Fuel Pump Tech 101 please read

[docgreen9]

Here is a little fuel pump tech…..

Just a little background. I’m installing a 2004 5.3 in a 9 GMC Sierra. When the fuel pump question came up I read that you needed to use a Delco EP241. To double check this I called S&P and they said also to use a EP241. Just for giggles ( after I installed the EP241 in the tank and truck ), I checked the specs on these pumps. Now what I got were specs from Airtex book where I work at Carquest.

EP241 ( E3210 Airtex) = Flow= 40 gph & PSI = 65-75
Now that pressure reading is right on the head of the pump at the lab and if you take into account filters and lines and lengths, it’ll probably equate to 50-55 psi… should be.

I wasn’t to impressed with those # and did some checking. I went up in years and found the EP381 pump used in the early vortec trucks, cyclones, ect….and here are it’s #’s

EP381 (E3270 Airtex) = Flow = 50-60 GPH & PSI = 80-90
Here again that psi rating is under perfect conditions at the lab and on the head of the pump. It should yield you a 70-80psi in the vehicle.

I called Airtex and talked to their guy Craig there. He confirmed these numbers I have here and inquired what I was working on. I told him and he said.. quote “ you should never use a EP241 on a vortec or LS1 motor” Craig went on to explain that it would work but the pump would be working itself to death to maintain the pressure and that would shorten the lifespan dramatically. He also explained that the EP381’s were manufactured with a new thin magnet design which yielded a lot higher torque that the EP241’s. They were specifically designed to work on Vortec & LS1 style engines. Also he said the current draw on the EP380 would be significantly less than the EP241, less current = less heat=longer life.
The EP241 is designed to work with TPI & MPI and should only be used in this application

I had my pump out fixing a split hose anyway so I went ahead and got the EP381, well our Airtex E3270.

Just wanted to pass along this little tid-bit of information. I know you guys with newer trucks already have high flow high pressure pumps in the tanks from the factory. But maybe this will help others with their modifications.

[RedHeartbeat]

I run the EP376 from a 93 Corvette LT1. It has worked pretty good so far. I may consider your recommendation next time I have a need for one. Then again I bought mine at Autozone and it has a lifetime warrantee. I'm covered for life on that pump. What are the specs on that EP376 pump, if I may ask?

[custom 68]

so guys are these an intank setup? with the modifications I am looking at I will need to go with an external pump. What would you recommend there?
Thanks
Dave

also to add to this. do I need a regulator or is one "built-in" to the fuel rails. I had done a TPI swap and it is part of the fuel rail system.

[RedHeartbeat]

if you use the corvette fuel filter the "regulator" is built into the filter itself. A by-pass returns excess fuel to the tank return line at the filter once pressure is exceeded.