Why are Carburetor Bodies made out of Zinc?

Sorry if it's really dumb, but I was curious about this. Is it because of resistance to corrosion? Any other reason? Thanks.

 

You know, that's a really good question that I never thought to ask! Now I want to know, too!

 

The answer is money. Zinc is inexpensive and easy to cast into a "near net" shape which requires miminal secondary machining operations.

Bob

 

Not only is the material cost of zinc cheaper, it melts about 350 degrees below aluminum and flows better when melted, is less abrasive on casting tools and is easier to machine/cut than aluminum...making it cheaper for a company to use, as well as cheaper in initial cost of material...

 

Yeah, they can use metal molds to cast it to really high tolerances cheaply.

Zinc melts at a pretty low temperature, so it's a pretty fast casting operation, and the molds are cheaper to make. They use zinc for lots of detailed parts that would be difficult or more expensive to make any other way, like door handles, hood ornaments, bezels around steering columns, fuel pump bodies, fuel pressure regulator housings, etc. Stuff like toy cars (Hot Wheels) are also made out of zinc (or pot metal) for the same reasons. Pot metal is a zinc alloy with a low melting point.

 

Some of the finer detail and thinner wall sections probably would not be castable in any aluminum alloys.Most zinc alloys are able to be cast at faster speeds for cost reduction.Burl.

 

Lower temperature on the metal equals longer life on the permanant mold tooling used with diecast. Tooling is super huge mega bucks for something that complicated.

 

Hmmm.... I think I'm going to have to trying casting up a club plaque out of zinc now!

We've been doing them out of aluminum, is anything toxic released when we melt it down?

 

doesn't zinc also have some favorable corrosion properties, as compared to steel?

 

It's so re***uring to learn that using a cheaper material has historical and traditional roots. Ang you all thought making cheaper car parts was a recent invention.

 

Yes- you definitely don't want to breath zinc fumes.

 

Or my Del Taco fumes.

 

I'm confused know, my Stromberg 97's and holley 94's are made of aluminum, even some newer Carter 4bbl are aluminum as well, or am I mistaken?
They polish real nice

 

They're made out of zinc. I thought the exact same thing, because I want to polish mine.

Here's a webpage I found..

http://reviews.ebay.com/Carburetor-Body-Finishes_W0QQugidZ10000000004680950

 

Huh, I thought they were aluminum, my bad, guess I cant tell the difference.

 

Zinc polishes up to look almost like chrome, but it quickly tarnishes and winds up turning dull gray like an old galvanized fence pole again. It doesn't stay shiny nearly as long as aluminum does.

When I was a kid, I got a kit for a little die cast model of a Model A roadster pickup for Christmas, and I thought it would be cool to polish it up instead of painting it before I put it together. I spent a lot of time buffing out the pieces on a home made buffer to make it look like chrome. You could see yourself in the reflection. It looked real cool for a few weeks. Then it turned ugly dull gray again. What a waste of time that was. It just looked like I was too lazy to paint it.

If you want a club plaque to stay shiny, I wouldn't use zinc. Unless maybe you could spray it with clear lacquer or something to keep it shiny -- or have it chrome plated maybe.

 

Cheaper is not always a bad design reason. What if making them out of a higher temperature metal doubled the cost????

Ask any metal caster, there can be important quality reasons for alloy selection, and some just happen to be cheaper. If you can't make it at all due to porosity or other casting flaws that get worse with increased temperature (ie aluminum or steel), then the "best" material in the world is a poor choice.

 

I thought AFB meant aluminum four barrel.

 

Not all Carbs are made out of zinc, I was asking more in relation to 94's and 97's. In the late 50's aluminum became popular for carbs...

 

easy to cast, easy to machine, don't have to be any stronger, rust resistant, cost effective, " " " "

 

PPG has a clear etch out now you could shoot it with, then some intercoat clear (DBC500) then topcoat and would look great. Just some random info for anyone who cares, works on alum/steel too.

 

So the clear etch prevents the greying that normally happens when you clear coat polished metal?? That is an interesting product.