65-365

I have a 65 - 365 hp SB that came to me with what I thought were the correct, finned aluminum valve covers w/ the casting flaw. However, reading through the NCRS judging manual it stated, "A casting flaw line through the letter "o" in Corvette is not appropriate for 1965 application and is subject to deduction."

Now admittedly, I'm not going for a 100% correct, but I'm now curious what years had the casting flaw and which didn't. Obviously 65 is one of the years that was not supposed to have the flaw.

62Jeff

I've read here on the forum that March of 66 was the approximate month the mold cracked and the flaw showed up

Bill Irwin

That is correct, late production 66, and all of 67. Bill.

Bill Irwin

Now that's strange. I posted a reply, it shows but does not show under replies. Weird. Bill.

65-365

Thanks guys. Now I guess I need to find someone who needs to swap no flaw for flaw. :-)

BarryK

if i'm not mistaken, Paragon, who bought the original molds for these valve covers from GM and reproduces them, still offers them with the casting flaw removed. They are more expensive because the flaw is removed manually (all of the covers that come out of the molds have the flaw) but if you want it to be more correct they are available.
I have the original no-flaw covers for my '65 365hp and I also have a spare set of the no-flaw covers from Paragon

Donny Brass

I got a set of the really rare ones, the late 66-67 covers have a faint line and the o is not filled in like the current repops.........

too bad my car is a Nov 65 car

ctjackster

you can easily pick up some no flaw valve covers for you 65 off of ebay, these are plentiful.

if it makes you feel any better, for some reason my 65 365 (original engine) car came to me with casting flaw valve covers too - at some point in its life, the valve covers were likely removed in an environment where other finned valve covers were laying around, and flawed ones were reinstalled. Or, perhaps someone polished or otherwise did something to the original valve covers, and a subsequent owner bought some new valve covers otc (and would have gotten the flawed ones) to make it look original again. Anyhow, I picked up some Lester non-flawed valve covers off of ebay - you need to be sure the ears are in good shape and the covers haven't been hit with too much bead blasting or silver paint.

ps - you want the Lester 3767493 valve covers, for you searching.

Donny Brass

they were probably over tightened at some point and broken....

62Jeff

Hmmm, I've got a spare set like that - except mine were bought in 1981 and I used a Dremel tool to clear out the "O".

Donny your post brings up why clearing out the "O" is only part of the battle - the faint line where the mold broke is still an indicator of a late 66+ cover

I wonder how Paragon turns their valve covers until unflawed ones? Do they clean up the faint line as well?

Donny Brass

they probably have a dremel and then lightly sandblast them.. I doubt they charge enough to have them reskinned after removing the line.

Frankie the Fink

I can't figure out if mine have the flaw or not...evidently its not correct on a '61. There is definitely something going on with a faint vertical line going through the 'o' on my valve cover but don't know if it qualifies as "the flaw" ??? Its on both valve covers.

ctjackster

methinks they just use a different mold, perhaps one made using the cracked mold as the starting point, but cleaned up. I personally doubt their plan for producing non-flawed valve covers would involve manually cleaning up flawed ones.

RoadKing96

fdreano, They sure look like the ones with the flaw to me. The ones without the flaw have NO indications what so ever of even a hint of line running through the O.

What do they look like on the inside?

RK

ctjackster

Looks like they are or began life as flawed valve covers. I am sure they say "Lester 3767493" on the inside.

Two possibilities: (1) these are valve covers produced very near the beginning of the flawed valve covers run (the crack in the mold opened up over time) or (2) these have had their flaw seam worked with a dremmel or sandblasting or both.

Frankie the Fink

They are clean as all heck on the inside but I don't remember if the flaw was underneath...their numbers are both: 3767493...don't remember the "Lester" but it certainly could have been there.

GUSTO14

These look very much like someone spent some time on them. The hole in the "O" should be oblong and slanted to the right (like the open area in the "r".) This hole is much too round. Whoever did it, did a pretty nice job otherwise. You really have to remove a lot of aluminium on the fins to sand the line out. That or build them up with aluminum welding rod and then sand them down.

Good luck... GUSTO

Frankie the Fink

Well sounds like a '61 should NOT have this flaw...but I will leave well enough alone. I doubt I could do any more with the defect than has already been done and could make things much worse...

Actually, it gives the engine personality!

65-365

Can you tell the difference between the originals and the Paragon reproductions?

I have the same covers on mine. . ."o" is fine and looks right, but there is a definite line through the cover. . .unlike fdreano's covers - which to me do look like someone spent the time cleaning them up. IMHO.

Yeah, see I liked the story behind the crack. . .but alas it isn't correct. . .As I said, I'm not going for 100% correct (don't like bare steel parts for example), but it just kind of irks me that they aren't right.


Thanks for the info. . .my situation is like yours, I have the original numbers matching engine, but the valve covers obviously aren't original. I know the owner had different heads on it at one time when he was doing some Gymkhana type racing, so I can see how they got mixed up. It is just these little nuances and trivialities that are driving me crazy.

kskid

what I have seen on e-bay is that if you have the valve covers with the castingl line in the"o "they bring big money.