holley 4 barrel flooding

-
That float sure looked mechanically damaged.
Not original. That's from an older Holley.
Use the regualtor as a relief instead of on the feed if you can. Then by reducing the pressure get more flow to the bowl when oits called for.
Ideally shouldn't need to use a regulator with a mechanical pump. I know some of the Carters have spring rate that doesn't cut off flow until over 7 psi. :(
Holley's '110' mechanical pump was pretty good. Hopefully they haven't changed it.
 
Mattax said:
That float sure looked mechanically damaged.
Not original. That's from an older Holley.
Use the regualtor as a relief instead of on the feed if you can. Then by reducing the pressure get more flow to the bowl when oits called for.
Ideally shouldn't need to use a regulator with a mechanical pump. I know some of the Carters have spring rate that doesn't cut off flow until over 7 psi. :(
Holley's '110' mechanical pump was pretty good. Hopefully they haven't changed it.
Click to expand...

according to the procomp tech support, thats close to how the float should look
they cited holley 116-2 as a replacement

4271162_L_02e76445-e770-4e18-95aa-f11864063542.jpg

(i wonder if i can use a 116-3 instead?)

71UrQDz5H6L._AC_SL1500_.jpg

i have seen fuel systems with the regulator on the back and i know it works...i just cant wrap my mind around how it works

the pump is a carter M6270, which should run between 6.5 to 9 PSI
 
diymirage said:
according to the procomp tech support, thats close to how the float should look
they cited holley 116-2 as a replacement
Click to expand...


I'm surprised they are using a brass float, on what I assumed was an anodized aluminum carb. Not a big deal. But the damage at the top definately distorted its shape. I can't see the twist you in the pictures but I'm sure you are seeing it.
upload_2020-5-20_17-15-21.png

View attachment 1715531972
(i wonder if i can use a 116-3 instead?)
Click to expand...
Probably. It has the step up on the bottom to clear the accelerator pump.
View attachment 1715531973
i have seen fuel systems with the regulator on the back and i know it works...i just cant wrap my mind around how it works
Click to expand...
When the fuel pressure exceeds the set point, lets say 4.5 psi, it opens wider and wider relieving the pressure.
That's the simplest way I can explain it.
Maybe @Cudafever can do a better job since he has one and last fall he proved to himself that it can provide better control and more fuel at lower pressure.
the pump is a carter M6270, which should run between 6.5 to 9 PSI
Click to expand...
Argh! Same trap I fell into 25 years ago.
I had Ryan Brown test one of those. The one I had been using on my 340. The tested presure limit was 7.5psi What I found with .110 or might have even been .096 needle and seats was it was OK most of the time. Then it would bite me in the -ss. Eventually the pattern emerged - situation like cruising on the interstate and then letting off the throttle meant the rpms were up (say 3000 rpm) and the engine wasn't using fuel to speak of, and maybe the engine compartment was warm.

Carter M6902 has a softer spring in it, if you can still find an older one. Stated pressure limit was 6 psi on those.

My experience has been the Holley 12-360-11 has good pressure control. Or it did when I bought that model. I can't recall what pressure it showed on the gage - or if I even ran it with a gage hooked up.

Another trick is using a smaller needle and seat to reduce the force the float needs to resist.

lemme try to explain the pump flow and pressure.
The cut off pressure is what happens when the fuel going out hits a dead end. Zero flow.
What's happening inside the pump is the spring isnt strong enough to push the diaphram down.

Maximum flow (the one they brag about on the label) occurs when the fuel can flow out freely. No resistance at all.
So put those two together.
When fuel is can't flow out, pressure goes to maximum.
When fuel can flow freely, pressure out is zero.

Here's a graph Holley provided showing the flow at increasing rpms with the outlet pressure at 4.5 psi versus 0 psi.
upload_2020-5-20_18-2-53.png


Of course the dirt may be the main culprit in your case but thought you're interested in this too.
 
That brass mangled float look like it came out of the Dukes of Hazzard car after one of them famous jumps. LOL
Before i was talked into some test you could NOT have convinced me that lower fuel pressure was better.

Before my tests i was Going to Proven! that it will flow more fuel Quicker and faster the high pressure......................
I have been running as much pressure as i could get away with for all my life. AFB 7 psi, Holley'S 9 and nothing lower!!!!!

I did these test to Prove Several on my thread that they were full of B.S. And that my way Was the Right way in theory and reality.................................

I would have to go back to my thread to re read it to be exact, BUT here is the basic concept. we were comparing gal per minute compared to set pressure regulator setting.
with the pressure at 9 psi it took opening the float(I mocked this up with a ball valve) and dropping the pressure down to 7 pound before it was flowing enough to support 500 HP. (return flow regulator. At 9 psi it's all going back to the gas tank)
with the regulator sets a 6 psi(at 6 psi it all going back to the tank) it only to a half of a pound (5.5psi) to supply enough fuel to support 500 hp.

If the float can open sooner, and maintain a more consistent float level, the carb will perform more consistent.
 
Ok i when back and read this thread from the beginning.
adj the float while it's full it the proper way to do it on a holley. aka while it running.
The bouncing needle was not a bad gauge. the new gauge is a damping gauge so it don't show the pulse of the mechanical pump.

Holly Crap! that was a lot of dirt. us a magnet, i bet it is rust.........and probably came right out of the gas pump!!!!!
If a fuel truck is at my favorite gas station, i fuel up somewhere else. There stirring up all the crap up in there underground tanks and your pumping it into you car. Rant off:)
All that crap that ended up in you carb when threw you fuel pump and could be causing the one way check valve to not seal and leak. causing the gauge fluctuation.

When the fuel pump has filled the fuel bowls, to keep the pump from from raising the pressure it either by passes(another check valve, or the pump arm is held against its spring to keep the eccentric from pushing in the pump arm.

What i'm saying, is i don't thing that pump should be bouncing that extreme! Maybe if you had it going into a bucket it should/would bounce that much.

Maybe just driving it, will flush out the crap in the pump all by itself.
 
Mattax said:
Here's a graph Holley provided showing the flow at increasing rpms with the outlet pressure at 4.5 psi versus 0 psi.
upload_2020-5-20_18-2-53-png.png
Click to expand...

And while we don't know if the testing methods are similar, here is the plot of the M6270 Ryan tested for me.
upload_2020-5-21_7-45-28.png

Advertised free flow was 80 gph,
while the advertised free flow for the M6902 was 120 gph.
 
Mattax said:
That float sure looked mechanically damaged.
Not original. That's from an older Holley.
Use the regualtor as a relief instead of on the feed if you can. Then by reducing the pressure get more flow to the bowl when oits called for.
Ideally shouldn't need to use a regulator with a mechanical pump. I know some of the Carters have spring rate that doesn't cut off flow until over 7 psi. :(
Holley's '110' mechanical pump was pretty good. Hopefully they haven't changed it.
Click to expand...

after looking at it closer, it appears the damage came from the float being forced into the vent in the metering block

there was a TON of crap in there
i cleaned it all out, and hopefully were good

its odd on the gauge, it didnt bounce like that at first, so i wonder if the dampener got messed up?
either way, it wasn't a high quality gauge to begin with

i ordered a new float (did go with the brass, since i couldnt get a straight answer from holley on the 116-3)

should be up and running again soon
(maybe next winter i can replace the tank with a new/clean one)
 
All I can suggest for now is check the filters frequently, and if need be, use a finer filtration for the one in the line.

I'll see if the catalog from a few years back has any details on the floats.
Unfortunately, using Summit for buying small parts is expensive.

Holley tech-line has only gone from so-so to mediocre. :(
 
2012 Catalog says they are interchangable except for 4160s secondaries.
I don't even understand that exception. Whether it has a metering plate or a block, the bowl is the same.
Maybe its a more specific limitation than the editors wanted to get into.

Anyway, you've got a 4150 so doesn't matter.
 
I think the metering block bolts to a flat surface (more room)
were as the metering plate, bolts to the main body protruding into the fuel fowl a little.
 
You must log in or register to reply here.
-

Back
Top