66 L79 air cleaner wing nut

[Robert P.]

Looking to purchase a correct wingnut for judging , at present have one from LIC which has a the right specs ( didn't pass judging) maybe the chrome finish is off a little and one other one with a cad plating type finish. Any help would be great
Bob Peckham

[Joe L.]

Re: 66 L79 air cleaner wing nut

Looking to purchase a correct wingnut for judging , at present have one from LIC which has a the right specs ( didn't pass judging) maybe the chrome finish is off a little and one other one with a cad plating type finish. Any help would be great
Bob Peckham

Bob------


Here is a guaranteed original GM #219281[not for sale]. So, this is what you're looking for:


DSCN4008.jpgDSCN4009.jpgDSCN4010.jpgDSCN4011.jpg

[Joe R.]

Re: 66 L79 air cleaner wing nut

Looking to purchase a correct wingnut for judging , at present have one from LIC which has a the right specs ( didn't pass judging) maybe the chrome finish is off a little and one other one with a cad plating type finish. Any help would be great
Bob Peckham

Back in 2005 I spent a LOT of time trying to understand why the NCRS judges did not like my LIC reproduction wing nut. Richie Cohen at LIC was adamant that his reproduction wing nut was correct, and even sent me the GM drawing of the original part number (copy attached).

It turned out that while the LIC reproduction complied with the allowable dimensions in the GM drawing, the ACTUAL wing nuts installed on C2 Corvettes up through late 1967 had distinct differences from the LIC reproductions. These differences are not obvious unless you know what to look for. The differences include:

1) Thinner metal than the LIC reproduction

2) In profile view, wings with inner profiles that lean out, rather than the rounded, inward facing profiles of the LIC reproduction that I refer to as "Mickey Mouse Ears".

3) In top view, wings that are spread out, rather than pinched in like the LIC reproduction.

These differences are subtle, but experienced NCRS judges have learned to recognize them. The reproductions sold by LIC are reasonably correct for the GM part (with the same GM part number), used after late 1967. Prior to that, the wing nuts used in production C2s had the above differences from the LIC reproduction.

Attached are a couple pages from a presentation I made in 2007 on recognizing original C2 parts. If you study the photos with reference to the three differences listed above, you may be able to recognize the differences.

Under the current "matrix" judging method used by the NCRS, the originality deduction for the LIC reproduction should be either zero or at most one point. If you really want to avoid this very small deduction, send me a PM and I will check to see if I have a nice original wing nut available. For a period of time I used to collect these and sell them, but I may not have any originals left.

The LIC wing nut should be a very small deduction (if any), but if you are determined to have an original, you should be able to find one eventually if you know what to look for.

[Mark F.]

Re: 66 L79 air cleaner wing nut

In addition to what Joe L. and Joe R. have provided (thank you both for that!), I too wondered many years ago about prevailing judging guidance stating the metal used to make the wing nut was "no thicker than a dime".

As Joe R's drawing shows, the min and max thickness numbers are 0.067" and 0.077" correspondingly.

The dime guidance was well below the min thickness as shown in the chart (meaning, many nuts may have been called "too thick" because the guidance did not comport with GM specs on the matter.

A quarter just barely breaches the min thickness, but a nickel thickness is smack dab on the upper spec limit of 0.077".
Dimensions I used come from the following website: https://www.coinnews.net/mints/coin-...lating-change/GM Wing Nut vs US COIN comparisons.jpg

[Brian M.]

Re: 66 L79 air cleaner wing nut

Was only 1 supplier used?

[Keith B.]

Re: 66 L79 air cleaner wing nut

Was only 1 supplier used?

might but how many dies to keep up with demand seeing how every single car and truck produced got one. some got chrome and others got painted. tolerances had to vairy a lot when dies wore out and fresh ones were used

[Jack M.]

Re: 66 L79 air cleaner wing nut

Attributed to John Hinckley:

"I don't know that this will ever get settled to anyone's satisfaction. In the 60's, GM was using at least 25,000 of these things every single day, from at least three different suppliers (maybe more); they were made in a progressive die setup, from very heavy stock (relatively speaking for their size and draw depth), and the dies required regular maintenance due to high wear rates. Anyone who thinks all of those wingnuts looked exactly the same doesn't understand the manufacturing process."

[Harry S.]

Re: 66 L79 air cleaner wing nut

Attributed to John Hinckley:

"I don't know that this will ever get settled to anyone's satisfaction. In the 60's, GM was using at least 25,000 of these things every single day, from at least three different suppliers (maybe more); they were made in a progressive die setup, from very heavy stock (relatively speaking for their size and draw depth), and the dies required regular maintenance due to high wear rates. Anyone who thinks all of those wingnuts looked exactly the same doesn't understand the manufacturing process."

Jack, U B correct!

[Keith B.]

Re: 66 L79 air cleaner wing nut

Jack that is spot on and I think not too many people here spent any time in a manufacture environment and been around those type of machines

[Mark F.]

Re: 66 L79 air cleaner wing nut

Attributed to John Hinckley:

"I don't know that this will ever get settled to anyone's satisfaction. In the 60's, GM was using at least 25,000 of these things every single day, from at least three different suppliers (maybe more); they were made in a progressive die setup, from very heavy stock (relatively speaking for their size and draw depth), and the dies required regular maintenance due to high wear rates. Anyone who thinks all of those wingnuts looked exactly the same doesn't understand the manufacturing process."

Thanks, Jack!

Looks like my experience in stamping plants drew me to the same conclusions John had!

[James G.]

Re: 66 L79 air cleaner wing nut

Joe,
Your illustrations are great and it's easy to see the differences.
The main issue seems to be the die shape. I photographed my original and a repro also with marked up photos.
THEN today found KEEN Corvette Parts actually makes one which is pretty close, they did take care of one issue though not quite as original.
wingnutcomparison1.jpgwingnutcomparison2.jpg

KEEN REPRO- it is struck by a different die than the LIC reproduction and closer to the original, but has a sharper radius on the bend to the wing.
Really a much better replication of the actual wing nut on the cars.
Keen_NCRS_ACwingnut.jpgKeen_NCRS_ACwingnut2.jpg