magnesium valve covers

[Bryan C. Seery]

I have come across some valve covers lately, and I am a little confused. A friend said I should ask about them here.

They are what I thought were aluminum 7 fin Corvette valve covers. They are casting / part numbers 14025553 for the left, and 14025554 for the right. Someone told me they are not aluminum, and by the part numbers are magnesium instead.

A: How can I find the difference - how can I tell aluminum from mag?
B: are they worth more or less if they are mag? are the magnesium covers rare or common?

[Clem Z.]

Re: magnesium valve covers

my source says they are 1978-82 L 82 type cover painted black with brushed fins and are aluminum. mag covers would weight less than alum of the same design. GM sells mag covers under part # 10055781 and 782 and these covers fit production corvette alum heads

[steve principle]

[Bryan C. Seery]

Re: Did you try asking this on the C3 CF?

There area a pair on E-bay now, but the guy does not know what he has.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=34202&item=2423686060

the auction is dead in about 3 hours.




EBay auction - possible mag. valve covers

[G B.]

I can't look away

Reading technical answers on the CorvetteForum is like watching a continuous train wreck in slo-mo. It is simply fascinating to me. Where else can you find someone who times his engine AFTER top dead center? And if you're not running an 850 Holley double-pumper on the street (with your distributor vacuum advance disconnected), you just ain't got no mud.

But I do have to hand it to them. The posters there are the only mid-year owners who can make one of those cheap brass radiators fit and cool a small block car. Maybe it's the Water Wetter and braided hose covers that they use. Or I guess it could be the double-pumper.

[Joe L.]

Re: magnesium valve covers

Brian and Clem-----

The GM #14025553 and GM #14025554 valve covers are, indeed, cast from magnesium. However, that does not mean that's necessarily what you have. Here's the story:

The above-referenced valve covers were originally used on all 81-82 Corvettes. ALL of these covers were coated with a black exterior finish, except for the tops of the ribs. If you have a set which meets this criteria AND which has ONLY these numbers cast on the underside, then you very likely have the original, magnesium covers.

Most sets of these, though, that I have seen have DUAL sets of part numbers cast on the underside. They will be like this:

14025553 L.H. MAG

14025554 R.H. MAG

464667 L.H. ALUM

464668 R.H. ALUM

On some, the 464667 and 464668 may be replaced by 474207 and 474208 or other numbers.

If you have a set of valve covers which have the dual sets of numbers and they are natural aluminum, then they are NOT the magnesium variety.

If you have a set which are coated black and have the dual sets of numbers, then they may be either the aluminum or the magnesium. The 464667 and 464668 were used for 78-80 Corvettes with L-82, were coated black, but were cast of aluminum.

In the latter case, you have to identify the valve covers by looking at the exposed metal on the underside or, better, the exposed metal on the ribs. Magnesium, after oxidation, is a darker, silver colored metal than oxidized aluminum.

The above-referenced magnesium valve covers are not particularly rare. That's because the 464667 and 464668 were replaced, for SERVICE, in about 1981 by the 81-82 magnesium covers. The 14025553 and 14025554 were then sold in SERVICE to replace all 78-80 L-82 and 81-82 until they were discontinued in June, 1989 and April, 1990, respectively. I'm sure that many sets were sold in this time period for SERVICE as well as "upgrade" applications for all mannner of Chevrolet small blocks. However, when they were discontininued, they were replaced by the very same valve covers they replaced in 1981----the black coated, aluminum GM #464667 and 464668. This is very unusual in the annals of GM parts. The 464667 and 464668 were both finally discontinued in the last few years.

By the way, after 1982, Chevrolet continued to use magnesium valve covers for all Corvettes through 1992. Of course, these were of a completely different design than the 80-82, but they were all magnesium. Then, in 1993 they switched to the black, "composite" covers. In the summer of 1992 when I toured the Flint V-8 engine plant and first saw these valve covers being installed on 1993 Corvette engines (the 93s had not started production yet as the 1,000,000 Corvette [a 92] was being built the very same day that we toured the engine plant), I couldn't believe my eyes. In fact, I told one of the assembly workers that they must be going to put some kind of a cover over them when they assembled the cars at Bowling Green. But, they didn't. I've never gotten over it!

[Joe L.]

Re: I can't look away

Jerry-----

Amen!

[Joe L.]

Re: Did you try asking this on the C3 CF?

Steve-----

regarding CF posters with over 10,000 messages:

Possibly, but not necessarily. Folks over there are allowed to post WAY, WAY off-topic, even in the supposedly "technical" forums. Plus, the "off topic" forum lets folks post just about anything they want to----Corvette-related or otherwise (and most of it is TOTALLY unrelated to Corvettes). So, folks can easily post 10,000 messages and not even know a Corvette from a Thunderbird.

That's NOT to say that there are no knowledgeable folks over there; there are many. But, you don't have to be knowledgeable to post 10,000 messages.

[Bryan C. Seery]

Re: Did you try asking this on the C3 CF?

Next time you stop in at the Corvette Forum, you will recognize me as "BSeery", in the C3 section.

13,424 posts. But I don't give a damn about post counts. We know who knows their stuff, and we know which people are just post *****s.

[Ed Jennings]

Re: I can't look away

Seems like I regognize a lot of the same folks on this forum as the ones on the CF forum. Matter of fact, don't I see an occasional "Jerry Bramlett" post?

[G B.]

I are one

I even own a double-pumper.

[steve principle]

[Clem Z.]

Re: What is a post *****?

up close and personal???

[Duke W.]

Re: What is a post *****?

The are some who are more concerned with their post count than the usefulness or quality of what they write.

Duke

[Geoff C.]

Re: Did you try asking this on the C3 CF?

Joe

Up by you I knew two post *****s in Vallejo. Now that is or was a tough US Navy town. I am not certain of their affiliation with the US Navy as they were out of uniform at the time.

Geoffrey Coenen