Factory fuel tank mods..?

[K.Kiser]

I have a factory Moeller fuel tank with the usual top feed, and I'm assuming a ball valve... Can the ball be removed from the factory 90 degree fitting and have enough flow to support a high effort V6, or will the whole pick-up system need to be replaced... I have the factory Bosch pump for the hi-po 2.5, and I also have a WIX fuel separator... Thanks.

 

[Myron]

http://diamondmarine.com/, very good article on fuel supplies for boats

 

[Sking]

I also have a fuel tank with a top outlet. When I rigged my XB2002 with a 280 I removed the drilled brass 90 degree fitting and installed a 90 AN ell. It is more of sweep or radius 90. I have read that the drilled 90's restrict flow quite a bit. I also did the same thing at the bottom of the fuel rail on the motor.

 

[K.Kiser]

Myron, I've read that article before but didn't see anything to address a top feed set-up, although I may have overlooked something...


Sking, that may be what I'll try... Get Myself some plans for AN fittings and go from there unless I see sign of fuel starvation.. Do You have trouble with losing prime to Your pump..? I have plans to mount My separator before My pump, in terms of fuel flow direction and letting My pump pull through My separator... Thanks both of You Fella's for the replies...

 

[K.Kiser]

OK, I saw the HUGE paragraph about top feed tanks... According to Diamond, all that I really need is the 90 elbow at the top of the tank as SKING mentioned, and a copper stand pipe to replace My plastic screened one... Thank again..

 

[Sking]

I would leave the screen in the pump suction in the tank, it acts as a larger debris filter before the fuel pump, then install a filter after the pump.

 

[K.Kiser]

My set-up has the filter/separator before the pump... I didn't see any preference in the Diamond article about which should/shouldn't come 1st... I think it mentioned about having a secondary filter between the pump and the fuel injector rail, leading Me to think that the separator should be before the pump according to the picture that appears just after "figure 12" in the fuel system 101 article... In other words:

- tank -- separator -- pump -- secondary filter -- injector rail

Have I missed something..?

 

[Myron]

I do not run a water separator, mine is set up just like Diamond has it, copper stand pipe 90 elbow, 1/2" fuel line to the pump 3/8" fuel line thru a wix 33093 filter to the fuel rail

 

[K.Kiser]

I've always been warned that the Bosch pumps are finicky about debris, requiring decent filtration before the pump, do You have a filter of sorts before Your pump.. I've seen some trash in tanks from Gas Station pumps, it scares Me a little...

 

[white03]

Just hooked-up my 280 a few months ago and went through the separator before/after issue. I should state that I also have an in-line fuel pressure gauge just after the fuel rail. What I found is that if I put the separator before the pump I had a very significant drop in pressure at the fuel rail. If I put the separator after the pump I got a "gurgling" sound at the pump. Watching the pressure guage I saw a drop in pressure directly correlating to the "gurgling" sound.

To be fair there seem to be sevaral guys that have the same setup with a separator that do not gurgle. There are also those that have the gurgling. Do a search and you will find a bunch of info.

Like Myron, I decided not to use the separator. Primarily because I had just blown a motor due to loss of fuel at top end. I now check my fuel pressure each and every time I crank her up. Because I have the gauge I can tell if anything is going wrong with my fuel delivery.

If you want to by a brand new separating filter mount and filter let me know. I'll make you a good price.

Bill

 

[K.Kiser]

I just put a brand new WIX separator in the boat today, I hope that I haven't wasted time, money, and a few holes in My bilge... I was just so paranoid about moisture in the fuel because I've seen it before..

 

[Myron]

I have had my setup this way for years and I have not had any problems. Mercury even goes back and forth on the water separator issue, myself I want the least amount of restrictions as posible. With a plastic tank there is a lot less chance of moisture than with aluminum

 

[GFinch]

Allison Owners Forums > Allison Boats > Nice Outboard Motors Best EFI fuel pump? And where to get it?

Trials and tribulations of a fuel seperator.

 

[K.Kiser]

I read the whole link, that's good information... I guess that I really need to just hook the whole shabang up and see if it works... If it works well with the W/S I'll leave it on, if it obstructs or causes cavitation I'll bypass it and put loose micron filter in it's place and the WIX 33093 before the injector rail... I have another question concerning the brass barb fittings that I just bought... The package reads that the fitting "fits 3/8" I.D. hose", but the actually passage hole measures about 5/16", is this correct... The hole looks to be the same size as the hole in the fitting that is on the bottom of the injector rail, have any of You noticed this..?