Edelbrock or Holley?
Thread Starter
Racer
Joined: Apr 2007
Posts: 492
Likes: 3
From: Temecula CA
Edelbrock or Holley?
I've read alot of threads, and I know that most forum members are q-jet fans, but I am contemplating a change to either an Edelbrock Performer or a Holley Street Avenger. I have a 350 cid, 290 horse GM crate motor with a Performer manifold and headers, running through a 4-speed. Any words of wisdom about my two options?
Instructor
Joined: Aug 2007
Posts: 116
Likes: 0
From: Temple TX
I am using a Holley SA 670. I am completely happy with it. I have no hesitation what so ever and I only had to play with the mixture alittle bit right out of the box. I am running a 350 with heads/cam swap. Hope this helps.
Advanced
Joined: Jul 2007
Posts: 75
Likes: 0
From: texas
i have the holley SA 770 w/ electric choke on a '69 350/350 4 speed w/ cam, heads, hooker long tubes. The intake is a real old first gen edelbrock torker. i nixed the vacuum adv. distributor and went with a mallory unlite mech. adv.. only problems i've had are the throttle cable setup, but i'm waiting on parts from jegs to fix that. drove 70 miles yesterday no problems other than the darn cable bracket. all my car buds say they think it runs either "rich" or "fat" <= (still havn't figured out what that means). i've had the holley jey kit for quite a while and have hesitated changing them until i get the cable situation sorted out and then move forward from there. other than that, the only comment i have is that the choke is finicky. but this is my first old car so i don't think that means anything.
Advanced
Joined: Jul 2007
Posts: 75
Likes: 0
From: texas
after posting my previous reply my curiousity got the better of me and i went out and inspected the 2 carbs for my car. one is a holley 4778/750 in almost new condition and the one on the car is a SA 770. the fit/fuction of the mechanisms are way different. the 4778 with mech. secondary functions way bettter than than the SA. the springs on the 4778 are thicker wire diamter, everything lines up correctly, etc. whats the deal?
Thread Starter
Racer
Joined: Apr 2007
Posts: 492
Likes: 3
From: Temecula CA
Thanks for the input, Fellas. I burned the midnight oil last night researching some old posts. I am an old school guy, so I would love to use an old q-jet, but I believe mine is FUBAR from a previous incompetent rebuild. It looks like the newer carbs are easier for a relative novice to work on (another plus). I thought the Barry Grant carbs are "too much" for my mild engine. Any thoughts?
Temvette72
Temvette72
Instructor
Joined: Jul 2007
Posts: 106
Likes: 0
From: Brampton Ontario
I just picked up a AED 850 for the 427 build.
Seems it a tricked out Holley Body. Hmm!
http://www.aedperformance.com/
Seems it a tricked out Holley Body. Hmm!
http://www.aedperformance.com/
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Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
For a street only car, I prefer the Edelbrock...simple to adjust and it holds its adjustments, plus it will likely run a bit smoother and better fuel economy. If you want street/strip performance, get the Holley or better yet, a Demon.
Instructor
Joined: Sep 2007
Posts: 126
Likes: 0
From: Dallas Texas
Holley Holley Holley - but - you cant run it straight out of the box - depending what mods you have done to your engine etc, you really need to take a vacuum reading at idle and make sure you have the appropriate power valves in the metering blocks and jet the carb correctly. If you can smell fuel in your exhaust at idle then your power valves are too high. The difference is like night and day - both in performance and fuel economy. With the edelbrock you also have to change the metering rods and from personal experience I just dont think you get as good a performance from it than what you get with the Holley. That's my 2 cents.
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
no a barry grant would not be too much for your engine. there are all kinds of sizes to choose from thats why i thought the 650 road demon would suit you perfect. they are totally trouble free . all you do is bolt it down , set your float height . set your idle and maybe your mixture but that is normally set pretty close out of the box.... when you buy the carb you get an awesome dvd with it that explains how to do all this and its really easy and clear.here is my demon.
Melting Slicks
Joined: May 2006
Posts: 2,369
Likes: 103
From: Centerville Louisiana
Holley Holley Holley - but - you cant run it straight out of the box - depending what mods you have done to your engine etc, you really need to take a vacuum reading at idle and make sure you have the appropriate power valves in the metering blocks and jet the carb correctly. If you can smell fuel in your exhaust at idle then your power valves are too high. The difference is like night and day - both in performance and fuel economy. With the edelbrock you also have to change the metering rods and from personal experience I just dont think you get as good a performance from it than what you get with the Holley. That's my 2 cents.
Intermediate
Joined: Mar 2006
Posts: 42
Likes: 0
From: PENDERGRASS GA
I second a demon carb, I ran a Road Demon 625 and it was the fastest and hardest pulling of any carb that i had on my 72 350/4speed, faster that a raped ape, I ran holley and edelbrock before the demon
Race Director
Joined: Jun 2000
Posts: 10,046
Likes: 675
From: FL
My only comment is that I am amazed to hear people call the Edelbrock Performer a newer design carb. It is just a rebadged Carter AFB designed back in the 1950's. The only true new carb design in the last 20 years is the Demon line and they are still based on the Holleys that go back to the 60's.
Instructor
Joined: Feb 2006
Posts: 144
Likes: 0
Only had trouble and bad experience with DEMON CARBS, and i have had quite a few of them in my hands.
the most common problem i have had is that i cannot get them to idle low enough, but problems with foreign objects inside the carb, loose screws all over, wrong alligned gaskets, play in the butterfly axles etc are seen frequently.
I belive Summit discontinued Demon carbs more than a year ago because of to many failures.
For me the choise is between Holley and Edelbrock, i have had a couple of Edelbrock fail and a single holley in my lifetime (out of 50+ carbs)
and i tend to use edelbrock for the stock engines and holley DP for street/strip.
For race carbs and best reliabillity/performance on the street i reccomend AED carbs, that are based on the HOlley carb.
the most common problem i have had is that i cannot get them to idle low enough, but problems with foreign objects inside the carb, loose screws all over, wrong alligned gaskets, play in the butterfly axles etc are seen frequently.
I belive Summit discontinued Demon carbs more than a year ago because of to many failures.
For me the choise is between Holley and Edelbrock, i have had a couple of Edelbrock fail and a single holley in my lifetime (out of 50+ carbs)
and i tend to use edelbrock for the stock engines and holley DP for street/strip.
For race carbs and best reliabillity/performance on the street i reccomend AED carbs, that are based on the HOlley carb.
Drifting
Joined: Oct 2007
Posts: 1,458
Likes: 1
From: Collinsville MS
St. Jude Donor '08
If you want to take it out of the box, bolt it on and make some minor adjustments and drive it and forget about it, go with the Edelbrock. If you like to tinker with it constantly everytime you make a mod, get the Holley. I have both on two 78's, both with 350s. The Edelbrock I never have to fool with. The Holley is a constant battle but it definitely has a better response. I am still learning on the Holleys..... just my .02
Instructor
Joined: Sep 2007
Posts: 126
Likes: 0
From: Dallas Texas
at idle take a vacuum reading and then halve it and stick a zero on the end - that is the maximum power valve you want in the back. So if your vac at idle is 10 "Hg then you want a maximum of a #45 or even drop to a #35 power valve.
Instructor
Joined: Sep 2007
Posts: 126
Likes: 0
From: Dallas Texas
here you go - this is from the Holley website and might explain the power valve thing a little more clearly........
POWER VALVES:
The number stamped on a power valve, such as a 65, indicates the manifold vacuum below which the power valve is
operational. In this case, all manifold vacuums below 6.5” Hg, the power valve is operating. Generally a 65 power valve is
sufficient for most high performance applications that have a manifold vacuum of 12” Hg or higher. However, some problems
can result with radically cammed, full-race machines equipped with automatic transmissions. These vehicles often “idle” at 2000
rpm, approx. 6.0” Hg. At this point, the main nozzles are starting to feed and richen the mixture (supplied by the power valve)
and the engine will probably “load up”. To correct this problem, install a 45 or 35 power valve. If the engine has a manifold
vacuum of 12” Hg or less, a good way to determine power valve size is to take the manifold vacuum at idle and divide that
number by two. The answer is the power valve size. This will provide idling and proper fuel flow under wide-open throttle
conditions when the manifold vacuums seldom rise above 1” Hg.
hope this helps.
POWER VALVES:
The number stamped on a power valve, such as a 65, indicates the manifold vacuum below which the power valve is
operational. In this case, all manifold vacuums below 6.5” Hg, the power valve is operating. Generally a 65 power valve is
sufficient for most high performance applications that have a manifold vacuum of 12” Hg or higher. However, some problems
can result with radically cammed, full-race machines equipped with automatic transmissions. These vehicles often “idle” at 2000
rpm, approx. 6.0” Hg. At this point, the main nozzles are starting to feed and richen the mixture (supplied by the power valve)
and the engine will probably “load up”. To correct this problem, install a 45 or 35 power valve. If the engine has a manifold
vacuum of 12” Hg or less, a good way to determine power valve size is to take the manifold vacuum at idle and divide that
number by two. The answer is the power valve size. This will provide idling and proper fuel flow under wide-open throttle
conditions when the manifold vacuums seldom rise above 1” Hg.
hope this helps.
