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Why do I need coil condenser?

Posted: Sun May 14, 2017 10:43 am
by GasDaddy140
Hi! With points and condenser, why condenser on coil? If needed , + or - connection?
Thanks!

Re: Why do I need coil condenser?

Posted: Sun May 14, 2017 11:08 am
by miniman82
It's basically a capacitive filter, keeps noise down and also stores a little energy to help fire the coil. I don't think you'll hurt anything by having another, but it's not required.

Re: Why do I need coil condenser?

Posted: Sun May 14, 2017 11:37 am
by 64powerglide
+++++++++++ :tu:

Re: Why do I need coil condenser?

Posted: Sun May 14, 2017 11:48 am
by bbodie52
The condenser acts as dampener for the electrical current that crosses the points, preventing current from arcing (jumping) across the open gap in the breaker points and ensuring that the circuit is broken cleanly. By providing a path for absorbing the voltage, it helps to prolong the operational life of the points. (The ballast resistor wire in the primary circuit also contributes to the purpose, by reducing the primary voltage to the minimum that is acceptable with a running engine).

The condenser (capacitor) on the coil is there to reduce the static (popping sound) on the radio. Some generators and alternators have them too, with a similar purpose. Charging system radio interference sounds like a "whining" sound, that varies in pitch with engine speed. Some radio systems are not sensitive to this interference. If you omit the condenser on the ignition coil or on the generator and you hear no radio interference, you don't really need the radio noise suppression condensers. The one inside the distributor is always needed to extend the life of the ignition points.


Re: Why do I need coil condenser?

Posted: Sun May 14, 2017 12:24 pm
by 66vairguy
In the old "AM radio" days a condenser (capacitor) at the "+" coil terminal was required to prevent ignition noise on the radio while listening to an AM station. The condenser was NOT installed if you did not order a radio. It provides very little help to the coil function. In conjunction with the resistive ballast wire it does keep voltage fluctuations from gettting back into the main power system - not really much of a concern in the mid 60's as there were no computerized items in a car.

The condenser (capacitor) at the points has a primary purpose of reducing points arcing, any voltage spike control was a secondary function. All Corvairs had the points condenser.

Also the spark plug wires were resistance type to keep minimize radio interference electrical energy - in fact Petronix and other electronic ignition systems warn against using non resistance, or metal core, ignition wires because the energy they radiate is enough to interfere with the electronic modules.

Re: Why do I need coil condenser?

Posted: Sun May 14, 2017 3:54 pm
by GasDaddy140
Thanks for all of your help! Great little ignition video.
I thought that I was on-my-way for start-up, set-up...and then my replacement (supposedly tested) 12 row oil cooler failed during the drill motor oil test. I have another oil slick on my work table. Is it just my bad luck or what? I've got new seals. Both oil coolers leaked from the lower left corner. There was no trail of oil from the fitting or seals. It's back to the oil cooler problem :think:

Re: Why do I need coil condenser?

Posted: Sun May 14, 2017 4:13 pm
by bbodie52
There are a number of Corvair oil coolers listed on eBay...

ebay :link: http://www.ebay.com/sch/i.html?_from=R4 ... r&_sacat=0

You could also check with Clark's Corvair Parts, the Corvair Ranch :link: http://www.corvairranch.com/, etc.

Re: Why do I need coil condenser?

Posted: Sun May 14, 2017 4:55 pm
by GasDaddy140
Hi Brad, eBay's where I bought the 2nd one. I'll wait until the seller responds to an email that I sent about the cooler leaking.

Re: Why do I need coil condenser?

Posted: Sun May 14, 2017 5:54 pm
by cnicol
As Brad and Vairman66 noted, the sole function of the capacitor on the side of the ignition is to suppress AM radio noise from the ignition system. Unless you are an AM radio aficionado, it is not required. The coil's radio capacitor installs to the coil's "+" terminal.

Below is an image of the low-frequency mayhem (voltage fluctuation) present at the coil "+" terminal. In addition to this low frequency stuff, there's also radio-frequency "noise" and that's what the coil condensor absorbs. Note the spikes right in the middle of the image; that's probably where the RF stuff is happening. Not exactly smooth DC voltage that's for sure.

Re: Why do I need coil condenser?

Posted: Mon May 15, 2017 6:32 pm
by GasDaddy140
Wow. Pretty cool stuff Cnicol. A little heavy for me, but I liked it.

I want my Corvair Corsa running! I've got the sickness bad now.

Are you running a small reverse rotation Buick v-8 in your hot rod Corvair?

Re: Why do I need coil condenser?

Posted: Mon May 15, 2017 7:36 pm
by cnicol
GasDaddy140 wrote: "Are you running a small reverse rotation Buick v-8 in your hot rod Corvair?"
Craig replies: Yup! Bored and sleeved to accept 265 Chevy pistons so now it's 255 cubic inches. Goes like stink!