Technical My Crazy Dual Quad Carter AFB Restoration

So... I got this crazy idea I wanted a dual quad set-up as an optional induction for a future 327 Chevy. I looked at a few Edelbrock C26 manifolds but wanted something a bit different. I ended up with this lightly used Weiand WCV327. After some clean up I had to do a little resurfacing of the thermostat housing surface, then a blast with some aluminum oxide media, rinse/dry/WD40 and into a bag and box it went.

But…….looking at the port runner layout I realized it does not have the 180 Deg. design like the Edelbrock or Chevrolet manifolds. Will it run as well? Why did Weiand do this? It’s different alright.


Next, I needed some carburetors. The easy way out would have been to just buy some new Weber/Edelbrocks, but again, I wanted something different. I could have even done some WCFB’s but instead bought a matching pair of 500 CFM Competition AFB’s. Having raced with nothing but Holley’s for years I kinda wanted to try them. I remembered a few guys back in the day running pretty well with them.



I thought no big deal. Clean em up, throw in a couple rebuild kits, done. Right?
WRONG! More to follow...

 

Make the linkage 1:1 not progressive. You want both front butterfly's to open at the same time. Jon Carb King knows these dual 500 cfm deals very well.

 

Definitely going to be 1:1. Idle screws come into play as well. I contacted Carb King a while back and he say's there is little documentation on these. He said only in a couple of Performance catalogs do they list anything. After much research I have determined they do have the original parts.

 

Supposedly these were in dry storage in Georgia for the last 20 years. The castings have quite a few small dents and sort of blotchy dark stains in the Zamac (Aluminum alloy) that will not clean up. Probably the humidity. There is light corrosion on one of the secondary air doors. The Zink chromate is all but gone on the Steel parts. The primary throttle arms on these competition models were originally Nickel plated but these are not so pretty any more.

 

Pretty hard to get something different when using a sbc like everyone else does.

 

I was referring to the induction system but hey I am not ashamed. 327's are some of the best dam small block V8 engines ever built.

 

I'm watching. Its always nice to see it done correctly .

 

Thanks lumpy 63.

The full tear down included drilling out the ends of the brass throttle blade screws which are peened with some sort of tool from the factory to prevent them from coming out. This makes them easy to remove with out braking the heads off. One of the carbs had a bent secondary throttle shaft. I tried to straighten it which is nearly impossible because of the slot for the blades. I finally gave up and bought a cheap 625 cfm donor carb thinking it had the same shaft. Wrong again. It is longer. So out comes the dial caliper, scribe and the hack saw. Having no lathe I cut it a tad long, chucked it up in the drill press and brought the end down on a mill file. Machined the hard way +/- .005" done.

You can see in this picture one of the Primary lever arms is also bent but luckily, not the shaft. Easy fix.

 

Can't argue that 327s are good. I agree. But they look just the same as any other sbc to most people. Regardless of induction. But duel 4s looks better than most.

 

I have a 327 in my 29 roadster , has a factory chevy dual quad manifold with adapters for two edelbrock 500 cfm carbs . I removed the chokes and all the Edelbrock tags to make it look decent and it runs really hard with a 30 30 cam and a 4spd. But I really like what you are doing.

 

Well I have the induction, a Mallory Double life, some Cal Custom 9 fins and a pair of these for those with a discerning eye.

 

I've found that buying 3 carbs might get you enough parts to make 2 of them work

Looks like fun. Thanks for sharing. What is the number on these carbs?

 

The time came to remove those fuggly badges. They're too beat up to restore and impossible to find. They are anchored with steel blind rivet like fasteners with a spiral kind of knurl on the shank. Very difficult to drill out and remove these without damaging the castings and crapping up their holes.

 

Thanks Jim, Yep, that's definitely the case here. 4761S No chokes. Hang on it get better.

 

Watching.
Thanks for sharing!

 

To remove some of the dents and damage I used a small body hammer and was actually able tap and displace some of the material back where it belonged. After dressing the flat areas with a file and a little rounding over here and there they were looking a lot better.

When you look through a pair of magnifiers you realize there's a lot of flashing and burrs from the factory. Even the steel parts are kind of rough.

 

After the usual high concentration of Dawn dish soap in near boiling water whatever grease was gone but they looked like I hadn't done anything. I want some eye candy and these things look like a pair of turds.

Carb cleaner did nothing. What ever those blackish stains were they were going to take some work. Time to test some chemicals on that donor carb.

Alkaline cleaners like Super Clean and Oven cleaner both Sodium Hydroxide just made the castings darker.

I had read about de-smutting aluminum and Zink alloy castings. Apparently Nitric acid was the best but is now very difficult to find unless your in an appropriate business. Muriatic, Sulfuric, and Phosphoric acids all mixed 50/50 with water and applied to a small area with a cotton swab had little effect on the blotchiness and dark stains but it did brighten them up a bit.

Next was Soda Blasting outdoors with a chee-po HF blast gun. That was a mess so I tried wet soda. That was a wet mess but the castings did have an improved finish.

Finally, I sourced some very fine glass beads (#12) for my tiny blast cabinet. these are .002" to .004" in diameter. The trick was to lower the air pressure to about 50 psi. and of course make sure all passages were rinsed and cleaned out well afterwards.



Shazam!

 

That wagon is long gone. It had the stock 235 6 cyl. Was going to fit a 292 6cyl into it. But got a good offer and sold it. My current build is an A model with a 221 flathead. The sbf and sbc are just getting a bit generic in almost any modified car. So they are getting boring. There are a lot of other cool choices out there.

 

Nice Job on the restoration. Thanks for taking us along.

 

If you really a die-hard on the appearance of the carb body's why not, since they are aluminum alloy have them cadmium plated. Cadmium plating is a metallic silver, soft coating that can be deposited on various base materials such as steel, copper, iron, brass and aluminum. It is prized for its corrosion resistance, lubricity, chemical resistance, ductility, and ease of solderability (stolen off the internet while checking my spelling).

 

Cool! Let’s see what you have done on the A that’s not 1-800-chk-book. Oh, and how about what you’ve collected for the 221 too.

 

Thanks Rod1.

 

Cadmium plating is very toxic and has been largely phased out and replaced with Zink Chromate. It is nearly impossible to get anything to electroplate evenly on such a complex part, especially the inside features. You can get fair results on something like a Rochester 4GC if you have a large enough tank and rotate the part during plating.

The AFB bodies and many others were bare as cast Zamak. When something like a 4GC was new there was enough Zink content in the material to take a yellow Chromate which does offer corrosion resistance but is sacrificial over time.

 

After looking at the various re-finishing options for the steel parts like carb paint, Cerakote, or having them professionally plated I decided to invest in a small Zink Chromate plating system. This would get me as close to original finishes as possible.

I then set out to collect everything I would need while trying to keep the cost down. I also needed a power supply, fish tank heaters, more plastic buckets, spray bottle, nitrile gloves, copper wire, a way to measure temperature, and a lot of distilled water. Fortunately, I already had a proper respirator.

Setting it all up was next. $11.00 in 1" x 2" furring lumber, some left over plywood from another project, some left over deck screws and some left over 1/2" copper tubing from a plumbing job also helped with the cost.

 

Not aluminum? Huh....

 

Not quite. From what I understand it is an aluminum alloy. This is from Wikipedia;

The name zamak is an acronym of the German names for the metals of which the alloys are composed: Zink (zinc), Aluminium, Magnesium and Kupfer (copper).[2] The New Jersey Zinc Company developed zamak alloys in 1929.

I believe most carbs were pressure cast from Zamak 3. There are other Zamak alloy's.

 

A 50/50 bath of Phosphoric acid (Concrete cleaner) and water easily stripped off the old Zink/Chromate from the steel parts. The parts were then deburred and polished as needed with 220, 400, and 600 grit wet and dry paper. The quickest way was to chuck the screws in the drill press, wire brush the threads, the polish the heads with the paper. The more complicated parts were buffed with a Dremel using small scotch brite wheels. The idea was to produce a better finished part without spending the rest of my life on this.

The Nickel plated primary shaft arms which are welded to the primary shafts were stripped by blasting them with Aluminum Oxide abrasive but only after protecting the shaft surface with masking tape. The final step before degreasing was to glass bead every thing.

 

One of the keys to successful plating is calculating the surface area of each part or batch of parts. It doesn't have to be exact but it needs to be close. This is critical for determining the DC current needed. The plating vendors site has some helpful online calculators for doing this. I bought a 30 volt 10 amp constant current power supply from ePay for $70. Relatively cheap.

 

If you need any photos or any measurements I have a pair of 500's as well.
I did the hot soapy water scrub, then followed that with Eagle One Mag wheel cleaner.

 

Next, the parts are wired with 18 gauge copper wire. The copper wire often comes with a lacquer coating which needs to be removed with acetone before wiring.

From there they go into hot degrease at 150 deg. F (min.) for a minimum of 5 minutes (I soaked them for 20 min)
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I used a homemade rack fabricated from 3/32 TIG welding rod to hang the parts in a $30 crock pot. A two channel Barbeque meat thermometer/timer was used to monitor the temps.

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