1050 Holley dP dripping from one booster

[cuslog]

Friend of mine has a 1050 Holley DP, its got a steady drip from one booster.
Alcohol carb.
Fuel pressure is about 6.5, new needle and seats (.150 IIRC), floats set to bottom of sight window.
Soaked it in carb cleaner, blew it out good.
What would make it drip like this, from one booster only (secondary side) ?

[raceman14]

Idle circuit could be messed up along with the idle air bleed. It is usually best to blow them out from the metering block side as to not jam the clog down the idle tract any more.

If that is not the case I would check all of the booster holes as that one might have something in it making the size reduce and pull more fuel from the same booster signal as the other 3.

You can also try lowering the float level 1 flat at a time and see if that solves the problem. The bottom of the sight hole is not always the right level for the float, although it has been the rule of thumb for 50 years.

Needle and seat would not be the problem as does not meter fuel to booster it is kinda like the bowl valve in the toilet, it just fills when the float drops and raises the needle off the seat. Now you can get into a quandry there if the fuel pressure is blowing the needle off the seat when it fills and causes overfill but that would not be at idle so I guess you are OK there. Kinda thinking out loud as I type...

That is what I would check first if it was mine.

Could be a rare case of more booster draw out of that booster which can be checked on a flow bench pretty easliy. I have corrected that before by relocating the booster properly or reaming it out a couple thousandths to equalize the signal to the other 3. I'll be watching to see what you find.

[levisnteeshirt]

i'd check to see if the throttle shaft is bent causing one barrel to be more open at idle

[cuslog]

Just to follow up on this;
Buddy dropped the floats 2 flats below the bottom of the sight hole and no more drips from the booster.
Thanks for the replies,,,,,,,,,, I wouldn't have thought ,,,,,,, I've run mine quite a bit higher with no problems.

[Alan Roehrich]

Just to follow up on this;
Buddy dropped the floats 2 flats below the bottom of the sight hole and no more drips from the booster.
Thanks for the replies,,,,,,,,,, I wouldn't have thought ,,,,,,, I've run mine quite a bit higher with no problems.

That's a band aid fix, there is definitely a real problem with the carburetor, and he's probably screwing up the metering on the other side in order to "fix" the dripping side. Certainly not the way to go about it.

[MadBill]

Could also check the blade clearances F Vs. R. If the rears are significantly further open, it might be borderline for rear boosters dribbling at idle and one is just a little ahead of the other...

Also, for some apps such dribbles are normal. When we first fired our new Braswell-equipped SB2.2 Trans Am car several years back, the left front dribbled a bit. We called Braswell and the conversation went like this:

Us: "We've got one booster dribbling at idle..."

Braswell: "Is it an SB2.2?"

Us: "Yup."

Braswell: "Left front?"

Us: "Uhh, yup."

Braswell: "They all do that."

Us: "OK, thanks."

It made 701 WHP and has run like a trooper ever since...

[cuslog]

Could it be that as someone else mentioned " the sight plug hole isn't always in the right place for a particular app. ?
I mean dropping the floats 2 flats isn't such a big change is it ?
He did change the float on that side and had to start again from scratch.

[Doug Schriefer]

Fuel dripping out of a booster at idle can be a number of things:
- Butterflies open too far causing the main circuit to start
- Dirt in the air bleeds causing the circuit to start sooner than wanted
- Air pulses in the engine
- Float Level too high
- Fuel pressure too high

So first check to make sure the air bleeds are clean, and the butterflies are open an equal amount on all four. Check with whomever built the carburetor, but typically most guys running Methanol do not run that much pressure at idle. I do not like setting floats by a site plug or site window as it will change based on fuel pressure, angle of the car, atmospheric conditions, etc. Setting the floats using a pair of calipers is the best way to go about it.