Does anyone know what the operating pressure for a Holley HP carb should be? I would like to know the prefered idle pressure, and the W.O.T. pressure. I have heard 5 to 6 lbs at W.O.T.? What is too much pressure at idle, to cause it to over flow? I will be running a stage one pump, with the return line blocked at first. Was thinking of a Mallory 110 pusher pump if need be. Do I need a regulator, or will this set up be within spec for 1000 HP? Motor will be in the 530 to 550 hp range, @ 5600 to 5800 rpm. I am keeping my fingers crossed, should be done very soon. Just waiting for T/A to put a level 2 port job on their Stage 1 SE heads for my builder. Thanks for any insight. Regards, John. :TU:
7-8 psi all the time. could try 9 but may push the needle off the seat. i would go with the mallory pump. the stage one pump dosent supply enough fuel for that horsepower level. if you want to stay with the mechanical pump, would recomend our billet pump. http://trishieldperf.com/prod04.htm
Thank you very much for your response Rick W.! I would like to ask you three more questions please? 1) If I use the Mallory electric and the stage 1 pump, is it o.k. to keep the return line plugged, or will the pressure be too high? 2) If I go with your pump, can I still use my stock 3/8 lines from the tank and 3/8 brake line type lines from the pump to the carb? I am trying to keep a bit of a stealth look. I don't want to use braided lines there. 3)Will it clear a Cloyes roller chain, without modification as well? Regards, John.
I use a stock Stage 1 mechanical pump with the return plugged fed by a Mallory 110. I modified the stock pick-up by soldering in a 3/8" pipe swept toward the back, no sock, stock lines. Probably has room for improvement, but it looks stock and seems to work well. If you don't have a TA timing cover, you may have to elongate the fuel pump mounting holes to push the pump forward a bit to clear a double roller chain. HTH's
Thanks Bob. I assume that you are refering to your pickup in the fuel tank. That is an excellent idea. As long as you are not having pressure issues with your fuel return line blocked, I will keep it blocked. My motor will have a T/A cover, so it looks like I will have some wiggle room if I decide to go that route. Thanks very much for your input. Regards, John.
I`m running about 5-6 lbs. on my 464 with a TSP pump but i`ve regulated it to that with a regulator,7-8 or 9 seems alittle high to me,i`ve never had any issues running 5-6 lbs. Thanks
Thanks a bunch for your reply George. I assume you have stock lines from the tank, and the TSP pump works for you. That is what I wanted to know. thanks again. Regards, John. :TU:
No John i dont have the stock lines,i have a steel braided line from the tank to the pump,i think its a #8 line but stock lines should work fine only thing you need to get is an adaptor for the fuel pump,im sure Jim from tri-shield would hook you up and tell you what you need to do or get to hook it up with stock lines,good luck. Thanks
