Pre fuel filter questions.

[zwhore]

for those of you efi guys that have installed a prefilter before your fuel pump, what part number of fule filter did you get?

i have bought 2 and my fuel pump cant pull the fuel through it.

thanks

tony

[gnosez]

You need a 40 micron or larger "pre" filter between the gas tank and the fuel pump. Both Mallory (40um-metal) and Holley (100um-plastic) sell them.

[FastWoman]

Resurrecting an old thread here, because I still have no answers to my fuel pump/tank questions (and my thread seems to have disappeared)...

I am told by my radiator guy (who sometimes refurbishes gas tanks) that the Z's tank (at least the one on my '78) has a filter screen in the sump. The sump apparently is this cylindrical thing, about 4" in dia, standing up vertically from bottom to top in the center of my tank. It's impossible to see the filter screen because it is inside the cylinder.

He cautioned me that acid-etching and then epoxy coating the inside of the tank can eat and clog this screen, respectively.

Anyway, I have no idea what the filtration properties are of this screen, but would this not be an adequate pre-filter prior to the fuel pump?

Thanks!

[gnosez]

No.

Can you verify the size and quality of said screen (a screen I have never seen myself)? Are you willing to trust your engine to said screen? Do you have the necessary emergency kit (in the car) if said screen fails to protect you (tools,spare parts, AAA card, cell phone)?

These are the sort of questions that had BP actually raised them and considered a realistic response, that big old oil leak would likely not have happened.

Similar to driving on the road or a race track, looking ahead is very important....

[Shade133]

ive never heard of a screen in the sump. that seems to be bad engineering.. once its clogged, what you got to buy a new tank? or is there an actual way to take it out? if so, take it out and put an external one.

Nick

[steve91tt]

I simply grabbed a universal filter from the autoparts store and put it on the outlet from the tank before the electric pump. Quick, cheap insurance. Nothing but gas should get to the pump.

[Shade133]

I simply grabbed a universal filter from the autoparts store and put it on the outlet from the tank before the electric pump. Quick, cheap insurance. Nothing but gas should get to the pump.

thats what i thought. i thought they didnt put those screens in the tanks until the later years where the pump was actually in the tank?

[FastWoman]

@Gnose: Well, the car has run very well for over 3 decades now with the stock design, so I don't think it's as dire as all that! But yes, I always carry tools and my AAA card. I think those are required items for any antique car -- and really any other car.

@Nick: No, there's no way to remove the screen or even to see/look at it without cutting the tank open. The radiator guy insists there's one inside, because he says he's refurbed a couple of Z tanks and even modded one for racing. I have no reason to doubt him. He does that sort of work. He had a late 60's vette and a nice 40's Chrysler in his garage when I was there.

The inside of the tank frankly looks amazingly good, aside from a couple of very tiny spots of rust near the drain hole. It's hard to believe the tank is 30+ years old, until you look at the surface rust hiding under the paint on the outside (about what I'd expect).

Anyway, for an external filter, I'm thinking I need a high-flow design, and not a filter meant for a carbureted engine, right?

[gnosez]

40 to 100 micron regardless of EFI or carbs....

[FastWoman]

Thanks!

[Shade133]

ya you throw a carb one in there the high psi will eat it up. happened to be one my first Z. lesson learned.

[gnosez]

Neither the Mallory or the Holley will be eaten up (I run a Mallory Comp 110 pump). The filter is on the suction side.