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What I am asking is if a real window sticker (a window sticker that is determined to be authentic) and lists the YJ8 option is sufficient documentation that the car in question originally came with the YJ8 wheels.
Lets say for the sake of argument that the window sticker is the real deal, and the whelles on the car are 100% correct 1973 YJ8 wheels.
You may recall that in 1973 the YJ8 option specified 5 aluminum wheels, so the spare will also be a YJ8 wheel. That wheel is available for inspection / judging.
NCRS says that any 1973 presented for judging for YJ8 wheels must have "sufficient documentation" that the car being presented actually had those wheels installed at the factory. I was asking what NCRS considers sufficient documentation.
Now, if I had a 73 that was documented as built for a GM executive, and has the original tank sticker, and has the original window sticker, and has photos of the car when delivered, all indicating that the YJ8 wheels were on the car, that would probably be sufficient.
Unfortunately, most of the time we do not get that lucky with documentation, etc.
The reason I say GM executive is that I think the car would need to have some sort of "excuse / reason" for having wheels on it that are not approved for production.
The one car that I know FOR SURE was delivered with the 1973 YJ8 wheel is the 1974 454 coupe that Zora Duntov took with him into retirement. But I have never seen a 1973 Corvette with even a hint of original YJ8 wheels.
And yes, I do think this was / is a good discussion.
Yes, the company line has always been 'porosity' as the problem. But it was actually deeper than that...Weren't the two 'editions' of the YJ8 made by two different manufacturers? Western wheel and Kelsey-Hayes.
As I've been given to understand, manufacturing defects, including porosity was the reason the Chevy 'took the contract back' and gave it to K-H. Besides a 25 years of collaboration between the companies
As an Engineer I have done this myself...switched from one Mfg. to another because of incessant quality problems. In my industry..2% reject rate will get some big scrutiny. Six-Sigma (which wasn't followed then) basically says 'defects at 4ea. in 10,000.'
"What would ya'll say if I told you that the Chevrolet lab test results do NOT specify porosity problems as the reason for cancelling the wheel option in 1973, which is the most often claimed reason for the cancellation."
So what was the real reason according to the documents?
Every time I read a NCRS based thread I am glad that I chose to go restomod , I am clearly not cut out for all this heated debate.
Anyway, to answer the original question:
Just so I am clear in my understanding: There is a known good window sticker that shows the option, and the car physically has the option installed when we look at it?
If as you say we are taking that the window sticker is real, why would you not take the window sticker as proof of the option? The window sticker is a factory generated piece of paper based off of the build sheet for the car. If that does not qualify as 'sufficient documentation' then I am not sure what would.
Let's put that in a different context:
"Sir, I see that you have an official birth certificate. I also can see that you are standing in front of me so you are a person however I am just not convinced that you are a real person." What??
Last edited by PainfullySlow; Apr 21, 2019 at 07:47 AM.
Reason: Came out too harsh
.....here's another scenario. What if you truly had one of the real 1973 Corvettes that had the YJ8's and you had the original window sticker, but the car no longer had it's YJ8 wheels and had the standard AZ rallys on it. If it was being judged at an NCRS show, how much of a deduction would it be for NOT having the original wheels?
"What would ya'll say if I told you that the Chevrolet lab test results do NOT specify porosity problems as the reason for cancelling the wheel option in 1973, which is the most often claimed reason for the cancellation."
So what was the real reason according to the documents?
Repeated stress testing revealed structural defects in the wheels.
I am going to write that article for The Restorer like I promise John Amgwert 20 years ago.
If the parts on the car are appropriate for the production build date, NCRS wouldn't deduct any points for 'originality'...maybe for condition, but not for being the "correct" part. At least, that's my understanding. If that were not the case, there would be MANY Top Flight cars which would never have received an award. NCRS does not have any documentation on the factory configuration per build sheet for a specific vehicle (other than that provided by the car owner for that car). Basically, if it "appears" to be correct, it is judged to be correct.
Correct configuration rally wheels on a car which was originally built with YJ8 wheels should not receive a deduction.
That's what I was thinking. Correct me if I'm wrong, but I could have sworn I read somewhere that the early production YJ8's in '76 were heavier than the later YJ8's. So obv based on that there are different ratios of alloys to choose from when casting.
Yes, that's where I got the pictures. A couple excerpts from the article, "In September, even before the new models were introduced to the public, a van containing four new Corvettes arrived at C/D's Long Island proving grounds, New York National Speedway." "There is another 35 pounds to be saved — compared to the standard equipment steel wheels with hub caps and trim rings — if you go for the optional cast aluminum wheels. The new Corvette wheels are eight inches wide, as are the steel ones they replace, but the weight reduction, particularly when it is all unsprung, gives this option a functional importance rather than just flashy styling. The wheels are not made by Chevrolet but rather by American Racing Equipment in California, the company famous for the original "American Mags." The Corvette wheels, however, will not have the corrosion problems of real magnesium wheels because aluminum is all but indifferent to road salts. Duntov, based on his experience with optional aluminum wheels on 1963 and 1964 Corvettes, is confident of that."
Note these cars have regular Michigan license plates and inspection stickers and were driven on the street.
No, structural defects such as cracking and metal "pealing" off of the wheel.
Somewhere I have a picture (a real hard copy picture) of one of the wheels on Zora's 74 (which is now in the National Corvette Museum) with a slice of metal pealing off of the surface of the wheel. The darn thing was still holding air at the time. I took the photo in 1990, when the car was owned by Les Bieri of Hampton, VA. Les had just bought the car from Zora, in a deal facilitated by Dan Gale, for $100 large.
If Les Bieri's name sounds familiar, it might be because he was one of the 3 owners of 1953 Corvette serial #3, when it was purchased from Ed Thiebaud. Three guys went into the deal together (Les Bieri, Howard Kirsch, and John Amgwert). The car was restored by them, and I think Howard Kirsch bought out the interests of Les Bieri and John Amgwert.
Anyway, I was living in the Norfolk / Hampton area at the time, and Les was kind enough to let me come over a photograph the YJ8 wheels on the car. He even let me take two of the wheels off of the car so I could photograph the back side markings as well.
No, structural defects such as cracking and metal "pealing" off of the wheel.
Somewhere I have a picture (a real hard copy picture) of one of the wheels on Zora's 74 (which is now in the National Corvette Museum) with a slice of metal pealing off of the surface of the wheel. The darn thing was still holding air at the time. I took the photo in 1990, when the car was owned by Les Bieri of Hampton, VA. Les had just bought the car from Zora, in a deal facilitated by Dan Gale, for $100 large.
If Les Bieri's name sounds familiar, it might be because he was one of the 3 owners of 1953 Corvette serial #3, when it was purchased from Ed Thiebaud. Three guys went into the deal together (Les Bieri, Howard Kirsch, and John Amgwert). The car was restored by them, and I think Howard Kirsch bought out the interests of Les Bieri and John Amgwert.
Anyway, I was living in the Norfolk / Hampton area at the time, and Les was kind enough to let me come over a photograph the YJ8 wheels on the car. He even let me take two of the wheels off of the car so I could photograph the back side markings as well.
What you are describing is either contamination/alloy selection OR too rapid cooling/not correctly designed molds causing stresses in the casting - That's from the actual aluminum pour or forging.
What you are describing is either contamination/alloy selection OR too rapid cooling/not correctly designed molds causing stresses in the casting - That's from the actual aluminum pour or forging.
this correct. Alloy cooling in mold. Also poor heat treating or design, lateral strength spoke design (thickness)...etc..
porosity primary functional failure would be loss of air...leakers..currently now all checked with helium.
Last edited by interpon; Feb 18, 2021 at 04:27 PM.
.....here's another scenario. What if you truly had one of the real 1973 Corvettes that had the YJ8's and you had the original window sticker, but the car no longer had it's YJ8 wheels and had the standard AZ rallys on it. If it was being judged at an NCRS show, how much of a deduction would it be for NOT having the original wheels?
Paul
If they had proper documentation the deduction would be 80% of 16 originality points or 3.2 rounded down to 3 would be 13 Points deduction for the 4 rims installed properly. So if the rims look in perfect condition then since they had at least 10% originality points they could get all the condition points 12. As for the spare wheel would fall into the same position 4 points for originality 80% deduction .8 round up to 1 point 3 point deduction but all condition points 10% rule.
So for a total deduction of 14 points out of a possible 35 points. Not as bad as one would think. Since they were installed properly. Now it the rims were dated properly that could change everything again. CDCIF
That would be my take away other judges may have a different opinion.
I have much enjoyed your information on these wheels. I have only one Corvette I ever wanted a 1973 454 blue green 4sp. Bought it in 1986 after 13 years of waiting. It came with the wheels after two prior owners. Due to a picture I saw of a transporter with all 73 vettes and all had the cast wheels ( which seems to contradict what you guys have been discussing, since only 3 were ordered.) Regardless to have my car look original knowing the wheels were most likely not I painted the center hub area black. It appears your picture of Duntov's 74 has black center hubs ( where lugs are) Is this the correct look and is it unique to the 73 wheels?
Last edited by 73454Stingray; Apr 7, 2020 at 05:33 PM.
This doesn't add anything to the conversation, but I ordered my 73 in Aug. 72 with the aluminum wheels and of course mine came without them.
I wasn't even notified about the change, when I picked it up in December without them, was just told that they were discounted.
, I am clearly not cut out for all this heated debate.
