Replacement carb c2

[Duke W.]

Re: Replacement carb c2

It appears the problem may be with the retrofitted electric choke, in which case the Chevrolet service manuals won't have all the information you need. I don't have any experience with these electric chokes, but there are books and web sites that have service/setup information for all Holleys including the electric choke setup.

A cold start should be done by flooring the throttle and then letting completely off. This should cause the choke valve to fully close and set the fast idle cam. There is also a choke vacuum break that opens the choke valve slightly upon startup. These adjustments are usually made by bending links to achieve specified measurements and are all easy to do with the carb on the bench, but if the various adjustments are not properly set, cold start and cold drive-off performance can be poor.

The actual fast idle is set with the engine fully warmed up, and when initially started it should be about 250 revs less than the hot setting.

In my experience with unmodified L-79s, minimum acceptable idle speed is about 750, best idle quality is with the mixture screws one turn out, which is the initial recommended setting in the service manual idle speed/mixture adjustment procedure, and manifold vacuum is 14-15" Hg.

The OE 236-16 8" VAC is too aggressive, so I always recommend replacing it with a 12" B26, which easily passes the Two-Inch Rule, and then making the centrifugal curve as aggressive as possible.

It should also be verified that the VAC signal line is connected to a full time manifold vacuum source.


Duke

[Joe C.]

Re: Replacement carb c2

John,
The original 2818 used in 1965 did not use an electric choke. It had an integral choke actuated by exhaust manifold heat supplied via a hot air tube. In 1966, the intake manifolds were changed and all 2818 carbs used in this final year used a divorced choke with the "stove" located in the intake manifold.

If I were you I wouldn't waste time with that old piece of junk if your car is not a trailer queen. Take it from me......I've been through it with mine. Old castings likely have internal corrosion/defects or modifications made many years ago. In most cases, even the so called carb "restorers" won't find them. Again.........take it from me. As a matter of fact, I found one such modification in my 2818-1 carb and corrected it, after the so-called "guru" returned a very pretty but lousy running carburetor for which I paid "good money". So I fixed one problem that the so called "guru" missed, but was left with three other very annoying drivability and safety issues. I installed a Quick Fuel carburetor five years ago and the engine runs like it has EFI. No leaks as well.

As Joe L always says: "there's NO substitute for a NEW carburetor.....nothing". On this point I agree 110%.

Look at Quick Fuel instead of Holley. They are more expensive but worth every penny.

[William F.]

Re: Replacement carb c2

John,
You can purchase a new Holley, 2818, almost same appearance( some improvements such as hex heads instead slotted screw heads on bowl screws, reinforcements on body to prevent warping) as original-no chrome "hot rod "stuff from Specialty Parts Warehouse, OPP, Alabama. Only place I know of where you can purchase these OEM type Holleys for old muscle cars and Corvettes. Still not perfect, though. I had 2 of these new ones that came with pin holes in secondary floats-guess poor soldering at Holley factory.

[Joe L.]

Re: Replacement carb c2

John,
You can purchase a new Holley, 2818, almost same appearance( some improvements such as hex heads instead slotted screw heads on bowl screws, reinforcements on body to prevent warping) as original-no chrome "hot rod "stuff from Specialty Parts Warehouse, OPP, Alabama. Only place I know of where you can purchase these OEM type Holleys for old muscle cars and Corvettes. Still not perfect, though. I had 2 of these new ones that came with pin holes in secondary floats-guess poor soldering at Holley factory.

William------


I'm not completely sure, but I don't think Specialty Parts carries the 2818 anymore. In fact, I don't think they now offer any reproduction carb models with hot air chokes.

[Leif A.]

Re: Replacement carb c2

William------


I'm not completely sure, but I don't think Specialty Parts carries the 2818 anymore. In fact, I don't think they now offer any reproduction carb models with hot air chokes.

Joe,
Specialty Parts Direct still sells the Holley 3810 and 3367 with the hot air chokes, as were standard in 1966 and 1967. I spoke with them yesterday and they no longer have the 2818. Holley quit making them a few years back and they have been sold out of them for quite a while.

[Joe L.]

Re: Replacement carb c2

Joe,
Specialty Parts Direct still sells the Holley 3810 and 3367 with the hot air chokes, as were standard in 1966 and 1967. I spoke with them yesterday and they no longer have the 2818. Holley quit making them a few years back and they have been sold out of them for quite a while.

Leif------


The Holley 3810 and 3367 do not use a hot air type choke. They use an intake manifold-mounted, divorced style choke. 1965 was the last year for hot air chokes on a Corvette.

[William F.]

Re: Replacement carb c2

66 L79 had a 3367 all right, but with divorced choke, not hot air. I owned one for 35 years. If Wholesale doesn't sell a hot air choke 3367 get the divorced choke 3367, wire choke open, remove and plug hot air tube from exhaust manifold, pat it a few times to stat and enjoy. Could try to install an electric choke on the 3367 but some say difficult; I don't know.

[Leif A.]

Re: Replacement carb c2

Leif------


The Holley 3810 and 3367 do not use a hot air type choke. They use an intake manifold-mounted, divorced style choke. 1965 was the last year for hot air chokes on a Corvette.

Joe,
You, of course, are correct. I wrote that response just before bedtime and lay in bed realizing exactly what you said...I wasn't about to get up and edit my response. Thanks for doing that for me

[William F.]

Re: Replacement carb c2

But if they have a hot air choke 3367, buy one.

[Mark E.]

Re: Replacement carb c2

To clarify what the above threads say,

- The OE carb has a hot air style choke, but that model is not available new
- An electric choke carb is now installed, which isn't working properly

Correct?

If we're confident the carb is causing the drivability issues (paying heed to Duke's comments), the choices-

- Install a new Holley with a non-original electric choke
- Find and install an original style Holley, either NOS or restored

The second option is probably more $, but if this is a nice original car, may be worth the effort and cost. To help ensure satisfaction with a "restored" carb, select a source that tests on a real engine before shipping, and offers a solid return policy.

[John P.]

Re: Replacement carb c2

Thanks to all for helpful input. I decided to buy a new Holley-will report back on performance. I think This Old Carb is shot.

[John P.]

Re: Replacement carb c2

Thanks to all for helpful input. I decided to buy a new Holley-will report back on performance. I think This Old Carb is shot.