Casting Flaw Question

[David D.]

What year(s) did Corvette have the casting flaw through the O on the aluminum Valve covers?

I thought the flaw started showing up in '65 and later but I keep seeing different years listed that show earlier years with casting flaw.

Thanks in Advance,
David

[Michael H.]

Re: Casting Flaw Question

What year(s) did Corvette have the casting flaw through the O on the aluminum Valve covers?

I thought the flaw started showing up in '65 and later but I keep seeing different years listed that show earlier years with casting flaw.

Thanks in Advance,
David

David,

Pretty sure that casting line first appeared some time in mid 66 production.

[Jack H.]

Re: Casting Flaw Question

Michael has this one knocked! I believe Noland Adams has the saga of the valve cover mold's repair nailed. And, the 1966 JG book calls out:

"A casting flaw line through the letter 'o' in Corvette appears at approximately VIN 17000 (March 1966)."

[John D.]

Re: Casting Flaw Question

My 67 with a sept 15, 1966 engine assembly date has one cover with the flaw and one cover without. Is that too far past the accepted date for the flaw to be reasonable?. Took the hit in judging a few years back.

[David D.]

Re: Casting Flaw Question

Thanks guys....I stand corrected.

That's why this board is so good. You get the answer(s) you need.

David

[Gary S.]

Re: Casting Flaw Question

If you decide to look for valve covers with a casting flaw, make sure you look long and hard at what is being offered. At Carlisle two years ago, I saw valve covers that had the casting flaw through the O. However, these were so ugly that no amount of work would bring them to a state that you would want them on your car. I am guessing that perhaps the original mold is now in such poor shape that the end result is these really ugly covers. There was casting flash (right word?) and extra debris all over the cover. Fwiw, I was comparing them to a pair of valve covers given to me that are actually quite nice but do have the flaw. The line through the O is the only thing differntiating my valve covers from a early 66 valve cover.

Now, if I just had my 66 back to install them on.

Gary

[David D.]

Re: Casting Flaw Question

Actually, I am looking to find me a good set of valve covers with out the casting flaw, being I have a '64.

I hear rumblings that lots of the covers offered by vendors are very ruff in exterior appearance and don't pass well.

So if anyone has a nice set with NO casting flaw please let me know.

David

[Richard P.]

Re: Casting Flaw Question

What caused the flaw? I've heard that somebody dropped the mold and broke it and it was repaired. My question is, did they only have 1 mold?
Just working on my Corvette trivia qulifications!

[Patrick H.]

Re: Casting Flaw Question

Paragon offers these covers brand new both with and without the casting flaw. They own the tooling. Check out their web site or catalog for more info.

Patrick

[Stuart F.]

Re: Casting Flaw Question

I'm proud to show my 63 with covers that have the casting flaw and admit they are replacements for those that I blew off in a crankcase explosion. I am happy that my originals took the hit and not my pan or my heads. The choke heat tube popped out of the exhaust manifold and was reusable and the rubber hose gave way too. I was lucky and only recently learned that Chevy knew about the potential problem associated with the PCV vent system (last months Vette Vues Magazine) and had a fix described in a service bulletin which called for adding a flame arrestor in the air cleaner.

Stu Fox