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Tue Oct 15, 2024 11:06 am

Hello,

I have been unable to locate an answer to my question.
I have searched The Samba and Rob and Dave's site.

What is the resistance for the rotor on a DVDA distributor and
What is the resistance for the rotor on a Pertronics distributor?

Tue Oct 15, 2024 11:28 am

The short answer is it depends. If you have a multimeter you can test it yourself. Some people use rotors with resistance and others have zero resistance.

What do you need this information for?

Tue Oct 15, 2024 12:12 pm

Thanks for your reply, I do have a meter and was troubleshooting an idling issue.
I have several rotors; 2 ohms, 1k ohms, 4.95k ohms. The cap and original rotor
looked a little dark in the center. I replaced with the cap and rotor from a new
unused Pertronics distributor. My original distributor is a DVDA on a stock 1600.
I will order replacements. I read somewhere that water cooled VW rotor
resistance is 1k ohms. You rebuild distributors, are air cooled rotors resistance~5k ohms?

Tue Oct 15, 2024 12:19 pm

Most stock distributors had a 5K-ohm resister cast into them.
I've seen one burn out and arc, and cause poor high speed running.
I don't know what the Pertronix units like.

Tue Oct 15, 2024 12:23 pm

The resistance can be all over the place. It depends on the manufacturer and part number.

Fri Oct 25, 2024 9:52 pm

I am not sure exactly what is available, but replacing the resistance rotor with a none resistance rotor and then using a resistance coil wire would be one way to go.

heimlich will surely know more about what is available than I.

Tue Nov 05, 2024 8:46 pm

Typically, a type 1 engine with points gets the 5kohm rotor. (Most work out to about 4.9k anyway…) They typically have a narrower metal tip than the 1k ohm rotors I see on the Vanagon and 79 CA bay with electronic ignition and special coil.

I’ve never tried a zero ohm rotor, and I wouldn’t bother with a radio. Most ignition system resistance is to stop buzzing and other electronic interference, like a skittish tachometer. If your spark plug wires and/or coil wires have over 1k of resistance, it shouldn’t matter what rotor you use. If you’re using spark plug wires with no resistance, go for the 5k rotor. I’ve always felt the DVDA’s wider timing map appreciates the wider rotor tip, but that’s just speculation.

Some spark plugs have resistance built in as well. (NGK plugs have R’s at the end of their part numbers, for example.) The point is, you want SOME resistance, but not every part of your ignition system needs to be high resistance.

Pertronix manuals will list their respective resistance expectations.

Robbie