Resistor vs Non Resistor Distributor Cap

[2manycars]

I'm doing a bit of work on my 64 Caddy. I want to install a repro Delco Remy distributor cap thats available through the Chevy suppliers. They come in both resistor and non resistor types. Anyone know the difference and which is best to use on this car?

[Mike Josephic CLC #3877]

As far as I know, for your year car there is no resistor
in the distributor cap.  That's a feature that some
newer vehicles had, but not in 1960.  If I'm wrong I'm
sure that somebody will quickly correct me!

The resistors are in the plug wires.

Mike

[bcroe]

The resistors are in the plug wires.   Mike.

Yes.  The resistor wires or plugs were used to reduce radio interference.
Bruce Roe

[Cadman-iac]

That's correct,  the resistance is provided by the spark plugs and wires, not the distributor cap.
AC plug numbers use the letter "R" to designate a resistance plug, like a R43TS, or whatever number your vehicle needs. I just recall the number for my truck as I just changed them.
As for the wires, the old steel core wires had no resistance in them other than what would naturally occur in the steel itself, and you would get a lot of noise in your radio from them.
The newer silicon wires with the carbon core do have some resistance to them to help keep ignition noise from your radio.
As for the cap, the one offered today is basically identical to what yours had when new. There's just one thing to look for in the cap and that's the material the terminals are made of. You can get it with aluminum or brass. I would opt for the brass one as it's a better conductor.

I hope this is what you wanted to know .

Rick

[spolij]

Rick      I'd guess it wouldn't hurt engine performance weather you have resistors or not.

[2manycars]

That's correct,  the resistance is provided by the spark plugs and wires, not the distributor cap.
AC plug numbers use the letter "R" to designate a resistance plug, like a R43TS, or whatever number your vehicle needs. I just recall the number for my truck as I just changed them.
As for the wires, the old steel core wires had no resistance in them other than what would naturally occur in the steel itself, and you would get a lot of noise in your radio from them.
The newer silicon wires with the carbon core do have some resistance to them to help keep ignition noise from your radio.
As for the cap, the one offered today is basically identical to what yours had when new. There's just one thing to look for in the cap and that's the material the terminals are made of. You can get it with aluminum or brass. I would opt for the brass one as it's a better conductor.

I hope this is what you wanted to know .

Rick

Thank you all. I suspected the non resistor type would be the right one. I recently had all of my HVAC system components rehabbed. Meantime, the engine and trans leak oil like mad, so I am pulling them, replacing the timing chain set, and resealing both engine and trans. Then I will repaint them and reinstall. I am freshening up everything under the hood that I can right now, so I'm putting all back as close to original as new appearance as I can in a short time. That's why the original style cap, dated wires, numbered hoses and belts, etc. It was really beginning to deteriorate under hood, even though the car runs and drives very well - aside from the rather large leaks.

[Jon S]

That's correct,  the resistance is provided by the spark plugs and wires, not the distributor cap.
AC plug numbers use the letter "R" to designate a resistance plug, like a R43TS, or whatever number your vehicle needs. I just recall the number for my truck as I just changed them.
As for the wires, the old steel core wires had no resistance in them other than what would naturally occur in the steel itself, and you would get a lot of noise in your radio from them.
The newer silicon wires with the carbon core do have some resistance to them to help keep ignition noise from your radio.
As for the cap, the one offered today is basically identical to what yours had when new. There's just one thing to look for in the cap and that's the material the terminals are made of. You can get it with aluminum or brass. I would opt for the brass one as it's a better conductor.

I hope this is what you wanted to know .

Rick

No true. Packard wires had TVRS indicating carbon coating and resistor capability.  TVRS stands for TV and Radio Supression.

Update:  just took a picture of my wires:

[Cadman-iac]

No true. Packard wires had TVRS indicating carbon coating and resistor capability.  TVRS stands for TV and Radio Supression.

Update:  just took a picture of my wires:

Thank you for the correction Jon, I didn't know that.  What year did those become available,  do you know? Just curious now. I'm gonna start looking at all my old wires now.

Rick

[David Greenburg]

If from a Chevy supplier, the resistor cap may be for a Corvette.  Not my area of expertise or interest, but I do know some 60’s Corvettes had a bunch of shielding and suppression for the ignition.

[Cadman-iac]

If from a Chevy supplier, the resistor cap may be for a Corvette.  Not my area of expertise or interest, but I do know some 60’s Corvettes had a bunch of shielding and suppression for the ignition.

As I recall,  the shielding was just a metal shroud, (in pieces), that covered the distributor and wires in an effort to limit the effects on the radio from ignition noise.

[Mike Josephic CLC #3877]

As I recall,  the shielding was just a metal shroud, (in pieces), that covered the distributor and wires in an effort to limit the effects on the radio from ignition noise.

That's correct -- with a fiberglass body, there was no other
way to isolate the ignition system from producing radio static. 
At the NCRS shows, I would see the judges actually use tools
to remove this shielding to check for "correct" distributor
components.  Crazy, but true.

Mike

[Caddieman53]

My 53 calls for a resistor type rotor under the cap. You can see a small resistor soldered in on top of it.

[Cadman-iac]

My 53 calls for a resistor type rotor under the cap. You can see a small resistor soldered in on top of it.

I hadn't heard of that before. It would be interesting to see if you ever get a chance to take a picture of it.
I enjoy looking at how people engineered things when faced with a problem, because different people approach things in different ways.
That's one way I would never have thought of to control ignition noise.
I would think the heat added to the rotation would melt the solder and fling the resistor right off the rotor.

[bcroe]

I have seen rotors with a resistor.  The resistance and some shielding
helps enough that now you hear all the other cars that have no spark
noise suppression.  To completely contain the noise on my 62 (for HAM
radio application) I bought an aircraft style shielding system that was
near waterproof.  It did also avoid that missing sometimes after a big
puddle.  But it could not deal with the voltages of my HEI.  Bruce  Roe

[Jon S]

My 53 calls for a resistor type rotor under the cap. You can see a small resistor soldered in on top of it.

That is correct and not modified.

[Cadman-iac]

That is correct and not modified.

I believe that. What I meant was it's interesting to see how "people", ie: the engineers solved issues like this. It's always a learning experience for me and I really enjoy looking at all the different ways to fix the same problem. People can be so ingenious, and I try to think about the process and how they arrived at the solution. It makes you wonder about all the things they might have tried that didn't work.
I like to take things apart just to see how it works, and I really enjoy making something work again. Especially something electrical, like the radios from my '56 with the Wonderbar feature.

Rick

[Jon S]

  I believe that. What I meant was it's interesting to see how "people", ie: the engineers solved issues like this. It's always a learning experience for me and I really enjoy looking at all the different ways to fix the same problem. People can be so ingenious, and I try to think about the process and how they arrived at the solution. It makes you wonder about all the things they might have tried that didn't work.
I like to take things apart just to see how it works, and I really enjoy making something work again. Especially something electrical, like the radios from my '56 with the Wonderbar feature.

Rick

Me too and making things not available like this topper:

[Cadman-iac]

Me too and making things not available like this topper:

Jon, I'm curious about those pictures you posted.  Is that cover for hiding your non-original battery,  or have I missed your meaning?

[Jon S]

Exactly. It’s a home made battery topper to replicate the original GM battery

[2manycars]

I ended up purchasing the reproduction Delco-Remy "Patent Pending" cap and an upgaded rotor from Rick's Camaros, it being the correct cap for my 67 Camaro. If I like this cap I'll get another one later on for the Camaro.

I also got the dated wire set from McVey plus a carb kit, and numbered hoses and some other stuff from Caddy Daddy. Timing set (Cloyes) from Rockauto. I really need to get that engine out ASAP and seal that puppy back up. It should look nice once I get everything spruced up again.