Engine "run on" after i lift at the end of the run.

526 aires. K11 Superman, K style barrel valve, endrele 1200 pump. Idle check set at 12psi, pump saver at 160 psi port check at 13 psi. barrell valve leak at 80%.
When I lift after the run, the motor won't come back down to idle. It didn't do this until I changed blower, barrel valve and pump. My old stuff was set up the same way and never had a problem. These parts came off a drag boat and I was wondering if there is something different about the barrell valve. It's hard to stop when the motor stays at 4500rpms after you lift. I think it is a lean condition.
Thanks for your help
Kenny

 

Ice holding butterflies open?
Idle speed screws on butterflies rotating in during run? (Guess how I know about this)
Fuel pulling away from inlet in tank during deceleration?

I am having the same symptom. We have alot of rocks in our shutdown area, so I have to leave my engine running until the car comes to a complete stop to keep from loading the pipes (and cylinders) with rocks. I don't have a problem at the finish line, but just as I brake the car down to a stop from about 40mph it starts to rev up. Last race it revved to about 3500 and then died. Sounded exactly like hitting the fuel shutoff. I am assuming that the fuel is sloshing to the front of the tank and starving the inlet.

-Brian

 

The pump saver pressure seems a little low to me , is it plumbed back to the tank . or the hat block ?

 

Bingo..........like 30 PSI !
most don't have that kind of pressure available to check it properly, yes the safe bet is to plumb it back to the top of the hat block.
True Story:
First pull on Ralph's flowbench, Ralph doesn't bother to cap the pump saver valve 'cause "that pump won't make big pressure", start the run and that honey opens about 150 psi and pisses straight across on the hood of Ralph's girlfriend's brand new car, of course, just as she was opening the door carrying out the laundry basket!!
Talk about "getting the LOOK"

 

pump saver seems low, I run around 200 or so, and run it back to the block.

 

My pump saver is plumbed back to the tank. When you say run it back to the block, where do you attach it?

 

remove the plug in the top of the hat block and get a fitting that is orb to -6 and plumb a line from the pump saver to the top of the block.

 

This happened to my son while driving my altered. We were at a 1/8 mile (extremely short shutdown) outlaw track, testing and tuning the shocks. The adjustment screw vibrated down and held the butterflies open. He panicked (didn't hit the kill switch) and run out the end through bushes, fences, dirt piles, etc. It wasn't pretty

 

Idle speed screws on butterflies rotating in during run? (Guess how I know about this)
-Brian
This is not the case, nor is frosting the butterflies. This is a lean condition that started after we changed blower, barrel valve and pump.

 

Can you explain why I need 200# on my pump saver? My fuel pressure is in the 140 psi range.What will plumbing it back to the hat block do? Thanks for your help.

 

Could the geometry from the butterfly shaft to the barrel valve accidently got out of wack upon the reassembly?

 

Could the geometry from the butterfly shaft to the barrel valve accidently got out of wack upon the reassembly?
Nope, the geometry is correct. I know this because it was wrong and was pointed out to me before we ran it.

 

kenny,

It was explained to me that you want the top poppet on the "k-valve" to be routed back to the top of the hat nozzle distribution block so that when the runs over and you lift out of the throttle/ slam the butterflies shut and spike the system, that valve will open and send that rush of pressure back to the dist. block and thru to the hat and do two things, First it will cool the blower and keep it from spinning dry thus saving your strips, second it will flood the engine and help combat the leaning out and the high idle.

To be honest mine is at around 200 lbs because that is where the owner of the engine had it when he ran it and i have never changed that combo. The rule of thumb that I have been told is to run it about 20 to 30 lbs over your peck pressure at a bare minimum.

Now someone with more knowledge than I, could give you a more technical explination of what the science is behind it.

Let me know if you would like any more of an explination
Bob

 

thanks Bob, that is what I figured and it makes good since to me.

 

not coming back to idle

kenny check to make sure that your fuel shut off is not closing part way down on the run. it will cause lean condition and hi rpm in the shut down area. you may need a detent or a spring on the cable to keep it from closing.
good luck steve