Holley 600 vs Edelbrock 600 for fuel economy

Simple question, which is the better carb for fuel economy on a Chevy 350 with a mild cam and double hump heads, a 600 Holley (4160) or a 600 Edelbrock? Maximum performance is not an issue, just better fuel economy.


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Simple answer. A QuadraJet.

After that a 390 Holley List 8007 or a 500 Performer. The primaries are just to big on the 600's for optimum fuel economy. The'll do OK but I just switched from a Holley 6619 that had been tuned to death to try to get better mileage on a 318 Dodge 1/2 ton to a junkyard Q-Jet and picked up 2 MPG. All I did was bolt the Q-Jet on and set the mixture screws by "ear".

From what I have read from experience the Edelbrock will give you somewhat better fuel mileage. I have used both carbs on my truck and there was not that much difference mileage wise but for throttle response the Holley will out do the Edelbrock carb.

On the Edelbrock carb if you look at it the primary barrels they are smaller then the secondary's. It is kind of similar to a quadrajet but much simpler to tune and less parts.
If you want simple and for a stock motor the Edelbrock is easy to tune. If you want a little more throttle response and more ways to tune it then the holley is your best bet. I rebuilt a holley 1850 model carb for my brother on his chevy 305 and he loves it. My dad put one on his ford 302 and it ran like a charm and he gets almost 20 mpg with his setup.
Eric

Quadrajets are probably the best in this case, but will they function alright with a mild cam as tuning parts for them are not readily available?

If you go to summit or jegs they sell rebuilt quadrajets for different horsepower ranges. Summit right now has brand new quadrajets under there brand name for 300 bucks which is a great buy if you want to go that route. You can still also get metering rods from them to fine tune your carb if need be. Give them a call and they should be able to hook you up with something. If that is the main thing you want is the best fuel mileage then the quadrajet will do the best job in that part.
Eric

I don't know about Quadrajets and never ran one. Anyhow, the question wasn't about Quadrajets but Edelbrock versus Holley. The key is to get the correct CFM carb, whether its Edelbrock or Holley. Most people who want the mileage and reliability of daily use, go with the Edelbrock and tend to run a smaller CFM carb. The Holley guys go with Holley's for performance reasons and have options of vacuum secondaries or double pumpers which manually come on without the need of vacuum from the engine. I agree with Eric32 that when I ran the Edelbrock 600 CFM, my performance wasn't great, but I did get better mileage. Since, the carb is on a street rod, and I prefer performance from my engine, I went with the Holley 600 CFM double pumper. Big difference in performance. The mileage is not as good, especially if you put your foot in into it. So my recommendation is to use the Edelbrock when your cruising or going long distance. For the street races or local cruise nights, pop the Holley on.

For optimum performance out of the box go with a holley, for optimum milage out of the box go with edelbrock, from wide parts selection- holley, for easy of rebuild and tune go edelbrock, for the best of everything except price get a custom carb built from a very well known carb shop.

As mentioned, you want MPG you go Quadrajet. No contest.

You shouldn't have any problems getting tuning parts for Quadrajets. Try Cliff's High Performance Quadrajets.

I've also bought Q-jet parts from Edelbrock. They made Quadrajets for a while; they've still got a few for sale on their online store. They still make and sell parts for them.

If economy is your goal, you're not going to do any better than a Quadrajet as that was the goal GM had in mind when they engineered it. So if you've got a spreadbore manifold that's the way to go.

As far as the difference between a Holley and an Edelbrock, I don't believe there will be a huge difference in fuel consumption between the two.

I'm guessing the manifold choice was the reasoning behind the original question, and there's about a 10-15% difference in mileage usually.

That's what I thought when I read the original post, but then he came back and asked about Quadrajet parts.

Also, I've never noticed much of a difference in terms of economy between Holleys and Edelbrocks. Carters, actually, as I've never owned an Edelbrock.

But, as the saying goes, your mileage may vary.

I've owned and ran both on the same cars. The holley can be tuned for equal milage but the edelbrock is better out of the box. The main reason for this I assume is earlier secondary openings on the Holley. The secondary opening on an Edelbrock is unique and really a more user friendly design IMO. Not as easily adjusted but more user friendly out of the box.

Qjets have TONS of aftermarket parts for tuning. Up to about 600 hp they are easily modded. After that, if you're looking for MPG, you're barking up the wrong tree

Edelbrock tends to return a little better mileage than Holley.

The reason for the original post was I have a 4160 Holley on a 350 with a mild cam and double hump heads that is getting some real bad fuel economy. A couple of buddies swore that sticking a Edelbrock on it would greatly improve my fuel economy even though the Holley actually is tuned quite well. I have a dual pattern Weiand intake and would go Quadrajet if I could make it work with the cam. A new, less radical motor is in the works so I'd like the carb I choose to work on that as well when the time comes.

Guess I haven't read the "rules" for awhile, I wasn't aware we had to stick to the choices given even if they aren't necessarily the best ones. I'm pretty sure I'll do it again though, just a born troublemaker I guess.

As far as QuadraJets......... try it you'll like it. They can be a PITA to get dialed in but once you do the only thing better is EFI and it doesn't have that cool wailing sound at WOT.