Another Tire Date Code Question

[Tom R.]

Re: Another Tire Date Code Question

Hi Tom
Sorry for the short explanation. Terry is correct.
It is the 12th week of 1971, I don;t have a 71 calender but it is the 3rd week of March in 1971.
Thanks, Grant

Grant

What I'm getting at is the codes.

How does C compute to 12wk...what would the 13th code be, 14th? 15th

And than how does D compute to 71? What would 70 be? And than is

68=A
69=B
70=C
71=D

[Bryan M.]

Re: Another Tire Date Code Question

Bryan,

The calender IS in my third edition -- page 116. Perhaps I got a special edition, but it has no autographs in it.

Yes, it will be too early for your 1972 since all those tires, and 2/3 of 1971 production, should have the Federally mandated longer code with the last three numbers indicating week and year. No one will know what that early code is, but the latest it could be is first quarter of 1971 -- which coincidently it is.

The rule of thumb for dates (except window glass and other items as specified in the TIM&JG) is six months prior to the car build. There is no way to fit the first quarter of 1971 into six months before your end of April 1972 car build, regardless of how much you push and squeeze.

The Judging Reference Manual should have some guidelines for out of date tires, but failing that the rule of thumb (my, my we are all thumbs tonight) is 20% of the available originality points is assigned to each of the originality variables.

Repeat after me class:

Configuration
Completeness
Installation
Date
Finish

Five variables at 20% each = 100%

Sorry Terry, I see it now, I got confused. I thought I was looking for some type of tire date code interpretation calender under the tire section in the
the manual.
Configuration
Completeness
Installation
Date
Finish
Thanks teach!

[Bryan M.]

Re: Another Tire Date Code Question

HI Bryan
In a perfect world is having the original spare in your tub. Well it doesn't happen that often.
I have been researching for many years now as to the correct dated spare for my car and talking to people with original cars and with original spares.
The furthest date I've seen is approximately 2 months and sometimes 3 months from the assembly date of the car. The most common is the spare is 1 month from the assembly date of the car. I don't know what the other 4 tires are on the car but it must be also very close to the spare. Incidentally the date of the spare rim is usually predated about a week before the date of the tire.
I had found a 69 mint tire that was used very little. The date on the rim was a 69 but the black wall tire was dated late 71. So I guess someone put on NOS tire from the 70's on the 69 rim.


You should find a 72 spare with the months dated Jan(late) feb or March.
Hope this helps.
Grant

Grant,
I'll have to check the rim date code out. I guess I'll hang on to this tire as my spare until I find a correctly dated 72. If that day ever comes.

[Terry M.]

Re: Another Tire Date Code Question

Tom,
You are trying to fit the tire date code into the pattern of the window glass. It doesn't work that way.

There is a chart, and the two letters seem to change randomly as time marches on. Actually there are three or four charts depending on the decade the tire was made. The Goodyear proprietary codes changed character length in different decades as well. They seem to really have gone out of their way to encrypt the tire codes before the Feds stepped in. That is probably one of the things that lead to the government intervention.

[Tom R.]

Re: Another Tire Date Code Question

Tom,
You are trying to fit the tire date code into the pattern of the window glass. It doesn't work that way.

Your right...looking for a pattern of sorts.

There is a chart, and the two letters seem to change randomly as time marches on. Actually there are three or four charts depending on the decade the tire was made. The Goodyear proprietary codes changed character length in different decades as well. They seem to really have gone out of their way to encrypt the tire codes before the Feds stepped in. That is probably one of the things that lead to the government intervention.

Is there a source for these but than it would have to include all manufacturers of Corvettes during this period?

[Terry M.]

Re: Another Tire Date Code Question

As far as I know only the Goodyear codes for 1968-1971 have been published. The other manufacturers and the Goodyear codes for earlier tires are still proprietary. The guy who published the big 1969 book, Bizzko (I know I have that name wrong, but it is as close as I can do off the top of my head), published them.

If we had codes from all, or even most, of the manufacturers, then I think they should ALL be published -- but I think it is not fair to ALL car owners to reveal only the codes for one manufacturer.

I don't know where others got the codes, but my source asked me not to make them public, and although he has passed on I intend to honor his request. In my mind it has more to do with honor than it does judging Corvettes. I know not everyone will agree, but there are some things more important than Corvettes.