Holley tech question for you.

Hello everybody, question for you all.

I have a cross ram Hemi and I'm running the stock, 660cfm, vacuum secondary carbs. Everything runs very well but fuel will start leaking out of one or both of the boosters on my passenger side carb.

Here are the things that I have done:
Change needle and seats.
Adjust float level all the way down to the point where it's just about closed.
Pulled that needle assembly out and exchanged it with one that does not leak....and it still leaks.

Info about the car:
Stock Carter fuel pump.
Idles at 950 in neutral and 850 in gear.
No electric fuel pump.

The cool thing is when you turn the the car off it will still leak even after you turn the car off!!

What am I missing!!

Thanks, Troy

is your tank vented and is the vent clear and working? I had a similar problem with my challenger. I used a vented cap but the hole for the vent wasn't drilled all the way so it wasn't working. If you drive your car then bring it home open the gas cap and hear a pssssssss then you found your problem. Just sitting in your driveway if it's still hot where you live should help you do the same test.

I had a similar problem with my set-up on my 500 max wedge clone.I noticed that the linkage was not equal and it keept the throttle blades just open enough to leak a bit ,adjusted and no more leeks.

One thing I would look at would be the float itself. It could have a hole in it causing it to keep the needle and seat open.
One other thing to look at is the bowl gasket, if might be keeping the float from rising up enough to close the needle and seat.
If none of those are the problem then you might double check the way you are setting the float level.

All very good possibilities.

I will check the the gas cap and make sure that it is vented.

The float is the solid, plastic type so there is no hole. I checked the gasket and the float is free of all obstacles.

Float level is all good....I just checked it again. I even have it a bit on the low side.

float waterlogged, mechanically hanging up in it's range of travel, damaged O ring,need to lube it 1st before installing, fuel psi borderline too high. I'd swap the pri bowls & see if the flooding follows the bowl since you swapped a known good needle/seat & if the O ring is undamaged there might be a prob with the bowl itself.

Maybe the fuel is being pushed due to percolation...
When the engine is shut off and the engine temperature rises it causes the fuel to boil in the bowl and leak out of the boosters. A couple of possible fixes..
1. Adjust the float level down slightly..
But U said this has already been done..
2. Add a thin phenolic spacer under each carb..
This will insulate the carb to keep its temperature lower, and minimize the boiling of the fuel. As today's unleaded fuels seem to have a lower boiling point..

Note that I had a similar problem on my B5 RoadRunner, put a short phenolic spacer (0.125") under the 770 Holley and problem solved...

Just my $0.02...

Moparsquid is thinking along the same lines as I am here. Make sure that the throttle plates on that carb are not open a little too much so that they are pulling on the mains.

hi
what is the list no of your carbs ?

perhaps a leaking power valve ?

what vacuum is the engine pulling warm in gear ?

what no power valve do you have in them ?

a wrong or toren power valve gasket ?

perhaps a bad metering block gasket ?

a float that has become fuel soaked , have you weighed it ?