Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: 2manycars on February 27, 2020, 04:43:44 PM

Title: Resistor vs Non Resistor Distributor Cap
Post by: 2manycars on February 27, 2020, 04:43:44 PM
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?
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Mike Josephic CLC #3877 on February 27, 2020, 05:23:08 PM
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
Title: Resistor vs Non Resistor Distributor Cap
Post by: bcroe on February 27, 2020, 09:39:28 PM
Quote from: Mike Josephic  CLC #3877

The resistors are in the plug wires.   Mike.

Yes.  The resistor wires or plugs were used to reduce radio interference.
Bruce Roe
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Cadman-iac on February 28, 2020, 12:30:12 AM
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
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: spolij on February 28, 2020, 10:29:43 AM
Rick      I'd guess it wouldn't hurt engine performance weather you have resistors or not.
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: 2manycars on February 29, 2020, 10:45:03 AM
Quote from: Cadman-iac on February 28, 2020, 12:30:12 AM
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.
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Jon S on February 29, 2020, 10:53:09 AM
Quote from: Cadman-iac on February 28, 2020, 12:30:12 AM
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:
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Cadman-iac on February 29, 2020, 04:54:33 PM
Quote from: Jon S on February 29, 2020, 10:53:09 AM
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
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: David Greenburg on February 29, 2020, 11:03:41 PM
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.
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Cadman-iac on March 01, 2020, 01:30:43 AM
Quote from: David Greenburg on February 29, 2020, 11:03:41 PM
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.
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Mike Josephic CLC #3877 on March 01, 2020, 02:49:32 AM
Quote from: Cadman-iac on March 01, 2020, 01:30:43 AM
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
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Caddieman53 on March 01, 2020, 07:43:58 AM
My 53 calls for a resistor type rotor under the cap. You can see a small resistor soldered in on top of it.
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Cadman-iac on March 01, 2020, 12:42:55 PM
Quote from: Caddieman53 on March 01, 2020, 07:43:58 AM
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.
Title: Resistor vs Non Resistor Distributor Cap
Post by: bcroe on March 01, 2020, 01:22:07 PM
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
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Jon S on March 01, 2020, 02:19:12 PM
Quote from: Caddieman53 on March 01, 2020, 07:43:58 AM
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.
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Cadman-iac on March 01, 2020, 02:43:13 PM
Quote from: Jon S on March 01, 2020, 02:19:12 PM
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
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Jon S on March 01, 2020, 03:37:48 PM
Quote from: Cadman-iac on March 01, 2020, 02:43:13 PM
  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:
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Cadman-iac on March 03, 2020, 07:50:07 PM
Quote from: Jon S on March 01, 2020, 03:37:48 PM
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?
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Jon S on March 04, 2020, 09:03:17 AM
Exactly. It’s a home made battery topper to replicate the original GM battery
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: 2manycars on March 04, 2020, 09:31:54 PM
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.
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: 2manycars on March 10, 2020, 09:22:53 PM
I received the cap and rotor today. The rotor is not a specific Delco repro. It is simply a 'High Performance' rotor as opposed to the standard one. The rotor feels substantial, like the original Delco Remy ones we used to be able to get in the 60s and 70s.

The cap is a really nice reproduction, right down to the box it came in. It has aluminum contacts. It has Delco-Remy Patent Pending cast into the top. The Chevy cap fits the Cadillac engine perfectly. It was nice of GM to share so many parts across the different car lines. It looks really nice. Some photos of it...

Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: 2manycars on March 10, 2020, 09:25:56 PM
By the way, does anyone have any idea what that finned gizmo is that's next to the fuel filter and appears to be in the PCV vacuum line?
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Cadman-iac on March 10, 2020, 10:16:13 PM
A picture of the piece you're asking about would help to identify it.

Nice cap and rotor though.
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: 2manycars on March 10, 2020, 10:26:57 PM
Quote from: Cadman-iac on March 10, 2020, 10:16:13 PM
A picture of the piece you're asking about would help to identify it.

Nice cap and rotor though.
It's visible in the 4th photo just to the rear of the glass bowl fuel filter, to the left of the distributor.
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Cadman-iac on March 10, 2020, 11:11:59 PM
I can't identify it with just this one picture. If you have a chance, maybe you can get a better picture that shows more of it, or better yet, if it's not too difficult to remove, take a picture that way.
Unless someone else can tell what it is, that would be the only way I could tell. There's just not enough of it showing that I could even make a good guess.
Since it's in the PCV hose, and I can see it has a clamp on at least one side, it shouldn't be too hard to remove.
Are there any other things connected to it? Another hose maybe?

  Rick
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: 2manycars on March 11, 2020, 11:23:13 PM
I took it off and searched on what was stamped into it. It's an air bleed device meant to reduce emissions. This one was just a straight vacuum leak, big time as it turns out. I have another thread with photos of it.
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: Cadman-iac on March 12, 2020, 12:17:41 AM
That sounds like one of many gizmos perpetrated on the motoring public back in the sixties, claiming to give you more miles per gallon. I would just eliminate it from your car.
I answered here as there was something wrong with the other thread.  It was expanded way too wide to see it for some reason.
Rick
Title: Re: Resistor vs Non Resistor Distributor Cap
Post by: bcroe on March 12, 2020, 04:41:06 PM
I reduce the resolution of pictures to around 150K.  A 5 meg picture does
not show any better here on the small screen, but avoids having to
constantly scroll back and forth to see a bit of it at a time.  Bruce Roe