Fuel or Fire

I need some help,

My car will run for the first 80 feet for the track and then just falls on its face.

I have talked with Don at Hilborn, Kent at Enderle, Don Hampton and Joe P. at MSD.

I have a 12 amp mag and a nitro barrel valve I have checked all of the lines the poppets the tank everything I know to check and everything I have been told to check.

It will run hard and then it will only take about 1/8 of the throttle and kind of blubber the rest of the way down the track. It blows fuel out on the windshield.

I have replaced the MSD box not the Mag, put a #16 line to the pump disconnected the kill switch and kill it by the fuel shut off only. Still no help.
It has made 9 pass 1.05 to 1.08 60 footers leaving at idle 1800 rpm, then does as I described. It is a power glide converter car. 2470 lbs

Any Ideas I am Lost.

 

Not enough info; call me 619-440-7701
If it's blown, crazy as it sounds, the rotors might be in backwards, they idle real nice though.

 

I agree the blower rotors may be backwards, they will spray fuel out the back nozels the blower. When was the last time you restriped the blower and did it run ok before that???

 

Thaks Guy's

I checked the blower and that is not it.

I have put a new pump on it and a added a second vent to the tanks. Not that I think something was wrong with either one of just because.

Bob, it was nice of you to take your time and visit with me on this matter.

Still Looking for the problem

 

I doubt that the fuel tank vent is the problem, if the vent was a problem the engine would go lean. Is the mag new or used, if used have you had it checked if new could also be bad. As confucious would say (Just because it's new doesn't mean it's right). Are the plug wires new or used if used and they came from a MSD 44 pitch em. Used plug wires will leak and short out causing all kind of problems. Are the wires in seperators or tie wrapped together? Wires shouldn't be tie wrapped together. Do you have the mag grounded to the chassis and the engine?
Bad grounds cause problems. Have you rechecked TDC, cam & ignition timing? Double check TDC with a postive piston stop & recheck timing.
Has the fuel system been flowed? What size pump?To big of a pump will idle Ok because of the idle check valve is bypassing fuel to tank or inlet side of the pump and only X amount of fuel can pass through the notch on the spool in the barrel valve.
Don't mean to ask stupid or fuelish questions but it is the stupid and fuelish things that give us the most trouble.
Race cars tell us exactly what they want, we just have to be smart enough to figure it out.
Good Luck
Bob

 

Is the mag the correct one for the rotation???---I heard of some guys having a similar problem and found they had been sold the wrong mag---would run, but timing would jump around like crazy limiting performance

 

New 12 amp mag new wires new plugs .018 gap all wire are ran in the MSD wire guides. I have the points box grounded to the heads the heads grounded to the block the block grounded to the chassis. Checked the phase of the mag and timing 32 Deg BBC.
I have a 110 pump 1/2 of crank speed. I have checked to make sure. I have a CW rotation mag and it is fine. I am running a 160 main jet. No down port's 10, 52 in the hat and 2, 40 for the blower. I ran this set up last year and it would run 6.70 205 all day no problems.

I fell it is going fat, however can it go lean really fast and cause this problem? It never pops or bangs.

Thanks for the help guys.

Still looking for the problem.

 

I'm still thinking on this after we talked, I love a puzzle. I guess I was thinking too much at the time and didn't let it sink in you had a 160 main.
On a good day (if I remember correctly) a 110 pump flows 10.7 GPM, with no other jets even, this deal would have very little fuel pressure, and be producing about 7 GPM @ 8000. You now have a real ignition and a fresh blower, making me beleive it's way too lean. If it were me, I'd put a 60 in it and hang on. My guess is, if you put a 120 in it, you'll probably burn all 8! Right now it's running on smelly air, not enough fuel to even hurt anything.
Have you called Tom yet? Seventy miles isn't far to drive to solve this mystery.

 

We have also been leaning to the lean side, and we put a 120 in it to try. I am going to test Friday AM before the Clash of the Titians race in Oklahoma.
I did call Tom's shop he is out. He is doing inventory in Tulsa on Shelly H. rig and parts. A task that I am sure he is not enjoying.

Todd

Still looking for the Problem.

 

Todd; I'm not a racer anymore, just a welder, but I certainly would not dare to put a 120 in it until I made 10 runs with a 60 to 70 in it, and read the bearings and oil contamination.
It's called "been there- done that", "no wonder I can't afford to race anymore", "I know what dumb is".......... Good Luck from the Old Guy

 

ill throw my ignorance into the deal,but ive been lost before and a lot of bad info is better than none at all. i had a similar problem which turned out to be the spindle in the barrel valve was 180 degrees out . it will leak down at idle just like normal,but wont work at wot . the enderle shafts have a notch in them to designate orientation,but the old ones dont! your only lost if no one helps!

 

We think we have found the problem. To much air in the fuel in the return line in to the tank.

We made a few changes to the return line into the the tank and it has solved the problem so far, However I had an attack of Kidney Stones.
I have never had before and then blew low gear out of the trans before getting a full pass under power.

Thanks

For the help and I will let you know if this was truly the problem as soon as I get the trans and myself fixed.

Todd Martin

 

Consider getting rid of the return line to the tank. Return lines back to the tank can airate the fuel in the tank. Plumb it in to the bottomn of the pump. Plus you get an advantage. You save a little weight.
Bob

 

if i were you i would not try the 120 main,as bob meyer said,and i totally agree,that probibally will put you lean enough to take 8 pistons before you can back off the pedal.try a 070 main,if it,s to fat ,you,l know,but much safer [and cheeper]to error on the rich side.a lot easier to change oil than pistons.if it runs better with the 070 main,sneek up on it 010.at a time.150+ main and 110 pump= not a lot of fuel,maybe enough for a lawn mower,not much more.goodluck&keep us posted.