carb. crazzzzyness!!!!!!!!!

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rumblefish360 said:
6 packs are rated at a 2bbl. Each for that total. If rated as a 4bbl. they would equal 780CFM.
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Not only that, the original AFB / AVS were not rated the same as Holley 4bbls. If I remember right, the Carters were rated "wet" flow, the Holleys "dry" so the Carters actually flowed more as compared to Holley

So far as Holley 2bbl/ 4bbl, very good point. The 4bbls are rated at 1.5" (water) vacuum and the 2bbls rated at 3". A 500cfm Holley 2bbl for example, works out to about 350 CFM when rated as a 4 bbl
 
67Dart273 said:
An aside, I didn't realize the 750 Edelbrocks had such a bad rep. What in your opinion is their major problem?
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They tend to have an incurable off-idle stumble for one, unless you drill the emulsion tubes, and that's not a guarantee either. Even with the biggest jets and smallest rods, biggest pump shot, etc., it can still have lean spots. This is my current carb. Kind of a theft deterrent though:banghead:
 
IDK how the carbs are rated for sure. Last time I see. Something about carbs on TV, I think it was Hot Rod TV, Holley wet flowed there carbs. I'm not a 100% on this.
 
65TerrorCuda said:
They tend to have an incurable off-idle stumble for one, unless you drill the emulsion tubes, and that's not a guarantee either. Even with the biggest jets and smallest rods, biggest pump shot, etc., it can still have lean spots. This is my current carb. Kind of a theft deterrent though:banghead:
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I have heard this, but I've also heard that Barry Grant carbs had lots of problems , until Holley bought 'em out and fixed them.

You'd think if the Eddy 1407/1411 problems were that bad and widespread, they'd fix 'em.
 
Don't misunderstand my position, I have nothing against the Edelbrock carb, I'm just at a loss as are the shops which have looked at the Dart to figure out what and where the problems are which are causing it to run so poorly. For all I know, it isn't the carb and may lie elsewhere. @ this point it's just frustration which I'm choosing to vent here.
 
Hey thanks all for the different suggestions and I have chosen to work with this holley until its figured out. Atleast a little longer lol. As I said before that im not a super mechanic but i have assembled a dozen or so classic/muscle cars on my own. Its a bit offending to ask a question when i get stumped (as we all do unless your god) and get a response of "buy a book and read it". Just for information purposes i did buy a book, 3 of them on holleys as a matter of fact and I also had a tech guy from Indy Cylinder Heads physically look at the car with no results so its not because of my lack of effort or lazyness that i have an issue with my car. Im sure its just a small tweak that will be finalized and all will be fine. Thanks again for all the positive support and i did learn some good ideas on here from the guys who wanted to help out a fellow member!!!!!!!!!!!
 
340_dart_power said:
Don't misunderstand my position, I have nothing against the Edelbrock carb, I'm just at a loss as are the shops which have looked at the Dart to figure out what and where the problems are which are causing it to run so poorly. For all I know, it isn't the carb and may lie elsewhere. @ this point it's just frustration which I'm choosing to vent here.[/

And I say this with respect. Time to stop depending so much on shops,and figure out what makes this thing tick,on your own. I would start with ignition,and work from there. What's your timming set at? Are you running vacuum advance?What ignition are you running? Bad ECU/coil? Ect,Ect.Then learn what makes the Ede 750 tick. It could just be out of adjustment.Take it off and put it on the bench. Take the top off.Adjust the floats. Blow out all the ports. It could be as simple as a piece of dirt in a jet. This can happen with any carb. Again,I mean no disrespect. But to be at a loss of the problem,and blame it on the Ede 750,doesn't make sense.
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Johnny Dart said:
Venting at the expense of Edelbrock.
And I say this with respect. Time to stop depending so much on shops,and figure out what makes this thing tick,on your own. I would start with ignition,and work from there. What's your timming set at? Are you running vacuum advance?What ignition are you running? Bad ECU/coil? Then learn what makes the Ede tick. It could just be out of adjustment.Take it off and put it on the bench. Take the top off.Adjust the floats. Blow out all the ports. It could be as simple as a piece of dirt in a jet. This can happen with any carb. Again,I mean no disrespect,but untill you learn what makes this thing tick,blaming the 750 is just wrong.
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Understood, and no offense taken. Hopefully Edelbrock's shoulders are broad enough to handle my venting (lol).
 
Just curious here, why are there so many people running 750 Edelbrock carbs when the 800s are known to be good and only 50 cfm more than the 750? I feel like any engine that can handle 750 cfm could handle 800 without issue and it would obviously run a lot better since the 750 is notorious for running poorly.

BTW @ 340_dart_power Edelbrock/Carter carbs are super easy to work on and the only reason a professional tuning shop would refuse to work on one is because A) they're stupid or B) they want to sell you a Holley...
 
440nika

Get your timing figured out FIRST!

Think of it analogous to build a house. Timing is the foundation. If you don't have a solid foundation, how is the rest of the house going to be from a soundness standpoint. Care to build a roof before the foundation, wall are up?

I suggest you get comfy using a timing light and learning how the curve works. Hook it up, point and shoot, read results... it's not that hard. There are a few methods to determine how much initial timing to run, Kick back, vacuum gauge. This topic comes up often and there are MANY threads regarding it.

Use the search function "hillbilly timing tape", you'll never need dial back timing light or timing tape. Just the ability to add and subtract
 
I can't say I have had a problem with the 750's in the past.
 
OK did a little surfing, this is off a Buick forum:

The difference is in the venturies. On the 750cfm, the large venturi is 1 3/32in. On the 800cfm, the large venturi is 1 7/32in.

In laymans terms, they use different castings for the airhorn.

Apparently the metering rods and jets are different too along with a higher-capacity accel. pump... maybe these parts are marginally too small on the 750??
 
440nika said:
Hey thanks all for the different suggestions and I have chosen to work with this holley until its figured out. Atleast a little longer lol. As I said before that im not a super mechanic but i have assembled a dozen or so classic/muscle cars on my own. Its a bit offending to ask a question when i get stumped (as we all do unless your god) and get a response of "buy a book and read it". Just for information purposes i did buy a book, 3 of them on holleys as a matter of fact and I also had a tech guy from Indy Cylinder Heads physically look at the car with no results so its not because of my lack of effort or lazyness that i have an issue with my car. Im sure its just a small tweak that will be finalized and all will be fine. Thanks again for all the positive support and i did learn some good ideas on here from the guys who wanted to help out a fellow member!!!!!!!!!!!
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Cut your losses/headaches. Either sell,or put the double pumper on the shelf,for a 4spd build.Get yourself a vacuum secondary carb. You'll be way ahead of the game,with it.

And reading is good.Knowledge is King !!!!
 
BillGrissom said:
A spreadbore (ThermoQuad or Quadrajet) is best for driveability and mileage, but good used ones are rare. I vaguely recall reading of new Quadrajets. TBI would be even better, but more complicated. With either carb or TBI, you need an O2 sensor or you are "flying blind". Best is a wideband kit and prices have greatly dropped.
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x2 at the risk of getting flamed i was going to say find a olds or old caddy and get the quadrajet off it they work good and get decent milage. shut up everyone !
 
65TerrorCuda said:
I've got a Holley Projection 2D with a remote dial box so you can suffer from the comfort of your driver's seat. Like new!
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I have run one since 1996 in my 65 Newport 383, but hard to recommend it. Seemed to run better with the older "analog" box, usually staying in range for O2 feedback. With the later "2Di" box, I constantly have to tweak the knobs to keep it in range, but maybe a "bad box" problem (erratic pot.s). I have ideas to improve the Pro-jection, but a Commader 950 in all my cars is my immediate solution. I am fascinated by carbs, but seems always a mystery how well they are working inside.
 
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