Running out of fuel on the big end..

[64PI]

Looking for others input on what they are running for a fuel system on their drag cars. I'm currently running a Holley blue, 8AN line with a in line filter, Holley regulator set @ 7psi to a pro systems 1000cfm carb on a victor. The engine is a 451" stroked 390 with CNC edelbrocks from BarryR, .700" lift solid cam with duration around 265-270@.050. I cannot get any color on my plugs going through the traps no matter how much jet I throw at it. I've check and found no vacuum leaks. The car goes 11.14 @ 118mph. The car is a '64 galaxie weighing about 3650 with me in it. C4 trans with a 5500 stall converter. 4.20 gears and 29" tall hoosiers. It goes 1.50 in the 60' and high 6's in the 1/8. It seems like I'm loosing something on the top end and I believe it to be fuel related. I have good color on the Autolite race plugs cruising to the track @ 3500-4000 rpm. I'm going to be tearing the fuel system apart and sending the carb back to pro systems for a check up. Any thoughts are appreciated. I'd like to get things figured out and make it to the Reunion and try and get a 10.90 out of the car.  Thanks..Fred

[6667fan]

Is it actually nosing over or are the plug colors the only concern? Some sort of A/F reader and accompanying logging device might be the ticket if you want to get some usable/helpful data.
Great lift shot there. Love the lines of a 64 hardtop. JB

[64PI]

I'd say its a combo of plug color and top end performance.  I will dig out my time slips when I get home so I actually have numbers to compare 1/8 vs. 1/4 mph and times. I should look into some sort of A/F reader and a way to log the info.. I've tried going up in fuel pressure, raising float levels to going up 8 jet sizes with no change to the plugs or et/mph. Fred.

[shady]

Did the car ever run in the 10s? Myself, I think you have it wrung out pretty good.

[64PI]

The car has never seen a 10... I'm hopeful with my fuel situation situated I can squeak it in. I believe there is more left in it... especially with running 11.14@ 118 while going lean on the big end. Or maybe I'm just dreaming....

[Joe-JDC]

Sounds to me that you are running into frontal area vs gear ratio at speed.  You either need more horsepower, or more gear to push the car through the air.  I ran 4.57 gears in my Mach I with FE for 10.90s, and 5.13s with sbf.   That Pro Systems carb should have been close out of the box.  If you still have 7 psi going through the traps, you do not have a fuel delivery problem.  Joe-JDC

[shady]

Beaver is notoriously slower than other tracks because it is slightly up hill. Used to be .2 slower than Maple Grove or .1 than Numedia.
Don't know if that still holds true. I think you have a great running car and those tenths are hard to find and expensive, but keep on looking. Be great if you could find another 2 or 300 pounds to lose.

[64PI]

Sounds to me that you are running into frontal area vs gear ratio at speed.  You either need more horsepower, or more gear to push the car through the air.  I ran 4.57 gears in my Mach I with FE for 10.90s, and 5.13s with sbf.   That Pro Systems carb should have been close out of the box.  If you still have 7 psi going through the traps, you do not have a fuel delivery problem.  Joe-JDC

That is a good point, Joe. I am possibly trying to tune in time that isn't even there. I have had my hands on the pro systems for a few years now so I could have sent that right out to lunch. I also need to cowl mount my fuel pressure gauge so I can check it at speed. I am setting the pressure off the gauge under the hood and at idle.

As far as slow tracks that's all I have been running on. I run at ESTA dragstrip in Cicero, NY. Its up hill and against the wind.

[machoneman]

Run it, get outta the car immediatley after the run and pop the fuel tank cap. If you hear a 'whoosh', bad or non-existant tank venting. That or blue-tape the cap with some strategically palced holes so it's NOT tight,make your run and see what happens.

Ask me how I know this.............

[My427stang]

The odd thing is color on the plugs driving there, but clean at WOT even with more jet

Is this anything funny like an aerosol carb, or do you have jet extensions that could be holding the float back and not opening the needle/seat all the way?

ET is what it is, but odd if plug color and/or trap speed isn't changing with jets

When able, post the carb design, LIST # if appropriate, booster design, front/rear PVs and max jet sizes you have tried

[BigBlueIron]

I also need to cowl mount my fuel pressure gauge so I can check it at speed. I am setting the pressure off the gauge under the hood and at idle.

I have in a few cases rigged up something to hold my phone taking a video to witness something that is otherwise not accessible. Gorilla tape and zip ties can do amazing things.

[64PI]

The carb is a Pro form 4150 1000hp series carb with Venom2 metering blocks. Jet extenders in the rear and stepped high signal .156 boosters. I have ran the car at the track with this combo 2 different times and I will share the info for each so this might get lengthy.

#1. With M/T Drag radials. 1.54. 60’. 7.08 1/8@96mph and 11.18@118mph.
Started with 84/92 jets and worked all the way to 90/98 with no color change or change in Mph. Tried adjusting fuel pressure and float heights and no change. Also a 6.5 PV in front.

#2 Hoosier slicks. 1.50 60’. 7.03 1/8 @ 96.8 mph and 11.14@118.67mph. All improvements in time due to the slicks. Now here’s where it gets funny. This time I blocked the PV off. Squared the jets up at 94 amd still clean plugs on the top end. Don’t ask why i did this I had a hair brained idea.

I can accept the fact it’s not going to gain any ET. But not being able to get color on the plugs is concerning to me. I have the fuel cell vented with also.

[WerbyFord]

The carb is a Pro form 4150 1000hp series carb with Venom2 metering blocks. Jet extenders in the rear and stepped high signal .156 boosters. I have ran the car at the track with this combo 2 different times and I will share the info for each so this might get lengthy.

#1. With M/T Drag radials. 1.54. 60’. 7.08 1/8@96mph and 11.18@118mph.
Started with 84/92 jets and worked all the way to 90/98 with no color change or change in Mph. Tried adjusting fuel pressure and float heights and no change. Also a 6.5 PV in front.

#2 Hoosier slicks. 1.50 60’. 7.03 1/8 @ 96.8 mph and 11.14@118.67mph. All improvements in time due to the slicks. Now here’s where it gets funny. This time I blocked the PV off. Squared the jets up at 94 amd still clean plugs on the top end. Don’t ask why i did this I had a hair brained idea.

I can accept the fact it’s not going to gain any ET. But not being able to get color on the plugs is concerning to me. I have the fuel cell vented with also.

Well since its a 64 Gal I will try to Gonkulate it anyway. Guessing 2-1/8 open headers? Cold air to the carb or underhood? Is it turning the water pump (& fan?) All that stuff would affect trap speed.

What about wind, what is a typical headwind for those timeslips? I always check cuz a 5mph headwind will cost you about 1mph trap speed. Depends on the aero of the car, etc.

But first guess - rule of thumb I use is, your 1/8 MPH should be 80% of your 1/4 MPH. Yours is right in there, within 1mph or so anyway.

What about a fuel pressure gage then video it running down the track?

[Joe-JDC]

What fuel are you using?  May not read like you expect.  Joe-JDC

[64PI]

I’m running Sunoco 93 octane. 10% ethanol. It leaves “normal” color on the plugs cruising  3500-4000. I’m running 2 1/8” cross over headers into 3.5” straight through dynomax mufflers. Exhaust ends before the axle. No air filter at the track. Running a water pump, fan and alternator off the engine. Compression is 11:1. Cam specs are .700” lift int/ex. 266/274@ .050 108lsa installed at 104ICL. Cnc edelbrocks from Barry and a port matched victor. I would guess average wind speed to be 2-5mph. Aerodynamics of the Bismarck. I am definitely mounting a fuel pressure gauge on the cowl before the next track visit. Fred