this application. Using a coil with too little primary resistance can cause the ignition module to overheat and misfire until it cools down again or fail, voiding the warranty.

Check the voltage reading at the coil's + terminal, engine running, at 2,500+ RPM. If the voltage measures more than +14.2 volts, you'll need to replace the voltage regulator, install a coil with 3 Ohms or more internal primary resistance or install a 1.4 Ohm external ballast resistor between the ignition switch and the coil's + terminal.

For best performance, the coil should also have a 7,000 Ohms or more secondary resistance (measured from coil?s + or ? terminal to center high tension terminal, in the 20K Ω mode of the Ohmmeter).


Do this with the motor off everything connected:
Test Battery Voltage to Coil: With ignition switch ON, engine not running, check voltage at coil?s + terminal. The voltmeter should read somewhere around +11 to +13 volts. If voltage is too low or there?s no reading, the battery?s terminals or ground connection may be corroded and need cleaning or the battery may need charging. Some vehicles have a resistor wire running from the ignition switch to the coil?s + terminal. If this resistor wire drops the voltage below 9 volts or so, you may need to run a non-resistor wire from the ignition switch to the coil?s + terminal or run a +12V wire directly from the ignition switch to the red Hot-Spark ignition wire. Make sure that the ignition switch terminal to which you connect this wire has power only when the ignition switch is in the ON position. Or, you can, for temporary testing purposes only, run a wire directly from the battery's + terminal to the coil's + terminal, the Hot Spark ignition's red wire to the coil's + terminal and the black Hot-Spark wire to the coil's - terminal. Do not leave the wire from the battery connected to the coil's + terminal for more than a minute or so without the engine running.

Double check when you have it running:
Test Maximum Charging System Voltage: If the charging system voltage, measured at the coil?s positive terminal, is more than 14.2 volts at 2,500+ RPM, the voltage regulator likely needs replacing. Too much voltage can damage the ignition module and other electronic components.


source:

full info on kit http://www.hot-spark.com/Installing-...rk-Mallory.htm

Click to expand...