Holley has new float bowls

[Tom Kirkham]

Holley has just changed their float bowls. Just noticed this when I was putting on one of our 9 in air filters. Of course we will have to modify things a little to make it work. Does anyone know the reasons for the change?





Here are some pics of the old style:

[Gunner]

Demon envy?

[mickmate]

The new gas was eating the insides out of a run of the earlier ones. They're making good on it as they had too much lead in the alloy I think it was. The new ones may be to differentiate from the old.

[Jerry Clayton]

Did you cut the choke tower or is that a new feature also???

[Tom Kirkham]

Originally Posted by Jerry Clayton

Did you cut the choke tower or is that a new feature also???

We cut it.

[Gaz64]

The needle and seat appears to sit higher on the new bowls.

[cdnus]

Two different model carbs also?

Craig

[Tom Kirkham]

Originally Posted by cdnus

Two different model carbs also?

Craig

Yes, the new one is a 830 DP, the old one is a 650 DP. But my older 830s have the old style float bowls.

[Tom Kirkham]

Originally Posted by Gaz64

The needle and seat appears to sit higher on the new bowls.

You are correct.

I will pull off the float bowls on Monday and see what is different on the inside.

[cdnus]

Just went to the Holley site & most all 4brl d/p seem to have the new float bowls.
I guess it is a across the board production change.

Craig

[Rick Parker]

Probably to aid in fuel flow entering the bowl.

[What'saCobra?]

Holleys

Rather than grind off the choke bell, consider using the Holley HP series, which has no bell and smooth/modern surface flow designs. With or W/O vacuume secondaries (double-pupers). Look at the pictures in the new catalogue.

Meanwhile, the HP also has high-Q or high-sensitivity low pressure fluidic sensors to properly meter fuel at low flow velocities, such as both WOT (wide open throttle) and low rpm (street use). The new HP series (http://www.holley.com/types/Street%20HPs.asp) is available in street versions. In a word, they are bolt-on great, the greatest.

i cannot tell you how many lost hours i wasted trying to get old 3310's to work correctly and never got them quite OK. Bolting on a street (or race) HP out of the box is simply shocking how good they meter at low RPM and WOT. Somebody over there got the picture about advanced fluid dynamics and coanda problems/advantages and put it to good effect.

See this for opinions that an HP is a .2 second bolt-on for the dragstrip.
http://www.chevelles.com/forums/arch.../t-158616.html

[PANAVIA]

Well that float bowl will mess up low profile air cleaner systems. -- fuzz.

[vector1]

i would guess different manufacturer. any guesses?

[zrayr]

I bought a 650 dp from Summit ( 4777-7) about a year ago, it is the "new" style" as shown above.

Z. Ray

[Gunner]

Originally Posted by PANAVIA

Well that float bowl will mess up low profile air cleaner systems.

Yeah, that sticks up a whole bunch, don't it?

I had to drill out a port on my long oval to get it to fit the Holley - old style, BTW - and then extend the hole to let the AC sit down over the Speed Demon's float screw. I sealed it with a rubber gasket from a fluid cap (generic part, the kind with a stiff outer ring and a soft bulls-eye center) epoxied to the lower AC plate. The float screw pushes up through the soft center and the outer ring acts as a bumper against the top of the bowl. Works great, even looks good.

[cdnus]

First time I've heard of "Them" descibed as a "fluid cap"

Craig

[PANAVIA]

We just got one of these in fro a customer project, they also seem to be jetted a little heavier than the previous generation.

Havent taken it apart yet, but on our air-fuel meter on the engine run-in stand on a stock 5.0L with a Stock 1989 roller cam and a basic dual plane street manifold ran a really rich F/A ratio .

probably is fine with more cam or more cubes, -- but worth passing along.

[zrayr]

Originally Posted by PANAVIA

We just got one of these in fro a customer project, they also seem to be jetted a little heavier than the previous generation.
..............." .

are you talking about the 650 dp (current ones are 4777-7) ? mine was rich as well, but had to jet up when I added the vintage Paxton to 72 & 84. Still don't have the idle right though.

am using one the these, it has helped a lot:
http://www.aempower.com/ViewCategory.aspx?CategoryID=67

Z. Ray

[Rick Parker]

By doing so they can sell more jets instead of answering causes of engines having been severly damaged by being run lean.