Packard Forum Index » Post-War (1946-54)

I recall an experience I would like to share with the site.

One hot summer day in the mid-1950s we had a tourist, driving a Studebaker V-8, come into the garage complaining of a poor running and low performance. This car was from another state and low altitude (mid-west as I recall). Santa Fe is 7,200 feet above sea level. This altitude often caught those not familiar with the power loss at high elevation unawares of the power drop. The power loss is about 20% from what is available at sea level. Taking all of this into account the Studebaker still ran badly. I believe this was a 6-volt Studebaker, as it was before they went to 12-volts.

We found some interesting items in the ignition system. The rotor was a resistance type; it had a resistor in the high tension lead from the coil to the distributor; and had resistor spark plugs. This strangled ignition system, and when coupled with high altitude sickness just about kept the car from making any good forward motion.

We replaced the rotor with a non-resistor type; replaced the high tension lead with one without a resistor; and, I believe, retained the resistor spark plugs (cleaned and re-gaped). The performance improvement was remarkable.

This particular customer experience stands out in my mind as what can happen when too much resistance is used in an ignition system.

(o{}o)

Interesting Studebaker story. The in-line resistor in the coil wire was common if a car was not factory-equipped with a radio and thus radio resistance wires.

However I pose this: Packard Senior V8's had a resistor in the rotor, resistance plug wires and commonly resistor plugs when tuned up. Those ignition systems and similar Delco systems in GM cars did not suffer ignition deficiencies whether 6V or 12V

12V systemns are not ":hotter" any more than 12V headlights are any brighter. A 12V Delco system employs a ballast resistor which drops the running voltage to about 7, just like a nominally 6V system. The big advantage of a 12V system with high compresion engines is that it gives more power to spin the starter plus there is a relay to put the full 12V to the coil for starting.

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CORRECTION
HAS BEEN BROUGHT TO MY ATTENTION THAT PERHAPS V8'S DID NOT HAVE RADIO RESISTANCE IGN WIRES ORIGINALLY. MY STATEMETNSTILL HOLDS AS MOST HAD WIRES REPLACED DURING THEIR LIFETIMES WITH RESISTANCE WIRES AND THEY RUN JUST FINE

Fred, Your points in your posting are well taken.

My point was not that it was a Studebaker story, but a story involving a Studebaker. It could have been any marque.

Your point about 6-volt systems not being "hotter" than 12-volt systems is a good one, that is until the introduction of high energy ignition systems much later. It could have been a 6-volt or 12-volt system on that car. It would not have mattered.

My point was that the engine's performance was greatly impaired due to the excessive resistance in the ignition system, and when some of those items were removed the performance enhancement was most notable.

I question your statement that Packard and other systems routinely had a resistor rotor, TVRS spark plug wires and resistor spark plugs, and functioned properly. Only one resistor in the system would be sufficient to reduce TV and radio interference.

Do you know when TVRS (televison radio resistance suppression) high tension wires were made mandatory? I think it was around 1955.

(o{}o)

REsistor spark PLUGS prior to the late 1960's at the earliest????? Maybe police or taxi or military vehicles. I doubt that resistor plugs existed at all prior to 1965 for anything. At least not in the US.

Keith, thanks for this info. Any guess about when TVRS wires came to be used?

(o{}o)

I don't know about the TVRS plug wires. Probabaly late 40's to early 50's. I'm fairly sure that they were widely used in production by 1958 at the latest. The R plugs was an early 'customer proving ground' used in production just for a few years just prior to e-ignition. I know of no e-igntion that does NOT use R plugs. e-ignition got started about 1973. As far as i know there was no e-ignition in any US production car prior to late 1960's at the earliest.

All the OE plug wires that I've examined on V8 Packards had a solid metal conductor. Initially, the silver color of the wire made me think it was (stainless) steel, but I've heard that it is actually tin-plated copper.

I put a set of modern suppressor-type wires on my '56 Carib shortly after I acquired it - just to get by. I can't offer any performance conclusions, either way, but the wire is so flimsy that it droops and interferes with the throttle linkage - even with the late design cable supports. They'll be going in the trash.

As for resistor type plugs, the 55-56 parts book offers no such applications in the Electrical section (Gr. 4.1105)). While the Utility section (Gr. 50.675) of that same book does show a few resistor types, you have to go back to the 48-54 parts book to find any actual application listings for those P/Ns. However, the are listings are rather non-specifics - that is nothing but year/series. Yet, none of those resistor plugs are shown in the annual "Mechanical Specifications" for any of the 49-54 vehicles.

My guess is that resistor plugs were initially offered, back then, for radio noise suppression in cars that did not have a carbon rod in the rotor. Resistor plugs only really became necessary, along with suppressor type wires, with the advent of transistorized ignition systems in the 1960s - to protect from the effect of RFI and EMI. Same for computerized engine management control system, in later years.

Over the years, I'm sure many Packards were fitted with whatever parts the typical "grease monkey" could find for a "tune-up", but I prefer OE.

My memory says 56 Packards did not use resistor plugs. I don't remember resistor wiring either. They did have a resistor rotor.
http://www.gsparkplug.com/shop/champion-n18.html

TO JW

Thanks. JW , I referred to it a the Studebaker story as a point of reference, did not consider your story to be Studebaker exclusive, if anything it was Delco related as only Delco used a resistor rotor. Sometimes when you replace a part and it fixs the car is has nothing to do with the part, could be jostling a loose wire etc.

The purpose of resistor items in the ign is to modulate the fluctuations in current, the amount of "loss" is insignificant, a resistor plug has 5 ohms of resistance surely not enough to cause a car to run poorly. The replacement of resistor wires with solid core may make a huge diference, but only if the resistor wires are dried out and shorting or the center filament is burned due to incorrect installation of the ends. Putting new resistor wires would make the same inmporovement.

One day someone walked under a ladder and then had bad luck,they attributed it to walking under the ladder. Actually if they ahd read their horoscope they would have stayed in bed.

Actually yoiu could have fixed the Studebaker with Kanter Auto Products Universal Clothespins. Put on fuel lines, any wire or antenna (Get REAL Flying Saucer broadcasts!!)

TO PACKARD V8

Again I am fascinated at your information and its source.
In particular to resitor plugs being used in service in a "customer proving ground" just prior to intro of e-ignition in the late 60's. I went to our spark plug literature and found a 1958 catalog " AUTOLITE RESISTOR SPARK PLUGS". Such information is but a few clicks away on ebay.

I will search to see how early a catalog with resistor plugs I can find. I do not like to this kind of research, but those of us who are trying to find solutions can get misled with incorrect information.

"EVERYONE IS ENTITLED TO THEIR OWN OPINION, BUT NOT THERE OWN FACTS"