7045214, w/ complete kit from Cliff installed, recipe #2, WOT problem.

[spluhar]

@ 4000 rpm, the carb lays down.  It actually seems to be running out of breath before that, and by 4200 its all over.  It's a 71 429 Ford, 10-1 compression, ported heads, 216/224 @.050, 519/513 lift cam, and Performer intake, stock exhaust manifolds into 2.5 duals w/ x pipe.  Fuel pump is a Carter Muscle Car mechanical w/ 45 gph @ 5.5-6.5 psi., 3/8" rubber hose routed smoothly to the carb, 5/16" stock steel lines from the tank. I took off an Edelbrock 1407 750, which pulled strongly up over 5000 rpm, and I had a fuel pressure regulator on it set lower than it should have been (took that off).

[Cliff Ruggles]

Certainly fuel delivery related. Pretty small fuel lines for that power level, as a 5/16" line is only 1/4" diameter on the inside.

Rubber hose on the pressure side is NEVER a good idea, it soaks up heat and can cause all sorts of running issues, not to mention leaks and fires, etc.....Cliff

[77cruiser]

What size seat on the fuel inlet?

[spluhar]

Certainly fuel delivery related. Pretty small fuel lines for that power level, as a 5/16" line is only 1/4" diameter on the inside.

Rubber hose on the pressure side is NEVER a good idea, it soaks up heat and can cause all sorts of running issues, not to mention leaks and fires, etc.....Cliff

Small fuel line fed the edelbrock at this level w/ no problem.  I'll change out the rubber once this is figured out

[spluhar]

What size seat on the fuel inlet?

.135

[spluhar]

Pretty small fuel lines for that power level

It's slightly warmer than stock.  Mild cam, cleaned up exhaust ports, stock valves, regular performer manifold, no headers.

[spluhar]

Just double checked fuel hard lines: 3/8" (stock).

[429bbf]

older car?new fuel tank?my 72 ltd is set up real close to your setup. 9.7cr, perfomer intake ,isky 262 cam,17059212 carb . can't remember the spec id have to dig them out . car makes about 400 hp and 420 torque,pulled 5500 and then falls off . my cams only good for about 5500. my biggest problem was crud in the fuel tank . put on a new tank and problem gone . it kept plugging my fuel filter.all the lines are stock also the exhaust manifolds into the original y pipe connected to 3 in muffler and 3 1/2 tailpipe . i used a water pipe off a large haul truck that i had laying around.

[Cliff Ruggles]

Small fuel line fed the edelbrock at this level w/ no problem.  I'll change out the rubber once this is figured out

I'll bet you sucked to bowls pretty low in the E-carb as well.

The fuel delivery system needs to be adequate for the power level.

If you have installed a .135" fuel inlet seat and correct float setting, and are sucking the bowl dry, the fuel pump/lines/pick-up etc is pretty inadequate or restrictive.

I feed almost 600hp with a .135" fuel inlet seat at 7 psi with zero issues anyplace.  Even with that said, I fought fuel delivery issues for years until I went with a good system to keep the carb full on hard runs.  I even tried a Holley carb at one point, and the larger fuel bowls didn't help at all.  They engine still "laid down" just past 5000rpm's, I went about 10' further with the Holley carb in place and it started to do the same thing it did with the q-jet.

I upgraded the fuel delivery system, and the car picked up nearly half a second at the track and 4 more MPH with no other changes, and with both carburetors.......FWIW.....Cliff

[spluhar]

I upgraded the fuel delivery system

To what?  What do you recommend at this level?  I'm on a tight budget and the car is daily driven, btw.

[77cruiser]

That may not be enough pump, you might have to get something a bit bigger.
Maybe in the 100 gph range.

[spluhar]

45gph is 1 mpg @ 45 mph.  That's not enough?  5/16" id (.3125) (3/8" fuel line) is waaaaay bigger than .135 seat size. 

[77cruiser]

The pumps are rated at free flow, so under 5-6 lbs. pressure they don't put out that much flow.

[429bbf]

spluhar did you ever get your problem figured out? what kind of rig is this in ? just curious.

[spluhar]

No, haven't dealt w/ it.  I have a hard time spending another $130 on a $20 ebay carb.  A new fuel pump may not even eliminate the problem.

It's a 76 Ford Elite.  1971 429 w/ ported stock valve heads and a mild cam.  3:25 rear, cast iron manifolds, c6 trans.

What did Ford do w/ the 429cj?  What did Buick do w/ the GS455?  Mine isn't that far off of these notable qjet cars.