Old Cars Q&A: 2021 no. 10

Q. Arthur Newberry’s recent plea for help regarding his use of an Edelbrock 1406 carburetor atop a Chevy 283 (Feb. 15 Q&A) has a very simple solution. His use of an unidentified adapter creates a problem that quite simply cannot be solved.

As he describes, the blocking of warming exhaust gases under the carburetor induces icing difficulties in his intemperate climate. My suggestion is to acquire an intake manifold for a 300-hp Chevrolet 327, which is married to a bona fide Carter AFB series four-barrel carburetor.

The Edelbrock 1406 he bought is a “knockoff” of the venerable and excellent Carter AFB series carburetor, which ultimately eclipsed the even more venerable Carter WCFB series carburetors that equipped most all of the manufacturers’ early OHV V-8 powerplants: De Soto, Chrysler, Oldsmobile and, yes, even Mercury.

Problem solved by a bolt-on solution. The only caveat is that as editor Angelo Van Bogart notes in his “Hop In” column in the same Old Cars issue, experts who can and are qualified to correctly rebuild vintage carburetors are fast becoming scarce. If he needs help finding someone, he can call on me.
— Charles Farley, Oak Island, N.C.

Q. In response to Arthur Newberry’s problem with his carb frosting, I seem to remember my dad’s ’58 Ford with the 300-bhp 352 doing about the same thing. After several futile attempts at a cure, the thing that seemed to fix it was a spacer that fit under the carburetor and had fittings on each end for hot water from the intake manifold, through the spacer and to the by-pass fitting on the water pump. It must have worked because I don’t recall any further problems. I have an ’83 Mustang GT with a 5.0 4V that has an air cleaner with dual snorkels and each snorkel has a flexible metal hose/pipe attached to a metal cover on each exhaust manifold and there is a thermal device in each snorkel that lets either hot or cold air into the air cleaner/carburetor. I have never had a problem with that system, and it’s factory. I’m sure you can find a GM air cleaner with dual (or single) snorkel(s). My Mustang has an Edelbrock AFB which I assume is very similar to your carb, so I feel it should work for you. Hope this helps fix your problem. — Dick McCormac, via email

Q.In regards to Mr. Newberry’s question, I was first going to suggest making sure the heat riser passages were not clogged with carbon, but I can see that the intake manifold pictures (thanks, eBay) show the heat riser passages go right to the base of the carb. The carbs back then had a cast-iron base so they could take the heat. Since the carb adaptor he’s using is most likely aluminum, it blocks these passages and slows the heat from reaching the Edelbrock carb, which also has an aluminum base. My suggestion would be to find a machine shop that could mill some passages across the base of the carb adapter to allow the exhaust gasses to flow under the adaptor and heat it up. — John Gurnig, Lake Forest, Ill.

Q.This is regarding Arthur Newberry’s question about carburetor icing on his 1959 Chevy. I had a 1985 Chevy T-10 Blazer 2.8-liter V-6 with a Rochester 2SE staged two-barrel carburetor. The gasket between the carburetor and intake manifold incorporated a heating element under the primary throttle plate (see photo). It was controlled by the coolant temperature sensor through a relay that was mounted on the firewall. This was used in conjunction with a vacuum-operated THERM-AC valve located in the snorkel of the air cleaner controlled by a temperature sensor inside the air cleaner housing. This allowed intake air to be drawn over the driver side exhaust manifold during warm-up. I never experienced any icing issues.

I realize that constructing a THERM-AC system on a stock ’59 Chevy could be impractical. I mention this only because maybe there is a similar type of gasket available in the aftermarket that would accommodate the primary area of Mr. Newberry’s Edelbrock. How effective it would be without the THERM-AC set-up would remain to be seen. — Randy Larate, Scotch Plains, N.J.