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Holley 4000 Carburetors (2x4 Intake Manifold) Part 1

Updated: Dec 29, 2019


When it comes to the history of Ford V-8 engines usually the Y Block gets lost somewhere between the Flathead and the FE series of well-known power plants. Not only do people recognize the Flathead and the FE series much more easily than a 292 or a 312, but most enthusiasts have greater familiarity with the parts that were bolted to these fine engines. Items such as the Stromberg carburetor, Flathead water pumps, or even the performance intake manifolds that led up to the infamous 427 side-oiler are parts that can be identified by most with just a silhouette.

Enter the Holley 4000 carburetor - the four barrel carb of choice from FoMoCo during the mid-50's until the spread bore Holley's were introduced on factory cars in 1957. Up until that time, the Holley 4000 could be found on Fords and Lincolns of the era. However, in 1957 FoMoCo did use the Holley 4000 on the 2x4 intake manifolds (ECG 9424 D) for performance packages, and they also installed the Holley 4000 for any vehicle that was blessed enough to have a VR57 Paxton McCulloch supercharger under the hood. The year prior there was an over-the-counter package that could be purchased to hop up your 312 Y Block V-8; it consisted of an improved camshaft, heads, and a 2x4 manifold for the Holley 4000s among other things. I was able to locate a technical service bulletin (TSB) that describes the kit's contents and the procedures...

The first time I had ever heard of these carburetors was way back before I even had a license. My dad, who owned a 1956 Ford Customline Victoria when he was 17, often talked to us three boys about the 312 Y Block in that car along with the 2x4 setup. Not having any photos or reference books to show us, he would describe the small four barrels and use the word "teapot" to give us an idea of what the carburetors resembled. The older I got, the more I learned as well that others would tell stories of these carbs in not so fond terms. The worst I ever heard was "towering inferno" - a reference to the Holley 4000 catching fire because of fuel that would leak from the secondary feed tubes (or other places) onto a hot manifold. Horror stories and general bad-mouthing of these units aside, I have always been intrigued by the so called "teapot" carburetor. After all, FoMoCo won a lot of NASCAR races in 1956 and 1957, beating out all other makes - check the record books. Those wins came because of men like Curtis Turner and stout torque numbers from the 312 Ford, but they all had a common denominator that today some enthusiasts disregard: the lowly Holley 4000.

1956 Fords being prepared for a NASCAR race

I do not discredit the fact that these carburetors are a different breed. For sure they seem very odd when compared to well-known versions such as a Carter, Edelbrock, Holley, or Quadrajet. And truth be known, they only proliferated a few brief years in the 50's.

One thing is for sure - the Holley 4000 is very easy to pick out of a bin of parts at a swap meet! As I recall, my first swap meet purchase at the Carlisle, Pennsylvania, fairgrounds was an ECZ-9425 A intake manifold and Holley 4000 carburetor that someone had lying on a table among a bunch of other parts. I paid $40 for the combination, and over the next few weeks I disassembled, cleaned, and rebuilt the carburetor just for kicks. Over the years I have rebuilt and tuned several of these carburetors, both the 55 and 56 versions; and I even modified a 56 version for a VS57 Paxton McCulloch supercharger which ran very well. A few of the units I rebuilt several years back went to Virginia and a man named Wayne Francis who installed them on a couple of his 1956 Fords. These cars were used in the movie Loving. Yep, the 1956 Ford driven by the main character of the movie and the police car in a few of the scenes both had Holley 4000s that I had rebuilt a few months prior. Enjoy this brief video of a break-in session on a 272 Y Block V-8 that also included a test run for one of those teapot carburetors.

"So what are you up to now?" you may ask. If you follow this blog at all you know that I already have a good Holley 1450 on the 292 in the Fairlane. I do not have any plans to change that - it makes the car an excellent driver. However, this past year I located a 1957 2x4 Y Block intake manifold, the special valley pan for this intake (more on that later), and I have had several Holley 4000s in my stash for the past several years. Maybe it's the challenge. Maybe it's just a winter project. Maybe it's the appearance of a 2x4 intake when you pop the hood. Maybe it's a bit of nostalgia for my dad just to see if I can pull off the setup. (I have heard that tuning can be frustrating.) Whatever the case, I got started this past week. Over the next few months we will work to keep you updated on the progress. At this time, I do not foresee installing this setup on the car until next summer in 2020. There is an outside chance I may be able to place it on a mule engine setup on the run stand. A number of you have already seen my posts on social media and have requested details via video. We will certainly do our best.

It seems that some of you are getting ready to rebuild your first Holley teapot. Listed below are some tips I would like to give before we begin. Keep in mind that there are generic, or common, carburetor rebuilding tips that you can find in many places. Much of what is outlined below concerns the nuances of the Holley 4000.

1. Research, research, research. In addition to owning a shop manual, I highly suggest you download the Holley manual(s) for this carburetor by visiting the website entitled: the old car manual project. There are two digital manuals on that site in a PDF that you can access for free and print, however you can only do so a page at a time. I do sell a CD (or thumb drive) here on the website that contains these manuals and much, much more. The information is invaluable.

As early the fall of 1954, Ford sent out service bulletins about the Holley 4000

2. Purchase at least ONE other core. I have never successfully rebuilt a Holley 4000 without borrowing parts from another Holley 4000. Let's face it, it is near impossible to find a gently used core, much less an NOS or NORS carb off the shelf. These things are well over 60 years old. You can find cores at swap meets, eBay, Craigslist, Facebook Marketplace, and the like.

3. Use an Ethanol Safe carb kit. Leave that NOS kit on the shelf! I highly recommend companies such as Daytona Carburetor down in Florida. You want a quality kit to begin with, but do make sure you purchase a kit with components that can withstand the corrosive issues of ethanol.

4. Replace the secondary diaphragm. Yes, this will mean a separate expense (but some of the high end kits do come with this diaphragm), but there is no sense in going through all of this work to end up with secondaries that do not open correctly.

5. Use a threaded seat for the fuel inlet needle. All of the 1955 Holley teapots, and even some 1956 models, had the smooth bore seat (this will be referenced in the video series). The issue is that a spring was used to keep the seat "seated" in the fuel bowl so that the needle could function properly. Thankfully, most all of the 4000's in 1956 had the seat that screwed into the fuel bowl inlet. Most carburetor kits will come with a threaded seat. If your fuel bowl does not have threads, you can switch to another threaded fuel bowl that has the threaded inlet or you can tap your fuel bowl. (I understand there is a company that sells a kit to assist you in this procedure.)

6. Support the base as you work. My title photo above shows a simple set up of four bolts about four inches long that places the base on stilts. Because of the way the butterflies actuate, and because of the way the linkage is designed, the stilts give good access to remove and replace hardware as you work on the carburetor.

7. Rebuild according to your distributor choice. Not to hit a nerve, but there are many who do not understand that in 1954-56 the "load-o-matic" distributor (vacuum advance ONLY) on the Y Block engines was a peculiarity. Each carburetor was MATCHED to the distributor in particular. Mixing and matching modern carbs to vacuum only load-o-matics, or Holley 4000's or two barrel Holley 94's to 1957-64 distributors that have both vacuum and mechanical advance needs to be seriously examined. I highly suggest that you upgrade your carburetor's vacuum signal (prepping it for a 1957+ distributor) by performing the procedure outlined by Ted Eaton. That procedure can be found on the website for his machine shop: Eaton Balancing

6. Consider using an electric choke. The Holley part number you need is 45-258. Unless you are working on a show car that will be judged for originality, I highly suggest you stay away from the problematic choke that was operated by exhaust heat and use an electric choke instead.

That's probably enough content for this first post. Looking back up through all of this information the introductory material is a lot to digest. Let me leave you with another reason this series of articles could be helpful. It is very difficult to find any information on the Holley 4000 in printed form. Take this Holley book on carburetors that was written in the 1970's...

When you examine the table of contents, there is nothing concerning the Holley 4000. Basically, all of the information begins with the 1957 models and leads the reader up to the present day of the time and the designs available when the book was printed.

I do not expect the blog series to be complete and unbroken because I may pick up projects and make other posts as we go along, but subscribers can use the category listing at the top of the main web page of the blog to sort.

The Hot Rod Reverend

aka Daniel Jessup


Nov 06, 2022

how do you stake secondary tube washers and o rings

Daniel Jessup
Daniel Jessup
Sep 05, 2023
Replying to

I use a flat surface for the carburetor base (or lid), insert the o-ring, insert washer, then find a 1/4" drive socket whose OD will fit inside the bore. I like to use a C-clamp or a pair of welding vise grips to hold the socket in position. I use an awl and a hammer to do the staking in 3 positions.

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