Opinions on carbs

[dan468]

I need help choosing a carb for my 72 pickup. it's a 454, aluminum oval port heads from chevy performance with the 219 188 stainless valves, 9.7:1 compression, eddy air gap intake, and cam specs are duration @ .050 intake 229 exhaust 237 lift is intake .563 exhaust .585 at 110 degress centerline. (cam is hydraulic roller)

Thanks!!
Dan in AZ

[hchad18]

I've not had any problems with edelbrocks, but I also have a Demon thats on my 540 (way to small) that seems to be a pretty good carb. Never had any luck in my world with Holleys. On jegs website it lists the demon carbs and what engine they go well with.

[dan468]

what kind of CFM do you think I should be using?

[bryanw1968]

I'd go with a 750VS speed demon. I'm running a 650DP speed demon and love it. Barry Grant under specs their carbs. My 650 actually flows more like 720CFM. Holley's are great if you like to work on carbs, a lot. I know edelbrocks are great maintenance free semi-performance carbs. If you're seriously considering going with a demon go jegs and look at the application chart. The fit carbs by displacement and cam size.

Good luck,
BW

[cooters]

3310 holley 750 vac secondary is a nice carb

[Farmstore34]

I'm a big fan of the Edelbrock carbs. There simple, reliable, and relatively trouble free. Holleys are good but require too much attention for me (and a pain to overhaul).

[brak]

If you want a carb that's easy to set up, very low maintenence, good for everday driving, a 750cfm edelbrock would be the way to go for your engine/intake combo.

if you are looking for a hi performance setup, and don't care about fuel economy, a holley 750-800 cfm carb (maybe a double pumper) would be a good choice. although they require significant adjustment, and tuning to get them running exactly how you want.

[RACINJASON22]

This one will probably get as many opinions as what color shirt are you wearing. for instance.

hchad18-I've not had any problems with edelbrocks, but I also have a Demon thats on my 540 (way to small) that seems to be a pretty good carb. Never had any luck in my world with Holleys. On jegs website it lists the demon carbs and what engine they go well with.

I agree with the edlbrock statement but personally don't like the demon line Bad experiences.

bryanw1968-I know edelbrocks are great maintenance free semi-performance carbs. If you're seriously considering going with a demon go jegs and look at the application chart. The fit carbs by displacement and cam size.

You will have some tell you that edelbrock is way more than a semi-performance carb, myself included. I agree if you go Demon go with Jeg's GR8 coustomer service if you run into problems with the carb.

Farmstore34-Holleys are good but require too much attention for me (and a pain to overhaul).

In my opinion Holleys are the easiest carb to tune and by far the easiest to overhaul. Just me but thats were my experience is.

Personally I like Holley I would go in the 750 to 800 range for you application. I would never buy a Demon (as stated before BAD experiences) Edelbrocks are GR8 I have used them in the past with no problems just like Holley more.

IMHO if you don't know alot about tuning carbs and don't have a brand loyalty. Buy what your tuner/mechanic or whom ever will give you a hand on your truck suggests. As they will have a preferance and hopefully know about said carb choice.

I don't want to discourage you in any way or make others upset but opinions are based on experiances good or bad. Thats more than likely the reason alot of us drive chevys instead of ferds.

[martinkh]

Holley's require that you keep a screwdriver handy.
Edelbrock has mechanical secondaries.
Q-jets are super reliable.
I have 2 fairly new edelbrocks, one is a 600cfm for sure, dunno about the other one. After my engine swap, I would love to trade for a like-new 650 Q-jet.
But people have different ideas of "perfect"

[bryanw1968]

I'm surprised there aren't more Barry Grant fans out there?
I will tell you though, the first one I bought was NOT right for my application and my truck ran like ca ca. Each type of BG is designed for a specific application. Holley's and Edelbrocks are much more tunable/adaptable carbs across the board. Both are good carbs, not slamming either one.

I just personally like how BG's are made. Billet base plate, billet metering block, 4 corner idle adjustment....etc. Here is an example in case anyone was wondering what the application chart looked like.

http://www.jegs.com/instructions/132/Demon.html

[RACINJASON22]

I'm surprised there aren't more Barry Grant fans out there?

I think the design is wonderful the quality is just pore in my opinion. I for one was a GR8 fan of Barry Grant when they just built and modified original Holley's Some of the best carbs out there IMO. Some people have the best of luck with them as I see you are one of them. But there seems too be too many make it to the market that are just plain junk. The ratio good coments to bad just seems too high for me to give them another chance unless things start to sound a great deal better to me. Just my .02 RJ22

[bryanw1968]

Originally Posted by RACINJASON22

I think the design is wonderful the quality is just pore in my opinion. I for one was a GR8 fan of Barry Grant when they just built and modified original Holley's Some of the best carbs out there IMO. Some people have the best of luck with them as I see you are one of them. But there seems too be too many make it to the market that are just plain junk. The ratio good coments to bad just seems too high for me to give them another chance unless things start to sound a great deal better to me. Just my .02 RJ22

Which BG did you have and on what setup?

[onedayjake]

I have an 850 BG Speed Demon on the 454 in my 47 Chevy 1/2. I haven't driven it yet and I will probably dyno it first to tune it in as my friends have a Mustang dyno. I also have a 625 Road Demon on my 74 Jimmy and I am pleased with it so far.

[RACINJASON22]

This was back in 1998 on my first Vortec headed engine 625 Road Demon mild street engine in an 87 SS Monte Carlo 3.73 rear gear th400 from a 68 Chevelle full manual vavle body. The carb ran very good made good hp after adjusted on the car the problems were when the car was not running. Needle and seats never sealed always would bleed off into engine. Leaking bowl gaskets. I rebult this carb once completely trying to fix the problem areas to no avail. Had back apart trying different things nothing worked. Tech line well you might as well forget that. Like I said before the design is good the quality control in manufacturing is the problem IMO. There are many others like you that have had good experiences with them and I'm very glad for that. Just too many that have had bad ones IMO. RJ22

[jimmydean]

I run Carters on all my projects. Edelbrock's are rebadged Carters (that are rebadged Webbers). They are just plain easy to deal with. Ronco "set it and forget it" technology.

[stepside454]

Ive had a 770 Holley on my mild 454 for about 4 years now. I hear people saying you have to mess with them alot, I never touch mine.
Your 454 is a little healther than mine, I think Id run an Holley 800 DP on yours.

[mnunn454]

Originally Posted by RACINJASON22

I think the design is wonderful the quality is just pore in my opinion. I for one was a GR8 fan of Barry Grant when they just built and modified original Holley's Some of the best carbs out there IMO. Some people have the best of luck with them as I see you are one of them. But there seems too be too many make it to the market that are just plain junk. The ratio good coments to bad just seems too high for me to give them another chance unless things start to sound a great deal better to me. Just my .02 RJ22

Have a friend of mine that just took his BG Demon carb atop his 454 Vette to the dyno. 1st run was super lean. Pulled the jets and found one had a machining burr in it. That's just sloppy quality control. The guy picked up 100 horses by the end of the day (not all of that was attributable to the poor machining, but most of it was).

As for me, I have Holleys on my two rides. The 454 Elky has a Street avenger 770 CFM with vac secondaries and works flawlessly. Bought it new for about $380 I think. My truck's 454 has a 750 double pumper and after 4 rebuilds and $100-$200 in parts, it too runs flawlessly. I wouldn't swap either for an Edelbrock, but that's because they're "weekend warriers" and not "daily drivers".

I did try the 600 CFM Edelbrock on my truck and it was simple to adjust and fine for break-in, but too small for performance. I've heard good things about the Thunder AVS series Edelbrock carbs.

If I were doing all daily driving and could live with a little less performance, I'd go with a big Q-jet if it were new or recently rebuilt, or an Edelbrock 800 AVS.

[Rick Mills]

When I want a little more economy on my 454, I put on my Demon 670 vac. secondary. If I want a little more performance (weekends, etc.) I put on my Holley 800 D.P.
Jetted both for altitude and adjusted once... that's it.
Never have run an "Eddy".

[kxnomore]

Depends on what you're after, I guess. For performance the Holley 750 double pumper is a great carb. For ease of putting it on and forgetting about it, the Edelbrock 750 electric choke is a good choice. I've run both, and the Edelbrock is on my truck right now. It starts before the key is even completely turned and is soooooo smooth. Mileage was better too. If gas goes up any more, though, it will be back to the Quadrajet, I'm afraid.

[spdrcr29]

I watched the listing below and drooled and wished I had a built motor instead of stocker.....(sigh) Someday I'll get a 502 or 572, and when I do, it'll have a tricked out Q-jet on top.
http://cgi.ebay.com/ebaymotors/ws/eB...2902&rd=1&rd=1

[dan468]

Just got back on the computer today....Wanted to thank everyone for the input!! On the Demon site it recommends vaccum secondaries with auto trans. Does anyone know why? I have an old holley 850 DP I will probably just rebuild. I think that will at least get me to the store : )

[Tech @ BG]

Vacuum Secondary Operation:

The Vacuum Secondary Butterflies open based on the air velocity traveling past a hole in the primary venturi, as the air passes this hole it creates a pressure differential or vacuum in the vacuum pod. Based on the amount of vacuum in the pod, and the rate of the spring installed in the pod it controls the opening rate of the secondary butterflies. So engine RPM, and load will vary the secondary opening rate. What does this mean? If you’re running at a specific engine RPM, but have more load on the engine (going up or down hills, etc.) it will change how far your secondary butterflies are open at that point.

Changing the spring rate controls when the secondary butterflies will start to open, and at what RPM they will fully open. Having the secondary butterflies open later than optimal can increase fuel economy, but can hinder top end performance, and acceleration while having them open too soon can cause a bog or hesitation.

Vacuum secondary vs. Mechanical Secondary…

We find that cars with automatic transmissions with less than a 2800-RPM Stall Torque converter generally accelerate better, and give better drivability with vacuum secondary carburetor. If you’re running a loose converter or manual transmission a mechanical secondary carburetor will usually give you better throttle control.

Running a mechanical secondary carburetor on a vehicle with an automatic transmission and tight converter can cause drivability issues, as can running a vacuum secondary carburetor with a manual transmission or automatic with loose converter.

[gunnersm8]

ive run holleys forever. when i change the oil, i time and put the vac gage on it. thats it.
had an AFB once, it worked pretty good until it set my nova on fire. that was the end of that.
edelbrocks are good, kind of a PITA to rebuild, but how often does that come up?
the others are just different variations of the holley,so theres that.
my grandpa swears by quadrajets. but hes cheap and likes the smallish primaries. i dont know if you can get quadrajets anymore can you?

[Silveradobs]

I've had two BG 725 Street Demons and will never buy another-Went to a Proform 750 and it is way-way-way better. (406-dyno's @418hp)

[Psycho71]

Whatever you choose, you'll find someone who has had problems with it. There is no right choice in that aspect. Whatever you don't choose, will be the one everyone will say you should have gotten.

From reading A LOT of threads on carbs and dealing with a few myself, my take is this;

Holley; will require tuning to fit your application (the way it should be, to me), but will run like a striped ape when done right.

BG's; pretty, but almost the same as a holley in every other way. Seems like they had a better mouse trap when they started out, but now that mass production is necessary to keep up with demand, they require just as much tuning as a Holley will. In most cases.

Q-Jet; Get a good one, and your good to go, get a bad one, and you'll know it. But even with a good one, your giving up a little performance from either of the choices above.

Edlebrock; Performs about the same as the good q-junks (opps, I meant q-jet). Bolts on and go's, on just about any motor. Universal carb, for universal performance.



It really all depends on what you want to get into. I have had several Holleys over the years. All I'll buy (4150 or 4500 style). I've NEVER experienced ongoing tuning issues like some here talk about. Every one I've ever bolted on does require tuning, and sometimes even a call or two to their techline when I'm not thinking right. But all worked great after initial tuning, and rarely required tuning later. My present Holley (670 Street Avenger) required the expected tuning, and has been working fine for over a year (4seasons) now. The only reason I've taken the air cleaner off, is to change the filter element. But that alone can stretch some peoples abilities. I have even gone back months later to see if I could help anything by fine tuning it. Ended up with it set exactly where it was when I started.

With the motor specs you outlined, I'd put nothing but a Holley, or maybe a BG on it. Whatever the brand, it'd be a Holley based product. Go to your local dragstrip, or even dirttrack. Look at what these guys run. It sure aint q-junks (unless required by rules), and it aint Edle's. It's Holley based carbs. Be it Proform, Quickfuel, Holley, BG, etc. That ought to tell you something. But then again, these guys want all the power they can get. Why put $1,000's into a motor and then put some cookie cutter carb on it? You might get lucky and have the one in a million that is tuned properly for that particular application. But I aint that lucky. Therefore I tune my carbs to fit my application. And thus, feel confident I'm not leaving any HP/Torque on the table. Given that train of thought, buy the brand that is most condusive to tuning and has the most available parts. Then you'll get all the HP you paid for when you built that motor. And you might even learn more about Carbs, and how they function, in the process. If it's not a sin to learn something in the "short attention span/instant gratification" era that we now live in.

If I had that motor, I'd go ahead and make it look like the Beast it should be. I'd put a 750 (or bigger if needed) Dominator on it! But that's me.

Jay