Bad night at the track " UPDATE"
#438336
08/14/09 11:08 PM
08/14/09 11:08 PM
|
Joined: Aug 2006
Posts: 1,613 Deerfield, Ohio
70dusterjohn
OP
top fuel
|
OP
top fuel
Joined: Aug 2006
Posts: 1,613
Deerfield, Ohio
|
Well just got back from the track, and let me tell ya I should have staied home.First off I had to stop three times on the way out there, cause my trailer lights went out.. So I can deal with that, I got them fixed and on our way. Get to the track and un-load the car and take it to warm up. Right of the car just didn't sound right.. it starts to stall, now what.. Well dumby me forgot to take the cab hat off.. Well that wouldn't be the last time for that.. I ended up doing it three times total. Okay so I take the car up and do the burn out, all is right with the world, stage the car and bam I slap the gas, the car just blows the tired off.. then went hard to the left, what the heck is that.. so I'm out of the gas right after second gear.Come back check the tire pressure, its at 20lbs not good.. So I drop the pressure, take the car back up.. Stage it leave, okay that felt better, pull second its still pulling hard, pull third and thats when it all starts, the car starts bucking, falling on its face and then picking up again.. I look at the fuel pressure and its at 2.5 and bouncing to 3.0 and back, so I get out of the gas at the 1000ft marker and runs 10.17 at 132.963 So I think the prerssure is to low.. Soooooo I raise it up to 7, I had it set at 6 the runs before.. Go back up and the same thing happens.. third gear falls om its face, 2.5, 3 pounds, so I back out of it again at little past the 1000 ft runs 10.02 134.623 What the crap is going on.. Come back jack the pressure up to 7.5 pounds, go back up for the same thing.. Third gear 2.5, 3 pounds, runs 10.02 130.236.. Man I'm done, so I load it up and come home. Sooo whats the deal??? I got no idea, the only thing I did was replace the holley blue pump with the new Mallory 140 plus regulator.. I don't understand what the problem is.. I'm bout ready to pull the pump off and throw it as far as I can, and put my crappy blue pump back on. Go with a better pump and go slower, went 9.80 with the crappy blue pump.. Any ideas.. Let them fly..
Last edited by 70dusterjohn; 08/15/09 12:51 PM.
|
|
|
Re: Bad night at the track
[Re: 70dusterjohn]
#438342
08/14/09 11:19 PM
08/14/09 11:19 PM
|
Joined: Aug 2003
Posts: 43,129 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,129
Bend,OR USA
|
What is between the pump and the tank? A freind of mine recently upgraded his fuel system and had a similsr problem, the new pump would suck the fuel filters dry which ended up driving the fuel pressure down at the carbs. His old system was two Holley blues(one started leaking) with two Fram chrome canister fuel filters between the fuel cell and the pumps, out of the pumps into a Y (all # 8 lines between the Y and the fuel cell) and then a # 8 to the front with two little Holley fuel regulators, one for each carb. He replaced the pump with a BG 480 and athe little Holley regulators with a four port Aeromotive return style regulator with a #10 feed from the back and a # 10 return to the cell The only thing he left was the two Fram fuel filters fed by 2 # 8 lines into the Y and then into the BG 480 He now has two inline 40 Micron Aeromotive fuel fliters that are rated to flow a lot more than the two Frams that where rated at 90 GPH or less
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Bad night at the track
[Re: 70dusterjohn]
#438348
08/15/09 12:28 AM
08/15/09 12:28 AM
|
Joined: Aug 2003
Posts: 43,129 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,129
Bend,OR USA
|
Quote:
What do ya mean MR P Body.. How do I check that??
You disconnect the fuel lines to the carb and place them into a safe container, two or more gallons, bigger is better on this one. Turn the fuel pump on fornine, ten or eleven seconds and measure the amount of gas in the container in ounces, do the test several times (sameamount of time on each test )so you get a average. Barry Grant has a chart for fuel consumption measured in how many seconds it takes to pump one gallon, hopefully some one who knows how will post a link to it what I remember is a nine second car needs to pump one gallon in twenty seconds or less, a ten second car needs to do it in 25 seconds, I think anyways. I might have the numbers skewed some IHTHs
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Bad night at the track
[Re: Cab_Burge]
#438349
08/15/09 12:31 AM
08/15/09 12:31 AM
|
Joined: Aug 2006
Posts: 1,613 Deerfield, Ohio
70dusterjohn
OP
top fuel
|
OP
top fuel
Joined: Aug 2006
Posts: 1,613
Deerfield, Ohio
|
Quote:
Quote:
What do ya mean MR P Body.. How do I check that??
You disconnect the fuel lines to the carb and place them into a safe container, two or more gallons, bigger is better on this one. Turn the fuel pump on fornine, ten or eleven seconds and measure the amount of gas in the container in ounces, do the test several times (sameamount of time on each test )so you get a average. Barry Grant has a chart for fuel consumption measured in how many seconds it takes to pump one gallon, hopefully some one who knows how will post a link to it what I remember is a nine second car needs to pump one gallon in twenty seconds or less, a ten second car needs to do it in 25 seconds, I think anyways. I might have the numbers skewed some IHTHs
Thanks Guys, I'm just pulling my hair out with this one. It was such a wasted night.
|
|
|
Re: Bad night at the track
[Re: Cheatham]
#438352
08/15/09 02:41 AM
08/15/09 02:41 AM
|
Joined: Aug 2003
Posts: 3,245 Between a rock & a hard place
cudadoug
master
|
master
Joined: Aug 2003
Posts: 3,245
Between a rock & a hard place
|
First of all, it wasn't THAT bad; you didn't wad it up or blow it up!
I had the EXACT same problem once. Reset psi, changed regulators twice, changed pump relay, pump switch, re-wired pump/relay wiring, changed carbs twice, changed pumps THREE times...same problem. Changed brands of fuel THREE times, no solution. Pump test? Each time and each pump passed with flying colors? I'm pullin' what's left of my hair out...GRRRRRRRRRRRR. Wife says, you've changed everything but the fuel cell, might as well try that. I do it, all the while thinking she's nuts, but what the heck...
New cell: Problem solved. Turns out the foam was breaking apart and upon acceleration a chunk was covering the sump!! Who woulda thunk THAT??!!??
Cover ALL of the basics first, don't ASSume all components are working correctly...check everything!!
Good luck and let us know what happened.
|
|
|
Re: Bad night at the track
[Re: 70dusterjohn]
#438354
08/15/09 11:24 AM
08/15/09 11:24 AM
|
Joined: Jan 2003
Posts: 3,616 Riverside, Ca
G_bob
master
|
master
Joined: Jan 2003
Posts: 3,616
Riverside, Ca
|
FWIW, I was running the mallory 140 in the coronet with the old motor making 550 hp or so. With the new motor doing 770 on the dyno, Brian was concerned that the 140 wouldn't be enough pump.
I called RobbMC (before opening his business he was a design engineer at mallory) and he confirmed the 140 would be marginal at best at my new power level. Mallory lists it as for 600 hp max (600-700 with a return style regulator), and he said they do build a safety factor into their published numbers.
They list the 250 as the recommended pump for 700-1200 hp applications. So, the car now has a mallory 250 in it.
Based on your et's, you're makng around the same or better hp than I am, so I'm going to say the 140 just isn't enough pump.
|
|
|
|
|