C4 hood date code etchings

[Floyd B.]

Re: C4 hood date code etchings

Mine looks like it was applied by a kindergartner using a sharp stick. Looks to be 12-14-95. It's on the passenger side forward of the wheel well (i.e. same location as the pics in the OP). I tried to use some wax to bring it out a bit more. When looking at it in person I can see that the middle number is clearly "14". The build dates of this car are:

Shipped date: 12/22/95
Engine Build (LT4): 12/19/95

IMG_2199.jpg

[Pete B.]

Re: C4 hood date code etchings

I am on the National C4 Chassis team
The "rumor" that I heard was that is was put on the line but it was just a rumor!
I have seen these a lot actually see more than not, more prevalent in the earlier C4's but no trend that I could see.
Sometimes they are there, but under the black out and harder to see. Some times you will see initials too.
Other times you can see the vibra pen or whatever was used and you can see the primer(?) in the bottom of there lettering.

Always predated the build date. From the hood maker??? hmmm maybe??

Pete

[Ed N.]

Re: C4 hood date code etchings

Pat, I checked mine and no etching on it and my car has a build date of 11/1/94.

[Pat F.]

Re: C4 hood date code etchings

Pete, if you can get in contact with Tom Barr he will give the information we learned at the South Florida Regional from the individual who worked at the company that made the C4 hoods. He claim it was done at the company where he worked. He gave quite a non-glowing endorsement of the method and dedication of the employees who made the etchings.

Ed, I left you a message as you requested.

[Pat F.]

Re: C4 hood date code etchings

Floyd, I was unable to download a full size copy of your photo. I could only get a very small photo.
Could you email a copy of the photo at fulassoc@comcast.net

[Floyd B.]

Re: C4 hood date code etchings

Done. Let me if you didn't get it or need more photos or more information.

[Pat F.]

Re: C4 hood date code etchings

Floyd, thanks for the pictures.
Mike Treece sent along four additional photos. A couple were very clear in presentation, but not in a complete date code that we are accustomed to seeing.
I am attaching one from a 1996 Grand Sport number 438. From my data bases information, I think that the build date was around March 1996. As you can see pretty clearly a 2-13 71. February 13 and then the 71. This is the second etching I have that is similar to this on a 1996 Corvette that has the last two numbers as a 71. The other 1996 had a build date of January 1996.
If anyone can help us out, you are more than welcome to chime in.
Thanks Mike for the help.

[Floyd B.]

Re: C4 hood date code etchings

In a past life I worked on hand writing recognition software. When analyzing hand writing we had to determine the human writer's intent by analyzing the individual strokes. Apparently the tool used by the line workers were crude or they did not know how to use them. Since we have examples here going back to '91 yet the skill of the workers doesn't seem to improve going into 1996, I would guess the former. If you look at the year inscription in Tom's example (i.e. after the second '-') there appears to be four strokes:

1) A straight vertical line
2) A small circle in a somewhat teardrop shape that starts and ends at the top
3) Another small circle but this one finishes with a long right-to-left stroke that gets noticeably lighter as soon as it crosses through the start point at the top of the circle. You can see it cross through the lower section of the upper circle, then touch the top of the vertical line and keep going until it ends when it is even with the "-".
4) There is a short line that appears to be added to the top of the lower circle. Perhaps this was done when the writer went back to "fix" his/her attempt at making a "6"?

Based on the context of what is being written and what we see in this photo, I am guessing this was an attempt to write "96" that went bad. The upper circle and vertical line are the two strokes that would form a "9" if they were correctly positioned. The lower circle with the short stroke added at the top are a corrected "6".

Pat,
if you get an opportunity to speak with the person who pointed this out at the FL regional, it would be interesting to ask him what was the orientation of the hood when the line workers made their inscriptions. I'm guessing it wasn't a natural or convenient writing position.

[Rex M.]

Re: C4 hood date code etchings

Pat, I'm the guy who pointed out the etched dates on some hoods at the Florida Regional. Hoods made after about 1990 were made in Shelbyville, Indiana at Gen Corp Automotive. Assembly workers were instructed to put the date / sequence number of assembly / and shift. Thus a number like 10-21-91A would mean; Oct 21st, 91st hood assembled on 1st shift. The workers moved around on different jobs every shift. There were only two shifts; A & B. Sometimes they put it on hoods, and sometimes they didn't. Sometimes it was on the left, then right. Sometimes at the front and some at the rear but usually at the front. The dates were etched with a cheap electric etcher bought at Sears. If done properly Bowling Green could check dates to find if there were a bond adhesive problem on a certain date and on what shift.

[Rex M.]

Re: C4 hood date code etchings

The hoods were assembled in Shelbyville, Indiana at Gen Corp Automotive. A cheap Sears etcher was used after the inner & outer were bonded together. It was suppose to be on the etched on the front driver's side but workers in the hood assembly area moved around "Everyday" and the training was good, so you got all kinds of variations; Some on the right, then the left, not at all, some at front, some at rear. It's neat today if you happen to have one you can read. Typically; the numbers meant; Month, day, Number assembled together that day. An "A" or "B" meant A for 1st shift and B for 2nd.

[Floyd B.]

Re: C4 hood date code etchings

Rex,

What was the typical max number of hoods made during a single shift?

[Rex M.]

Re: C4 hood date code etchings

Typical day's production around 135 Hoods or whatever Bowling Green was running. We were only a day or two ahead of their production. After the hood was installed on line it would be three or four days before the actual Vette rolled off the line.

[Floyd B.]

Re: C4 hood date code etchings

Rex,

>> Hoods made after about 1990 were made in Shelbyville, Indiana at Gen Corp Automotive

Do we interpret this to mean that hoods made prior to this time would not be expected to have this etching?

Also, what was the orientation of the hood when the worker made the etching? or did this also vary?

[Pat F.]

Re: C4 hood date code etchings

Rex, thank you very much for getting onto this subject. I have a number of questions for you and I will present them here for all to see.

I am going back and reviewing my STUFF before I put my foot in my mouth with a stupid question.

Your information at the Regional was really taken to heart by the C4 guys and I really do appreciate you helping us out.

[Rex M.]

Re: C4 hood date code etchings

Hoods made before 1990 were produced in Marion, Indiana at the General Tire & Rubber plant. Those hoods had a 2" X 3" piece of white paper/ or ticket with the jewelin date, part number, shift on it and it was molded-in on the underneath side of the hood in the very center section. The black-out hids these tickets. If you used methylene Chloride or some type paint stripper you could find the ticket. When production was moved to Shelbyville, they didn't do the tickets.