Fuel filtering questions

[MFalkinham]

I've been following the threads regarding how the HPCR systems are more sensitive to dirty fuel. It appears that most TDR members feel that it is important to change the fuel filter on a regular (15k?) basis to protect the pump and injectors, and I agree. However, won't our fuel filters actually remove more contaminants the dirtier they become? Granted, the throughput of the filter will become more and more diminished, but won't the efficiency keep improving up to the point of being totally clogged? I'm not saying we should never replace the filter, just trying to determine if there are advantages to leaving it in longer?



Another question I have is regarding a Frantz TP bypass filter like Gary - K7GLD is using. We have those two unused vents on top of the fuel tank that would normally be connected to the evap system on gas powered Rams. I'm wondering if we could plumb a bypass filter along with an inexpensive external fuel pump in series between these two vents, with one vent hole being used as the feed line and the other as the return. Basically, this could provide constant filtration of the fuel inside of the tank anytime the truck is running. It wouldn't totally solve contamination problems, but it might remove major debris from the tank before they have a chance to make it to the main fuel filter. Would this work?



- Mike

 

[rbattelle]

Your ideas are intriguing. Yes, it's true a filter will filter "better" after it's used than it did when new. But as you point out, there's a tradeoff between flow restriction and filtration. I've been searching for an appropriate fuel filter change interval since the truck was new. I've tried 200, 250, and 300 hours. I'm getting close, and I will replace the current filter when it's got 350 hours on it. I'll be happy when I find an interval that leaves the filter with a "good amount" of dirt on it.



Your idea about using the fuel tank ports is interesting. But when would you run it? You'd want to run it before running any fuel through the system, which means a LONG wait at the fuel pump. The other problem is that although you'd end up with excellent clean fuel, it would still have to travel through the stock pickup and lift pump, both of which might make the fuel much dirtier. Ideally, the filter would be the last thing in the fuel line before the injector pump.



It's good to think about these things... it encourages innovation.



-Ryan

 

[MFalkinham]

Your idea about using the fuel tank ports is interesting. But when would you run it? You'd want to run it before running any fuel through the system, which means a LONG wait at the fuel pump. The other problem is that although you'd end up with excellent clean fuel, it would still have to travel through the stock pickup and lift pump, both of which might make the fuel much dirtier. Ideally, the filter would be the last thing in the fuel line before the injector pump.



-Ryan

You made some valid points, Ryan. I envisioned this system being powered off of the ignition switch, and the bypass fuel pump being powered whenever the main lift pump is running. This setup wouldn't help immediately after filling the tank, but as the tank gets emptied the fuel will become cleaner and cleaner. I figure that every little bit helps, and the TP filter media would be very cheap to change frequently. I'm wondering if these Holley pumps would work; the red one is only $95. http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1497&prmenbr=361



As for the fuel taking on debris after it enters the stock fuel lines, I don't think this is a significant problem after the fuel system has been used for a few thousand miles, but I'm just guessing and might be totally wrong.



- Mike