Holley VS. Edelbrock debacle

[UC645]

What engine is this on? Fuel dribbling at idle is NOT GOOD. Setting the float levels on the bench is the start, then they need to be adjusted on the car. Sight glasses make this a breeze. Otherwise, pull the plugs and set them high enough to just dribble out at idle. The transfer slots have to be set first, though. Those are the foundation of the idle circuit. Bring it down; we'll have it going nice in an hour.

A 350 Chevy. It has Vortec heads, an RPM Air Gap, and headers. The cam is from Howard’s, .480 lift on intake and exhaust, 282 degrees on intake and exhaust, and on a 108 LSA. I’ve got 1.6 ratio rockers on it so the lift is .512, I’m not sure if that has affected the duration. The fuel levels are just at the very bottom of the threads on the sight plugs, it spills out with a slight rock to the car. I’m fairly certain the secondary fuel bowl is either damaged, or was a defect piece. The fuel dribble only happens when I’ve got the choke fully closed, if I hold it open like in the photo, it stops. Might have to do with how airflow is directed into the venturis with the choke horn only open at the very front.

If I wasn’t replacing a well pump this weekend, I’d take you up on that offer. If the carb is still kicking my butt I’ll send you a PM on the matter.

I have an 800 cfm Quadrajet for sale that would solve all your problems. It was on my 442 and worked flawlessly. Throw that aftermarket stuff in the trash.

But I like my aftermarket trash....
In all seriousness I cannot keep buying stuff for this thing that I don’t need at the moment, but thank you for the offer.

A carburetor is a carburetor if they are set up properly they work properly. There are a lot of carbs that are built for various applications. As Fleming brought up the idle transfer slot is always messed with. Once you set the blades you don't touch those settings again and sure enough someone uses them for idle. Don't know your engine but I'm pretty sure you don't need 50cc pumps

I likely don’t need the 50cc pumps, so I’m going to step up the squirter size first. If that makes the stumble (and subsequent backfire) worse, I’ll reduce the size.


And here I thought this was going to be an easy project

 

[DRIVEN]

Aside from mentioning vacuum, you really haven't given us much else to work with. Engine displacement? Compression ratio? Cam specs? Converter stall? Power valve?


Edit: nevermind, looks like we were typing at the same time.

 

[500/600]

You absolutely positively do not need a 50cc pump on that carb

 

[fleming442]

...and an 850 is way overkill unless you're spinning it 9000 rpm.

 

[UC645]

Aside from mentioning vacuum, you really haven't given us much else to work with. Engine displacement? Compression ratio? Cam specs? Converter stall? Power valve?


Edit: nevermind, looks like we were typing at the same time.

I did forget a couple of things you’ve got listed.
The 350 has 10.2-1 compression, I think I’m using a 6.5 power valve, the trick kit came with two of the same valves, I’ll have to check, and I’ve got 3000 stall backed by 3.27 rear gears.

 

[gnvair]

I will add my .02 here....
The Holley has a lot more variables in tuning (pump shot via cams and discharge nozzles, idle jets, main jets, secondary pump shots or diaphragm springs, power valve sizing). It can get overwhelming for people that do not have the skill or knowledge or patience to properly tune all of the items. This is why people typically go for the Edelbrock/AFB.
As for the choke on a Holley carburetor; I have never had much luck with them (manual and electric) as they come. Holleys typically have a very strong pump shot and will always start regardless of temperature. The issue I have had is having to bump the idle speed up when cold. I found that the choke blade makes them too fat or too lean when cold. I typically remove the blade and just use the high idle cams. On my current 350 with a Brawler 650 I have an electric choke controlling the high idle speed when cold (again, no choke blade). I have a delay thermostat hooked up so that the high idle does not come on again when the engine is warmed up as the electric choke coils cool off quickly causing the high idle cam to engage again.

 

[UC645]

I will add my .02 here....
The Holley has a lot more variables in tuning (pump shot via cams and discharge nozzles, idle jets, main jets, secondary pump shots or diaphragm springs, power valve sizing). It can get overwhelming for people that do not have the skill or knowledge or patience to properly tune all of the items. This is why people typically go for the Edelbrock/AFB.
As for the choke on a Holley carburetor; I have never had much luck with them (manual and electric) as they come. Holleys typically have a very strong pump shot and will always start regardless of temperature. The issue I have had is having to bump the idle speed up when cold. I found that the choke blade makes them too fat or too lean when cold. I typically remove the blade and just use the high idle cams. On my current 350 with a Brawler 650 I have an electric choke controlling the high idle speed when cold (again, no choke blade). I have a delay thermostat hooked up so that the high idle does not come on again when the engine is warmed up as the electric choke coils cool off quickly causing the high idle cam to engage again.

Never thought of just removing the choke blade, I’ll try that tomorrow.

The myriad of adjustments on this thing are overwhelming at best. I’m thinking I’ve got too much of the transfer slots exposed at the proper idle setting (850 rpm) since I can’t stall the engine by bottoming out the idle screws. Or am I wildly off the mark with that?

 

[fleming442]

I'm down with ditching the choke, too. I've started mine in 30⁰ with no choke. Just have to hold your foot on it for longer. I'd imagine there's a convenience of a choke, and I guess it depends on use. Hot rod? Who cares? Daily? I got enough other stuff going on that I don't want to warm the car up. I've done it; you just have to factor the time in..

 

[565bbchevy]

Most of the old used Holley's have been modified and hacked by so many attempting to get rid of a stumble or bog and doing band aid fixes (50 cc pumps, big squirters etc.) and they are full of mismatched parts, the best bet is use your carb number to reference the original specs and build it to that for your baseline and tune from there doing one change at a time and keeping track of what you do.
The older versions have also had issues with porosity in the castings and no tuning can fix that but I will say the newer Holley's really work well I have a refurbished 670 Ultra Street Avenger with vacuum secondary and electric choke on my Regal's 355 SBC and a 1250 Gen 3 Ultra Dominator on my 565 big block and both carbs work perfectly with basic adjustments.
If they are available you can also get a refurbished Holley at a big discount over new.
I also prefer 3 circuits over the 2 circuit you have.

 

[MrSony]

I've had multiple qjets, a 600 Holley on my t bird and now an edelbrock on my f250. All work. Most of the time if not all the time the installer does it wrong or unknowingly puts a carb on that is in bad need of a rebuild. Not new gaskets. Not jets. A full on balls deep rebuild. Not to mention properly setting it up and tuning.