Jack, we've been looking for you!

[Iron Duke NCRS #22045]

Be sure you give us your take on ballast resistors. The thread started with Andy Anderson's "What does the ballast resistor do?" on June 1 at 10:55PM. It was kind of a long thread that went on for a couple of days, so maybe you should start a new one.

Duke

[Jack H.]

Re: Jack, we've been looking for you!

Been busier than a one-armed paper hanger, guys! Know you're in good hands with pros like Terry, Joe, Et. Al. Also, schedule isn't going to lighten up in the near future, but I DID manage to pencil whip registration forms for the Bowling Green National along with booking a berth on the Road Tour!

Ballast resistor is simple! It's switched out of circuit during engine cranking so you get full battery power applied to starter motor AND coil/points for best electrical start profile. Once, ignition switch is returned to RUN position, ballast resistor sits in series with ignition coil primary windings to 'gobble' up (reduce) electrical energy flowing through points and coil primary.

This makes points last longer and helps reduce the 'nasty' -- propensity for points to 'weld' shut when ignition switch is in the ON position, engine is not running, and at last shut down the points happened to come to rest in the close position. This is a 'malady' situation for judging where there are rather lengthy periods where we need to have electrical power active without the engine running....

TI equipped cars and later (post mid-year) designs saved $$$ by implementing the ballast resistor in the form of a 'distributed' component. Instead of a dedicated ceramic housing with wire-wound heart bolted to the firewall, they used controlled wire gauge runs inside the engine electrical harness to simulate the effects of a modest series resistor in line with points and coil primary. Eliminated a discrete component and worked quite nicely, thank you.

Original ballast resistors essentially came in two styles. The high performance ballast was a rather low resistance value (around 0.4 ohms) and was used on high end engines where high rev profile demanded lower 'ballast' (energy discard) on the coil primary. These are identified by a characteristic 'black dot' on the mounting band, AND if you snake an inspector's mirror around the back side of the resistor's ceramic case you'll find a small ceramic cover mounted over the resistor's wire windings (presumedly to thwart accidental metallic contact of the wire winding to the mounting band -- short circuit the ignition primary!).

The low performance ballast was identified by a blue band across the upper mounting lug (blue ink crossing the white ceramic). Typical ballast resistance was 1.8 ohms for this assy.

Some judges look for originality by inspecting the metal mounting band for the script Delco Remy logo that was embossed. Also, some judges look for originality in terms of finding a modest 'squared tab' end adjacent to the resistor's mounting hole in the band. In my personal opinion, I don't believe the squared tab end = correct/original....

Why? Well, if you pull the original D-R drawing for this part and inspect closely you'll see it was a PURCHASED ITEM! Despite the fact known originals have the D-R scrip logo embossed, these were apparently bought rather than made by GM. In my humble opinion, GM almost NEVER granted sole source status to a purchased part (if vendor goes on strike, GM shuts down!). Plus, I've walked many a scrap yard and pulled 'untouched' original ballast resistors off cars (some high performance, most low performance) and have seen quite a few with the D-R script logo deboss AND without the tiny squared off end.

In my opinion there were multiple vendors then and it's possible for a correct original ballast to NOT have the squared end. But, that's just one man's opinion. Currently, what comes from Chevy and/or parts catalog houses does NOT have the tab on the end of the mounting tab....

Last, in the pre-57 era the ceramic was quite different (geometry and form) as well as the mounting band itself. So, the part changed over time in terms of assy cosmetics and the early ballasts are visibly different from today's service replacements.

[Fred Oliva]

Re: Jack, we've been looking for you!

Well said Jack. I particularly agree with your opinion about the squared off end tab (may or may not be there).

Fred O

[Roberto L.]

Welcome amigo!

Welcome back to the board. We were missing you Master.

Roberto, NCRS #30019, RMC

[Dale Pearman]

Ballast Resistors Revisited

First of all, has anyone tried to purchase a C1 ballast resistor lately? They have been discontinued for quite some time and none of the parts houses have them any more. (the 1119 short #). There were several versions of ballast resistors in the years 1956 to 1962. A 1956 passenger car has 1.6 or so ohms resistance, no dot, a straight porcelin platform under the terminals and a "tab" on the mounting band. No dot or stripe. The dot-stripe thing started in C3 production. 1956 to 1959 resistors for Corvettes were 0.3 ohms (at 75 degrees), no dot, a tab on the band and a straight platform under the terminals. Late 1959 through 1962 had a tab, were 0.3 ohms and were notched under the terminals with NO dot. All these puppies were trade-marked Delco. An identical to 1956 passenger car resistor existed without the tab Also 0.3 ohms. The radius of the top of the mounting band varied and was not very pronounced in a 1.7 ohm non-Corvette version. Again, all Delcos.

The ballast resistor is a current regulating device that adjusts it's resistance as a function of radiated heat and average current, (power dissipated) which is rpm dependent. It's a very crude but effective analog computer.

Rev. Varooom!

[Dale Pearman]

Re: Jack, we've been looking for you!

If you are judging 1958 through 1962 Corvettes the tab should be there.

Dale Pearman

[Dale Pearman]

Re: Welcome amigo!

I think Roberto should write all his posts in Spanish or at least provide the correct Spanish translation for his English writing, or vice versa! Probably vice versa would be best. We can all afford to brush up on our lingustic skills since the USA will soon be bilingual!

Puede ecribir mas facilemente en la lingua de Espania Roberto?

Su amigo,

Senior Varooom!

[Jerry Clark]

Get Back Jack..

Ya just can't be that busy ???

Jer

[Jack H.]

Disagree

I'm not judging in this area, Dale, but my personal take is I see WAY TOO MUCH that's based on small sample extrapolation of known original cars in our club lacking the grunt work of primary investigation/documentation.... This is one of those things.

I said:

(1) I have the GM part drawing. (2) It calls out the part as a PURCHASED item. (3) It defines a Purchasing vendor file drawing. (4) My background as an engineer from Detroit says SELDOM would a company

the size of GM justify a SOLE SOURCE status for a purchased part

especially when it could threaten corporate production shutdown. (5) Seldom do multiple vendors supply parts with IDENTICAL tooling.... (6) I've seen 'untouched' ballast resistors on scrap yard cars from that

era lacking the tooling tab. (7) Without further source investigation/documentation I would be the LAST

judge to deduct and deprive the owner the benefit of the doubt based on

this feature alone of a fully functional part....

I would suggest that those judges who believe I'm wrong, go get the file wrapper on the purchased part vendor drawing, read the ECR history, document the vendor(s) that were qualified to provide the part over time, pull their part drawings THEN research the then current mini/max criteria in place at GM as to what vendor(s) supplied what final assy plant(s) to justify their deduction positions.... Yes, just because, say 12, vendors were qualified on a given GM part number does NOT mean more than one or more delivered their version of the part to St. Louis for Corvette usage. This is the Catch-22 that some reproduction parts suppliers use to 'convince' us their version of a given part is 'correct'. But, it's also an argument loaded with falicy as GM often used 'perferred' sources to supply particular final assy locations to minimize freight-in expense.

What I will/do say is, "I know I don't know" an until there's further due diligence/proof, I won't deduct on my NCRS Judging Field for this subtle construction difference....