I am looking into getting a new Carb for my Monte Carlo - it has a 350 crate installed and I can't decide if I should go with a Holley or Edelbrock. I have been debating with two people, both very knowledgable when it comes to engines and one recommends the Holley Double Pumper, and the other (who is doing the work on my car) recommends an Edelbrock.

Just looking for people to chime in with their experiences / recommendations and why?

Thanks

 

I seem to have had better luck with the Holley on GM motors that I've had in the past.....never could seem to get the edelbrock tuned just right and was always fighting with them. Now on Fords.....I've had better luck with Edelbrock. So for a GM motor I would recommened Holley, but I'm no where close to being a mechanic....that's just from personal experience!


~Nick

 

holley. no doubt.

 

Get the one your mechanic likes if you expect him to tune it.

I'm partial the the Q-jet for a mild street car. Great fuel economy if you keep your foot out of those monster secondaries.

 

Is it a daily driver?

If you are thinking of the Edelbrock Spreadbore carb (small primary & very large secondaries) that is like the old GM Rochester spreadbore. I say they work great and are tunable via different metering rods etc. A Holley double pumper etc. may give you issues if it sits a long time (gasket shrinkage ie; seapage) or even issues with cold start (blowing power valves) if the choke is not adjusted just right or if a good starting sequence is not used and a lean condition backfire occurs.

What usually happens is an engine will be built using headers an/or deletion of the heatriser / intake crossover heating that helps the engine / manifold warm up. And then a manually choke Holley will be used and on a cold start the engine is accelerated before it can properly take the load and..........Pop! backfire and a blown power valve. Then the carb runs rich and will not perform to it's potential.

If you want to install it adjust the choke and drive it with minimum tweaking and great cold starts and better mileage than a holley. Install the spreadbore Edelbrock they are 800cfm+ and work great.

If you like to tinker and want it to have that usual hotrod "It's got a Holley look" put on the double pumper and have fun.

Without a crossover on the intake or heatriser the intake does not heat up as fast as when stock. The cold intake acts like a sponge (like your hot water line on the farthest sink from the water heater in your house)and does not allow the air/fuel mixture to atomize properly to power the engine well when cold. This is why it is lean when cold and need to be richened (choked) properly.

 

First off - thanks for the replies. Second, this is not a daily driver - it is my third car and is garage kept. However, I have no plans of trying to make this a drag car, I plan to drive it to work occassionally when the weather is nice and maybe take it to the local drag strip every now and then just to have fun, legally. Drive on the weekends in summer and such... This is the main reason I am leaning towards the Edelbrock - if I was trying to build a purely drag car, then I believe it would be the Holley hands down, since I feel tuned right you can get better performance out of the double pumper. It won't get driven much in cold weather, so I am not sure if I will have the cold start trouble mentioned - or will I? Thanks again for the replies and keep them coming.

 

I've had really good luck with Quadrajets. I use to run custom built q-jets all the time that were opened up to 850 cfm and larger. I use to get mine from the Carb Shop. They were super stock carbs but I'm not sure if they still build good stuff or not. I ran a big block Buick in a 71 Skylark that ran consistent 12. teens with a stock piston engine through the exhaust with a mild cam and still ran an electric choke on the Q-jet. The carb worked great for daily driveability and would 60 foot really well with that carb as well.

 

Ever think about the demons? the ole boy i bought my TA off of builds cars (32 roadster and two HIGH hp corvettes) and he perfers the demons.

That being said, all i have personal experience with is the q jet. which is on my TA. my '57 is fuel injected and then theres my dodge.

 

Have you thought about trying the Holley 3310? It is a 750 cfm but has vacuum secondaries like the Q-jet. I do not prefer the double pumpers unless I am racing a bracket car(double pumpers do seem to be a little more consistant run to run when racing). In my experience, the carbs with vacuum secondaries seem to out perform the double pumpers in most situations except maybe all out drag cars.

I believe that now when you buy a Holley carb, they have the check valve built in to protect the accelerator pump in case of a backfire. If not, you can buy a kit to install one pretty cheap.

Also, parts are available everywhere for the Holleys without having to buy a whole rebuild kit. You can upgrade to the blue teflon coated gaskets and you wont have the problem with the bowl gaskets sticking and tearing when you disassemble them.

I have dealt with the Edelbrock carbs and they are good but I still think the Holley is more simple and easier to find parts for locally.

Just my opinion

David

 

From experience in this one. Go with the edelbrock for ease of tuning and reliability. I used Holley extensively on my gasser engines, and they would "holley" ever stay in tune, forever fiddling with them.

Made the switch to Carter AFB, which is really apples to oranges, but no tuning problems, set them up, and they run, every time, no problem.

Edelbrock offers either the Q-jet style, which I have had good luck with, or the rebadged AFB carb, which is also an excellent choice, especially for a car that is not driven every day, and only for pleasure. I no longer find pleasure in having to tune something every time I drive it.

Good luck, and I would go with what the mechanic / tuner recommends

 

I've run and like both. Both have good and bad points to them. Overall reliability and "tune it and forget it" goes to the Edelbrock. Performance and tuning capability goes to the Holley. I had a 750 manual choke Holley on my Blazer when it was -25* out. My parents fuel injected vehicles wouldn't even think about starting and the good ol' Blazer fired right up (after cranking and pumping the pedal awhile). Either carb properly tuned and set up right will be a good choice.

 

Edelbrock forsure.
A lot more dependable imo, and easier to tune.

I would also not look past Demons.

 

OK, I'm gathering this is a street car with a 350 crate engine (mild hp, smooth idle).

Keep in mind that the Edelbrock is just a Carter AFB in different clothing. Same metering system, same basics of operation. Yes, it's tuneable, but not NEARLY as versatile or tunable as a Holley.

Most people have a love/hate relationship with Holleys. They are very tunable, but tend to be finicky.

So why not get all the benefits of a Holley without the Headaches?

All you need to know about street carbs is this:
ROAD DEMON by Barry Grant

IMO, they are simply the best all-around carbs for a street-driven vehicle with mild cam, compression, and other factors.


Some other thoughts on carbs:

1) Ensure you have manifold heat to a street-driven car. In other words, no "air gap" style intakes. Yes, the air gaps make 10-15 more hp or so, but the non-gap intakes are MUCH better in cooler weather, and delivery superior mpg-- and mpg is really important in a street car.

2) You can use a MUCH MUCH larger carb on a typical dual-plane intake manifold than you'd think you need. This is because rather than being able to draw on all 4 carb barrels, a cylinder basically "sees" only half of the carb. Thus, even a mild street 350 can effectively use a carb in the 850-950 CFM range with a dual plane intake (like an Ed Performer or Performer RPM). The same engine with a single plane (open plenum) intake should use a much smaller carb in the 600-650CFM range. You'll be much happier with the bigger carb on the dual plane intake-- more bottom end, much higher vacuum and better mpg.

3) Don't buy the standard cheapo Holleys. The reason Holleys get a bad rap is because people are talking about the cheapie 0-1850 (650) and 0-3310 (750cfm) models. These are "universal" calibrations, which mean that they don't work well on any engine at all. The boosters are old design, the air bleeds aren't tuneable, they often don't even have emulsion wells, never mind tuneable ones. They are very crude carbs (just like the AFB/Ed carbs!) that are basically just glorified fuel leaks. The MINIMUM level of Holley I would even consider is a 4150 HP Street (0-82750). This is a great all around carb, with tuneable bleeds, PV protection, modern downleg boosters, etc.

4) Always buy vacuum secondary carbs. The idea that a double pumper makes more power is mostly myth. A properly-tuned and sized vac sec carb is far more versatile and more powerful because it allows you to run a bigger carb. The same intake and engine that needs a 650 double pumper can go with a 750 with vacuum secondaries.
As for spread-bore vs square bore, stick with square bore. The spread bore carbs (Carter ThermoQuad and Rochester Quadrajet) are old and lack in features. A "brand new" Q-jet is just a rebuild using old tech, and tuning and replacement parts are unnecessarily difficult. Yes, small primaries and big secondaries is a great idea-- only no one is doing it with modern technology, and going this route limits manifold selection or forces you to run an adapter/spacer which might cause hood clearance issues.

5) The best Holleys don't say Holley on them at all, though they use the same tuning parts. The best Holleys come from Demon (barry grant) AEM, and Braswell Carburetion. A well tuned modern carb can rival the best EFI systems in performance and efficiency-- but they decades-old cheapo carbs like the universal Holleys and Edelbrocks are NOT in this group!


The perfect carb for your needs is a Demon "Road Demon 725". You can do better, but it will cost more.