Poppet Question

I just got a hemi with a littlefeild and a enderle big and ugly i would like to get some info on it does any one know why they would have two poppets on the return line from the valve to the pump? And why would they put the return on the outle side of the pump? Why does the hat block have two lines running to it from the valve? I always have ran screw blower with different setup and this is all different and the pump says 110990 on it does that mean its a 990 ?

 

Sounds like the pump is a 990. If you pull the cover off the pump, measure the length of the center rotor, if it is a 990 the rotor is 0.990 long.

For the fuel system, there should be an idle check on the front of the barrel valve (same surface as the inlet from the pump) which should be set to 6 or so psi, and should run back to the tank.

There may also be another poppet pointed in the same direction that is your pump saver valve, it should be set fairly high, probably around 200 psi, and can run back to the tank, or back into the hat fuel block. This should only open when you slam the throttle shut.

Behind the barrel valve (on the outlet side towards the hat and port nozzles), there is usually a high speed poppet teed into the line, sometimes there are two. This high speed is set to about 50 or 60 psi, depending on how soon you want it to open. A 60 psi poppet will usually open about 100 feet off the starting line, if the car is a dog you can lower the pressure to liven it up, if it smokes or shakes the tires about 60 feet out, you can raise the pressure to see if that helps. This line should also go back to the tank. Make sure there is a jet above the poppet, usually somewhere between a .050 and a .080, depending on your fuel system.

These lines can all run into a fuel block off the side of the pump, but the fuel shutoff must keep them isolated from the fuel flow while the engine is running. There must be a line coming out from this block that goes back to the tank, and this line must be big enough to handle the volume of fuel that the barrel valve and high speeds generate.

 

What about the two poppets on the idle check? Is it better to run the pump saver to the hat or back to the pump?

 

I like to run the pump saver back to the hat, I believe it keeps the rotors lubricated as the motor is shutting down.

You would have to send me a picture of your setup, I'm not sure how you can have two poppets on the idle check.

My e-mail is ksitko@shaw.ca

 

The so called 2nd idle check may be a pump sizer (I assume its a complete 2nd line, not 2 idle checks in a row).

If its 2 in a row, one fter the other, then I can't help you.

All the best.

 

Maybe the guy needed to splice two line's together and used the poppet body as a connector, take it apart and see if there is a spring and poppet inside on both of them, or maybe the guy was just messing with his competition's head.