What you should expect When Buying A Used Holley Carburetor

Carburetors have been feeding engines  for many years, and the Holley brand name has been there for most of that period. Holley started building carburetors in 1903, but since we’ll only speaking about four barrel carburetors for this tale, we’ll pick up somewhere in the past due ’50s.

There are many types of Holley carbs available for the power-hungry enthusiast.

The particular trusty 4150 series carburetor premoere appearance in 1957. Once the crazy ’60s hit full-swing, all bets had been off, and the lowly four-barrel offered way to six and eight-barrel apps by simply multiplying the number of carburetors on top of the intake. Today, those ultra-rare, multi-carbed applications spend more time under the sizzling lights of auction houses compared to they do on the highways of The united states, so again, we’ll stick with the particular bread and butter of barrel-dom, and focus on the core associated with performance carburetion: Holley’s 4150, 4160, and 4500-series carburetors.


Both 4150 and 4160 Holley carbs utilized basically the same body, although there might be differences like mechanical or vacuum cleaner secondaries or whether the carb includes a choke mechanism or not.

If you’re scouring swap fulfills and foraging through boxes associated with fuel parts looking for that perfect carburetor for your application, you first need to know how large an unit you’ll need. That  information flows at the speed associated with light over the internet, and those who need a web link of motivation, Holley even offers a  carburetor selector   manual on their website.

Every single Holley carburetor has a list amount. For carburetors with a choke set up, the list number is the top quantity on the choke housing. The carburetor may or may not have the phrase “list” or an “L” prior to the number.

In order to at a swap meet carburetor, being aware of what model you have in your hand  could be the first step, and that’s why it’s great to look at some foundational differences among each of these three series’ of carburetors that make up the lion’s share associated with sales for Holley.


If the carburetor doesn’t have a choke assembly, the particular list  number will be clearly placed on the side of the body.

4150 And 4160 Carbs

Both 4150 and the 4160 series are usually square-bore carburetors, and both may fit on the same mounting area. The between the two is that the 4150 utilizes metering blocks between both the major and secondary fuel bowls, while the 4160 uses a metering prevent on the primary side, and a metering plate hidden inside the bowl in the secondary side.

The particular metering block has removable aircraft to help tune the fuel provide for each barrel, but  the metering plate uses drilled orifices in order to meter fuel. To adjust fuel shipping in a plate, it must be replaced, or even drilled to a larger size hole. This is an area to check when purchasing an used carburetor, as the hole might have been drilled too large for your application, as well as the person that drilled the hole might not have documented their work.


Holley 4150 carburetors will have metering prevents on both sides of the carb entire body. This allows for easier tuning plus adjustability.

The particular 4150 uses center-hung float containers front and rear, while the 4160 uses side-hung floats. The 4160 series can be converted to the 4150 and vice-versa, but usually the upgrade to a 4150 would be the most typical. Both series can be had within mechanical or vacuum secondary construction. The vacuum secondary has just a primary power valve and gas pump, while the mechanical “double-pumpers” have got accelerator pumps on both primary plus secondary circuits. Some 4150s have power valves on both circuits according to the model.

Holley 4160 carburetors use a metering plate for the secondary circuit that has precisely-sized openings to meter the fuel nourishing the rear of the carb. They are tunable, but to increase fuel, you need to substitute the plate with one having bigger holes on the bottom edge from the plate, or drill out the particular holes in the original plate. This particular plate has been drilled out plus thankfully, whoever did it recorded the particular change.


The Dominator

The 4500 series carburetor stands out from the relax, and is easily recognizable due to its dimension. Starting out at 750 cfm plus growing to double that size, the particular Dominator is definitely a high-performance carburetor. It had been originally designed in the late-’60s with regard to NASCAR, and of course enthusiasts wanted a  streetable version. The Dominator is  designed for serious performance engines, plus requires their own intake mounting because of their much larger bores.

Other Models

The Holley carburetor has advanced over the years, and in 2009, Holley presented their Street Avenger line of carburetors. The 4150 style features billet metering blocks plus base plate to help save bodyweight, and also has  vacuum secondaries plus an electric choke.


All mechanical-secondary 4150 Holley carburetors will have two gas pumps, one on the bottom part of each fuel bowl. Likewise, the particular fuel bowls for 4150 units  are different than those used on 4160 carburetors, and can be identified by having an person fuel inlet  to each gas bowl.

The particular HP series carburetor is for race or serious street performance, plus doesn’t utilize a choke mechanism. They likewise have upgrades such as down-leg boosters plus tunable air-bleeds for  fine-tuning the particular fuel curve.

Opt for the vacuum needs of the motor. Holley carburetors typically have a large vacuum cleaner port on the base plate to get PCV operation, but also consider what other ports you’ll need. You may want intake vacuum cleaner or ported-vacuum for your distributor progress. Ported vacuum would be supplied using a port on the primary metering obstruct where constant vacuum would be through any of the ports on the base dish.

You might also listen to of a 4165 series, which is also the squarebore, mechanical-secondary double-pumper with metering blocks and accelerator pumps to both circuits. The 4175 is a spread-bore-style carburetor that was designed to replace the particular QuadraJet.

The 4010 series is a square bore that may be found in either mechanical or vacuum cleaner secondary configuration, and the 4011 is really a spreadbore version of the 4010.

How Do You Tell?

Identifying Holley carburetors can go beyond looking for metering obstructs or fuel feeds, and Holley helps by issuing list  amounts. The list  number is the carburetor’s part number, and you can find it either over the choke housing (if equipped with  a choke assembly) or for the carburetor’s body.

You might or may not see the word list  or the letter “L” with the amount, but the list  number is always the very best number you’ll find in possibly place. The number below it is the day of manufacture. The list  amount will tell you how the carburetor left the particular factory, and in what size settings. It is definitely powerful information to get, and should be the first place you appearance when looking at an used carburetor. Whenever researching or ordering Holley’s “Renew Kit” , this number is exactly what you will need to know.


Typical Issues?

We asked Holley’s Keith Jessee a few questions to find out what they typically discover when the carburetors come back home in order to roost and get renewed. Here’s exactly what Keith had to say.

Chevy Hardcore: Are the biggest carburetor issues typically caused by Father Time/Mother Nature or previous owners?

Keith Jessee: The biggest problems are typically caused by the previous owner enabling Father Time and Mother Nature in order to degrade their carburetor. Lack of upkeep is the number one thing that will turn  a flawlessly-functioning carburetor into a headache. This is especially true when the carburetor is attached to a vehicle that isn’t driven frequently. The ethanol in today’s combined fuels will wreak havoc on the carburetor if left unchecked.   When the ethanol in the fuel sucks in moisture from the air, it does not only create a gunky, slimy, goo inside your carburetor, it also dries out the seals and diaphragms. In serious cases, that moisture can start in order to corrode the casting of the carburetor.

Evidence of deterioration and buildup on the bowl aspect of this block indicates that it most likely has the same amount of crud inside the passageways within the block. Be sure to clean almost everything! The jets have been removed, but additionally note the omission of a strength valve (the big circle simply above the holes for the aircraft.

Evidence of rust and buildup on the bowl aspect of this block indicates that it most likely has the same amount of crud inside the passageways within the block. Be sure to clean almost everything! The jets have been removed, but additionally note the omission of a strength valve (the big circle simply above the jet holes.

CHC: Will a normal rebuild kit be sufficient to create back a carburetor’s performance usually?

KJ: If the tough (cast) parts are intact, the rebuild kit and a can associated with carburetor cleaner is all you really need to obtain most carburetors back in operating problem.

CHC: What places would prevent this from getting the case?

KJ: There are seen some extreme cases associated with neglect, where the castings have been subjected to some serious moisture and have rusty past the point of no come back. Obviously, cracked or broken castings would have to be replaced, and that typically is not very cost effective.

The corroded power valve may reveal issues within the metering block. You can find press-fit plugs on the top-side from the block that can be removed to clean the particular passageways, but they must be reinstalled towards the same depth in the block intended for proper operation.

CHC: Are there steps that are necessary  to assure a proper rebuild, but in many cases are neglected?

KJ: It is very common for people to neglect cleansing smaller areas  like air bleeds, emulsion orifices, power valve approach restrictors, and the idle circuits which are cut into the baseplates. I recommend utilizing a can of carburetor cleaner using a stiff bristle toothbrush and becoming as thorough as possible. Make sure that each orifice or hole in the carburetor has been cleaned and rinsed out there. It’s also imperative that you utilize the correct gaskets when reassembling the particular carburetor. We have a full staff associated with knowledgeable guys on our tech range that can ensure you are buying the appropriate carburetor kit and/or gaskets.

CHC: When shopping for a Holley carburetor at swap meet, any kind of reasons to not consider a partial carburetor? Are there parts that must be there and working order for it to be regarded? Are there parts that are less required or easily located?

KJ: I would hesitate to purchase any kind of used carburetor that had the particular choke horn milled off. Whenever that choke horn was cut-off, the one number that could identify that carburetor was cut off with it. You might have discovered a high performance diamond in the tough, or a stripped main body from  an old dump truck engine. Should you find a partial carburetor with a pretty common list number, you can find alternative parts such as metering blocks, energy bowls, and base plates pretty easily.

If the carburetor is apart, check all of the posts in the carb body to be sure they are not stripped. Also, a directly edge can help you determine if the closing surfaces are straight, or at least repairable.

CHC: Whenever should  an enthusiast consider an utilized carburetor over a new offering, or even vice-versa?

KJ: You are always taking a chance on an exchange meet carburetor. It might have that will sought after 3310 or 4779 list  number that everyone knows and enjoys, but you really have to do your homework to know if this also has the correct metering blocks plus base plate that were designed for this. When you buy a new carburetor through us, that simply isn’t a problem. The only situation where I would look for an used carburetor is if I had been looking to do a numbers matching restore or some kind of period correct old style build. As cool as the brand new Gen 3 Dominators are, I am going to always have a soft spot for the early Dominator carburetors with the velocity stacks!

CHC: Is there any information that will someone shopping for an used Holley carburetor should know before plunking down their own cash?

KJ: The most typical issue we see is the customers are often misinformed on the mechanics of a carburetor: how it works, learn how to size and tune it correctly, etc ., and that’s okay! Carburetors are a complex device, and we definitely don’t expect everyone to be a carburetor expert. That’s why we have an employee of full-time Technical Service Associates available to field your questions.

From The Community forums

How do you know should you be getting a deal or someone else’s headache? We asked a few people on the forums about what they are searching for when looking for a carburetor. Here’s the actual had to say:

“I don’t bother with date codes, when the choke horn has 3310 placed on it, and it has two metering obstructs, costs $50 or less, I would like it! ” – Rtanner

“I used to buy them from swap meets when I lived within Denver. Most were in great shape plus were cheap. Folks would state they couldn’t be tuned just for altitude and would give up. Issue was, they messed them upward by changing things. I would purchase them and go to the Holley list guide and put them back to stock. I might throw them on my Camaro, make minor adjustments, and sell all of them for quadruple what I paid for all of them since I could prove they leaped. ” – 540Hotrod

Our guys talk carburetors up to 40 hours a week, and are generally there to help the customer. If you’re hesitant to quit your hard-earned cash because you possess some unanswered questions about that carburetor you have been eyeing, just give us the call! (270) 781-9741.

CHC: If an buff is wanting to return his figures matching carburetor back to its previous glory, what is their best option?

KJ: We still do carburetor restorations on a case-by-case basis. In this instance, you would call our tech collection and tell them you would like to have your own carburetor restored. At that point, we will progress up an order and give you a Holley Custom Shop tracking number to distinguish your specific carburetor. Upon its introduction, we do a thorough inspection plus take a “before” picture. Then your carburetor is replated, recolored, repaired (if needed), and rebuilt. We place your carburetor on the flow endure and set it to original stock settings (as we do along with every carburetor that leaves the particular plant). We then take a good “after” picture and ship it in return to you.

CHC: Any kind of specific benefits that someone making use of Holley’s restoration services would get?

KJ: When we recover carburetors, it is important to us that we come back it to 100-percent original, as a result of having the correct hardware holding this together. We devote a considerable amount of assets to tracking down the correct screws, linkages, levers, and so on to ensure the originality from the carburetor.

While complicated in their circuitry, carburetors are not over and above the common enthusiast’s understanding. If you are looking for any carburetor for your application, there are plenty of choices for you. Whether the box they left is brand new or dusty plus dog-eared and found at an exchange meet, Holley carbureotors are still a reliable way to make energy.

This post was originally published on this site

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