What are the pros and cons of runnning a holley compared to the edelbrock carb? This will be mostly a street driven car and once it is tuned will not be played with every week. Which one has the most driveability? Looking at the 750 cfm range.

This is o-so-subjective... What are you replacing or what is your car plumbed and setup for linkage wise? Have you tuned either carb before? Are you talking about buying new or picking up used? I prefer Holley but have a lot of experience playing with them compared to an Edelbrock. Holleys have more individual circuits that can be tuned so from a simplisity stand point the Edelbrock may get a plus for that. From a getting rid of that problem standpoint the Holley's many circuits may be a bonus though... Both carbs once tuned properly don't require further or continous tuning. I know that isn't the popular opinion but I haven't touched my Holley 670 Avenger in about 3 years. Before that I had a Holley 780 that I didn't touch for about 3 years... Both never skipped a beat. As far as gas mileage, popular opinion will say the Edelbrock but again my experiences with Holley have been great... The 780 got me 24mpg @ 60 mph feeding a sbc 383 with an overdrive and 3.73 gears. The 670 has seen 22 mpg @ 70mph + with the same 383, OD and 3.42 gears... I can't say if another carb would have done better.

I think the botton line is what you are comfortable with tuning and keep that in mind as others reply. For more insight into the Holley, check the Tech tab above and follow the Series 2 link.

I have tuned Holleys in the past. Being from the midwest and in drag racing situation, jetting was an issue depending on the weather. The car has a 500 cfm Edelbrock now. Have not tuned it at all. Drives nice but I have not played with it. It came with the car and is to small and needs to be replaced.

Carbs require attention when people dont change filters or change parts that affect booster signal/vac, gearing or weight of the car, No carb is gonna be dead on all year round in every weather condition, some people choose to go to the extreme of adjusting for weather conditions I dont. I think the holley is hands down a better performer and easy to maintain.

Dennis said it very well. It depends on what you like. As far as performance the Holly is far better than the Edelbrock. When I get asked this question I usually say, the Edelbrock is great for street rods and people that don't know or want to learn how to tune a carb. You can pretty much take them out of the box, adjust the air misture screws for highest idle or vacuum and the carb will run fine. You can just be in the ballpark and they will run decent. With a Holley you need to pay a little more attention to detail when tuning but, the trade off is better performance.

We don't know enough about the car, engine, etc.. to get real specific. If it's mild and will never be raced the Edelbrock is fine. If it is a little more performance oriented I would go with a Holley style carb. Since you already have the Edelbrock on there and it runs fine, it would be easy to drop another Edelbrock back on, no linkage issues, air cleaner issues, etc..

Whenever I read about carb tuning gurus, they all seem to be tuning................Holleys :thumbsup:

If you know holleys stick with it, if you want to learn a new trick get an Edelbrock.

There was one on my car when I bought it which I tuned hot and cold starts were a pain... threw across the garage and put the Holley on, it's what I know.

most people go with holley because they can be tuned easier over the edelbrock performer series and on the edelbrocks from what i hear it is hard to eliminate the stumbling off the line. for the street i say holley easier to tune, power valves, you can adjust the cams in them, they do better on the street then an edelbrock. if you try to turn hard with an edelbrock the car may stall as edelbrocks are designed for un and down where holleys are designed for side to side movement. holley is virtually the same as a proform or demon carb.

I much prefer the Holley.... its all about what you know and are comfortable with. The first carb i had was an Edelbrock but it soon went away for a quadrajet (on a Jeep with a 350) Since then i have always used a Qjet or Holley

boy oh boy, i get to disagree with royce this time?

A carb is a hole that mixes 12 to 15 parts of air with one part of fuel. As long as you can tune it to do that, it's doing it's job and will perform equally with any other device the same size doing the same job and tuned just as well.

I've been a holley guy since before I got my drivers license, until I bought this car that had an Edelbrock on it. It was there, and ran terrible, so I had to learn how to tune it.

Ede's are terribly easy to tune.

You can do the equivalent of changing primary mains AND power valve AND power valve channel restrictions in 2 minutes with a small phillips screwdriver only, don't even have to take the top off the carb. You can take the top off the carb in 3 minutes or less and change all 4 jets without spilling a drop of fuel.

Properly tuned, they run great. Ask Tokyo Torquer, he runs a pair on top of an 8-71.

Hate to even say it, but if I buy another carb for this car (will only happen if I cannot budget EFI) that carb will be an ede 750 AVS. Mostly because I've got $150 invested in plumbing for it.

The Edelbrocks use a metering rod system which usually does better for emissions and fuel mpg. I like the Holleys which are supported with all kinds of goodies. I think Holleys are more prone to need attention. Power valves do go out. Needle and seats stick. That's from years of my Ford Dealership and all the trucks that I had to repair. This topic could be debated for ever.

If decide Holley, then think about the, somewhat more difficult to tune, but really sharp looking Demon

I've never been into a Holley carb. so they're still a mystery to me. But I have been into an Edelbrock/Carter carb. Once I got ahold of a Ebrock manual and a tuning kit, it's fairly easy.

I had to learn about my Edelbrock because I got mine "rebuilt" from a high volume carb. rebuilder on ebay. (big mistake...:clonk: ) I found the floats were over 1" out of adjustment, the main jets were 2 stages rich, the metering rods were unknown because someone buffed the ID numbers off with a wire wheel , the step-up springs were wrong & the secondary jets were 1 stage rich.
Turns out my "rebuilt" carb. was basically just cleaned up & had new gaskets installed.

On the positive side, my car runs MUCH better now & I got to learn about Ebrock carbs. :thumbsup:

New Edelbrock 750 performer on my most recent first gen when I bought it in June. It's coming off for an 830 Holley this winter. Enough said.

Jim,
While you are kind of right, there is MANY differences in fuel metering. Size is not the only thing that matters. There are design differences and the Edelbrocks can not hang with a Holley of equal size if both are tuned to their best. Even Mr. Edelbrock ran holleys on his race car (as well as the current Edelbrock sponsored or owned race cars, last time I checked).

Me and Mike (Tokyo) discussed carbs quite a bit and he was sold on his Edelbrocks even though I didn't agree. Last I heard he was shopping for a pair of Holleys. Call 10 Blower shops and I am willing to bet 10 out of 10 will recommend Holleys over Edelbrocks. There is a difference, Edelbrocks are not good blower carbs. Can you make them work? Sure. Will they ever work as well as Holleys in that application? No way, no how. I personally had a guy with a blower engine running Edelbrocks come up to me and ask why my car started and ran so much better than his. He paid me to come tune his car, after many hours of fighting with the Edelbrocks, I begged him to buy a set of Holley "blower" carbs. He did and within 30 minutes of me installing them his car had more power and started better than ever. He couldn't thank me enough. Sure I got the Edelbrocks to work better but, they didn't work like they should.

With your theory that all carbs of the same size will perform the same, why Are there companies like Quick Fuel, Pro Systems, All State Carbs, Barry Grant? They don't "tune" the carb for you, they modify it to atomize fuel better, which in turn gives you better performance and throttle response.

I will be willing to bet anyone that is willing to try to get an Edelbrock carb to out perform a Holley of the same size on a given performance engine. The test would be accross the power band. I can tell you the results would be the Holley would make more power and the Edelbrock would get better mileage. Prime example is Tokyo's blown engine, he was able to get great mileage with the Edelbrocks but, he is giving up power to do so.

I've tuned and ran a few Edelbrocks, they are not terrible carbs. For the right application they may even be better. For all out performance there is no contest. How many "aftermarket" performance shops modify and/or sell "race" Edelbrocks or Carters? Why do you think that is? They are cheaper, have less "moving" parts (if I remember right), they are easy to seal and are not nearly as leak prone as a Holley. Even with all those "advantages" go to any track in the country and every fast car will have a "Holley style" carb, you might see a Predator or two.

Edelbrocks are easy to get close/tune. For a beginner I would almost suggest them over a Holley, there is a lot less to learn and they are more forgiving. For a mild street application there is nothing wrong with them. When you are after all the possible performance, you have to step up to a "performance carb".

Once again I have went against one of my basic rules, which are to stay away from carb and cam threads. You don't have to agree with me and my feelings won't be hurt but, I challenge you to find a fast car let's say 11.50 or faster N/A that is running an Edelbrock, you will find a Q-jet or two out there.

Maybe we should start a poll here?

The current Edelbrocks on my blower motor are the first I ever had. In the past I had 1 Demon and many Holleys which always worked fine except for the minor fuel leaks which would stain the intake manifold and the occasional stuck float when going over a big up and down bump (solved with a rap on the float bowl with a screw driver). I decided to try the Edelbrocks for the following reasons; no leaks, easy to tune and replace jets without spilling fuel on engine and I much prefer the simplicity of running an inline throttle linkage as I do not appreciate the looks of all that linkage hanging on the side of the blower or the complicated function of a side-saddle linkage. At 1/2 to 1/3 the price of the Holleys, they were cheap enough to give a try and maybe switch to the Holleys later. When I first opened the box, I was a bit disappointed in the quality of the moving parts, but having tried them, I must now say they dam work well in spite of their simplicity. My carbs are totally reworked though, with drilled out Jets, bigger needles/ seats, bigger accelerator pump, choke plate removed, etc... But they were easy changes. I would also like to point out that I consider my 750 edelbrocks only equivalent to 650cfm Holleys, at most, the size Holleys I would run if I went that route.

The experience with the Edelbrocks have been very good and I have an Innovate wide band AFR to ensure I am getting the right fuel curve. They do the job. I think the spinning rotors in the blower probably help atomize the the fuel even more before it gets to the cylinders, so mayube less critical than with an NA motor. I get about 18mpg and I have more power than even my 10" MT ET Drag Slicks seem to be able to handle. However, I am constantly being told I would make much more power with the Holleys. This question has been eating at me as inquiring minds want to know. My blower shop is hounding me to buy a set of Holley blower carbs saying he has seen an easy 30 more horse with the Holleys on blown SBCs, but at $1600 for the pair, I am sure his margin is sweet.

Although I am happy with the Edelbrocks, I really want to try the Holleys and answer the nagging question once and for all. I have seen a few cars running high 10's and several in eleven's with a single Edelbrock 750 and I have a pair of them and my goal is only 11.5's with stiff street suspension and a manual transmission. I was hoping to go to the track to see if I could reach my goals with the Edelbrocks this Fall, but broke my shoulder racing motocross 3 weeks ago, so it looks like I will have to wait till next Spring as I cant change tires with the shoulder.

Just because all the racers/ race shops use Holleys doesn't necessarily mean that a street car with moderate cfm requirements will be hugely compromised, but a clear answer to that question remains illusive. Even with Holleys, they almost always use mechanical secondaries even for a street car and that just doesnt make sense to me. So just because most people do it doesn't mean it is the definite way to go. Many moons ago, I had a blown SBC with 2 650 DPs/ mechanical secondaries that worked fine but was a gas pig at 7 or so mpg no matter how I tried to stay out of the secondaries. One carb was sourced from a friend and was not quite the same color as the other so I wanted a matching pair and bought a pair of new Holley 650 VS carbs. I was astounded at the improvement in gas mileage, improving to ~15mpg with the same great power as before with no discernable loss. If I get a set of Holley blower cabs for my current motor, I am thinking of VS with the small fuel bowls so I can run them inline, and not follow the band wagon.

we all have our opinions, and are entitled to them. Personally, I do prefer a Holley, always have always will. I'm just not gonna spend $300 to replace a perfectly adequate fuel mixer on a mild street car.

I will give you this tho....

If one carb is giving better mileage than another, then one carb is running rich. This happens a lot with Holleys, because the primary mixture is controlled only by the primary mains at part throttle (vac above the # on the power valve), and by the mains plus the power valve channel restrictions once the manifold vacaum is below the # on the power valve. Since few tune by jetting for part throttle and drilling PVCR's for "power valve open" conditions, the part throttle mixture on a holley is usually rich, hence the bad mileage. While it is possible to fix this, and make your holley gat mileage as good as an ede, you need some drill bits to do it.

If one carb produces more power than another brand same size carb, then either the manufacturers used different specs to rate the airflow (the carbs are not REALLY the same size, or one carb is atomizing the fuel better than the other and producing a cleaner burn.

One thing to consider is that the biggest Edelbrock carb you can get is 800 cfm. Holleys can be had as big as 1350.

On the Holley you have near infinite adjustability with the accel pump circuits (not on an Eddy) and more adjustability in the idle circuits (interchangeable IFRs). With an HP style Holley you have a lot more that you can do to improve parts of the fuel curve under certain throttle conditions then an Eddy -- by far.

There is much more to a carb than just mixing air and fuel at the right ratio. Emulsion characterics are another thing to consider. On the Holley Ultra series carbs (or if you are handy with a tap and drill) the emulsion holes can be tweeked to adjust certain parts of the RPM band. The emulsion "package" is what the aftermarket Holley-like carb companies typically go after for improved performance (Demon, Pro Systems, Bigs, etc). They all use Holley-type carbs because you just can't change these things on an Edlbrock like you can a Holley.

That being said, there is nothing wrong with the Edlebrock carbs. They are great if you have a "street rod" that is not after the absolute last ounce of HP -- especially if you have no interest in tuning or want to keep it real simple.

Just a few thoughts.

Any one have any experience with an edelbrock on a track day or autocross car? Some things I have heard say the edelbrocks like to stall on hard turns and the holleys like to stall under hard braking. Any experience out there. I am not looking for the highest horsepower but more for driveability issues. This is a mild street motor that won't see a drag strip unless the autocross happens to be running there that day.

I've done Autocross with a Holley and drag raced with an eddy. No problems with either . . . maybe I just don't go fast enough. :)

I have a theory about folks that bash Holleys (or other carbs for that matter). There are so many adjustments you can make, that if you don't go about it correctly, you can find yourself way off in the weeds. Take jets for example. Countless times you hear people wanting to change the jets on a new carb without having fixed the basic stuff like the choke, acc pump, or idle setup. To see what I mean try searching threads for the keyword "Jets". There are over 300 threads in the results and I bet more than 1/2 of them had issues that weren't jet related. My advice would be that whatever carb you go with, get to know it well and be sure you make adjustments in a logical order. Changing jets (or metering rods) rarely is the first step as most carbs generally are very close to right on with the baseline specs.

Any one have any experience with an edelbrock on a track day or autocross car? Some things I have heard say the edelbrocks like to stall on hard turns and the holleys like to stall under hard braking. Any experience out there. I am not looking for the highest horsepower but more for driveability issues. This is a mild street motor that won't see a drag strip unless the autocross happens to be running there that day.
i have stalled with an edelbrock a few times on hardturns. never with a holley they do better on turns... or so i hear.

If one carb is giving better mileage than another, then one carb is running rich. This happens a lot with Holleys, because the primary mixture is controlled only by the primary mains at part throttle (vac above the # on the power valve), and by the mains plus the power valve channel restrictions once the manifold vacaum is below the # on the power valve. Since few tune by jetting for part throttle and drilling PVCR's for "power valve open" conditions, the part throttle mixture on a holley is usually rich, hence the bad mileage. While it is possible to fix this, and make your holley gat mileage as good as an ede, you need some drill bits to do it.


Jim, there is more to cruise mixture then jet size and PVCR with a Holley. The IFR size effects cruise mixture more than the jet -- especially at lower RPMs and light loads.

Picture a graph with 100% of the available A/F mixture coming from the IFR and low speed bleed (they work as a matched pair) at idle and near 0% of the A/F mixture coming from the IFR and low speed bleed at red line. Now picture a line that runs the opposite way with A/F mix from the main jet and high speed bleed -- 0% at idle and near 100% at red line. The two circuits provide A/F mixture at part throttle with load and RPM effecting how much from each. The amount of AF provided by each circuit is cumulative throughout the RPM range.

The Edelbrock accomplishes pretty much the same thing with bleeds and jets, except that the power valve and PVCR is replaced by a metering rod, hanger, and spring. Same basic thing except the Holley is nearly infinitely adjustable with whatever PV, PVCR, and main jet you want to use where with an Eddy you are limited to available metering rod/jet combos and available springs. I suppose either is accurate and adjustable enough for most combos . . . but personally I am more comfortable with the Holley.