So i am in the final stages of getting my T/A put back together..5 plus yeas later after i blew the stock motor. Its been a long road and a good learning experience...and pricey..lol. So i got a couple of questions and planning to run 2- 255lph Walbro pumps to feed hopefully approx 700 hp to the wheels. So the fueling thing and wiring i feel like a beginner at even tho i been wrenching for 20 years...so dont flame me to hard. I bought a kit a while back that has the extra walboro pump (already had 1 in tank from previous boost on old ls1) with a "Y" connector for the 2 pumps from the "bucket" to merge into the topof the housing. Now i was measuring with a drill bit after the 2 pumps merge ,before it goes up and out of the housing ( top of fuel pump assembly) it only measures at 13/64" and where the fuel line connects to (outside top of tank) measures at 15/64". My question is.. has anyone taken a 1/4 inch drill bit to hone both of these out for Less restriction for both of these pumps? Is this a no no so you keep higher pressure?? Or? Also I have seen posts that you need a different regulator in tank for something pushing out over 650 rear wheel horsepower? Where do i get this different regulator if i need one? Thanks...you guys always have great info. I did read the Mighty Mouse sticky but still lost a bit on the regulator bit..

 

I am the only one that has ever thought about honing the outlets from the fuel pump?

 

The restriction you are seeing could be the part of the pump that allows it to build pressure. There is a difference from a transfer pump and a pressure pump.

 

ok thanks..so i will just assume that it a no no to hone the smaller 13/64 inlet after the pumps to at least match the outlet the fuel line hooks to..(?)

 

I think I jumped over some or read this wrong. I was thinking you were talking about the outlets of the pumps. They often have like a cross or other thing in the outlet that looks like a restriction. I can tell you this for sure you can flow 450lph through a 5/16" line. It does move faster than you would want to travel passed the injectors, but it will carry the volume with minimal pressure loss. I'm using the old 5/16" emissions line as my return for my 450lph pump. You can use this to get the answers to your questions and learn answers to things you didn't know you wanted to ask here.

https://www.lmengines.com/fuel-line-calculators/

 

THanks!

 

Welcome.