Different 091 Coils

[Gene M.]

There are posts on the early 091 coils. Most seem to agree the numbers are on the bottom portion of the can. There still is debate on the type of top bak-o-lite configuration.

One has 4 small holes adjacent to the terminal posts and the other has raised lands adjacent to the center tower. My question is which is correct for '62 build?

Is it accepted that the 4 small hole version was the earliest version? And should all these applications have the 2 rectangle metal washers with a 90 degree bent tang to drop in the holes?

LOOKS AS IF NOBODY KNOWS.........?

[Timothy B.]

Re: Different 091 Coils

Gene,

Here is a picture of the 091 I have and I believe it's correct for 63 and probably 62. This coil has the four holes and the raised lands.

https://www.forums.ncrs.org/showthread.php?t=66826

[Gene M.]

Re: Different 091 Coils

Tim, thank you for reply. Yours is a combination of the two 091 coils I have. You have raised area and holes on the same unit. I have one with holes an no raised pads. And another with raised pads and no holes.

Is it possible all three styles were in production at the same time?

Now I am more confused than ever............

[William C.]

Re: Different 091 Coils

The progression was from 4 holes no pad to four holes with pads than pads only, at least based on originals I have dug up over the years. This was not only the '091, but Delco coils in general as the entire GM line changed over time. Not really possible to document the "all three at once" scenario, without all the Delco tooling documentation but unlikely as existing tools would have beed updated over time.

[Gene M.]

Re: Different 091 Coils

Bill,
I was totally ignorant of the 091 with holes and pads. Learn something everyday. But do you have any idea of time period or model years for the three styles of 091 usage on the Corvette assembly line build?

I assume there could have been overlap of three types as one was phased out and next phased in. True?

[Philip C.]

Re: Different 091 Coils

Bill,
I was totally ignorant of the 091 with holes and pads. Learn something everyday. But do you have any idea of time period or model years for the three styles of 091 usage on the Corvette assembly line build?

I assume there could have been overlap of three types as one was phased out and next phased in. True?

Hi Gene, Ken Kayser wrote a great article on coils in the restorer, Volume twenty one number three winter 1995 check it out. Phil 8063

[William C.]

Re: Different 091 Coils

Yes on the overlap, as tooling would have to be changed, BTW this was not only an '091 issue, but the entire Delco Remy coil line went thru this transition in the late 50's-early 60's. Boyont that observation I don't have enough date-definable examples to nail down the transition period. Perhaps someone would have the prints to at least nail down when the changes were initiated by engineering.

[Ken A.]

Re: Different 091 Coils

The 091 coil was a truck coil that began use on pass. cars with the change in ballast resistors, from what I have learned. The 091 was switched to the top of the coil, so the worker could see it and to facilitate the bracket clamp.

[Gene M.]

Re: Different 091 Coils

The 091 coil was a truck coil that began use on pass. cars with the change in ballast resistors, from what I have learned. The 091 was switched to the top of the coil, so the worker could see it and to facilitate the bracket clamp.

Ken, according to Ken Kayser article noted in above posting, the lowering of the embossed numbers on the can was done on March 8th 1967. Apparently they were high on the can to start with according to Kayser. Just the opposite of your explanation.

I think this is opposite the NCRS world thinking. Just because the drawing specifications were changed does not mean the tools were. But that would not explain the existence of coils per the earlier configurations with embossment toward lower end of can.

This whole coil thing is getting more involved than I ever thought it would.