Fuel filter location ???

[hunt2elk]

Any thoughts on installing the fuel filter before the pump? I'm getting set to route the fuel line on my new 451. I installed a new 3/8" sending unit as well as a 3/8" front to rear line. I picked up the same pump I used on my Charger. This is the one with a 5/16" female thread as the output and a 3/8 tube for the inlet. On the Charger a short 5/16 hard line goes between the pump and fuel separator, but I am not running a return line on this car. Thinking of using a 5/16 to 3/8 reducer fitting and bending up a 3/8" line from pump to the Holley carb. Then the only hose I need is between the main line and the pump, which is where I would put the filter. Is this a bad idea? Just thought it would eliminate a couple of hose connections and also get the filter out from behind the alternator.

 

[lewtot184]

never put a fuel filter on the suction side of a mechanical pump. a 100 micron filter can be put on the suction side of an electric pump, but i don't have a warm fuzzy about any restriction on the suction side of any pump.

 

[clazar]

Everything I've heard is to let the gas push thru the filter. Not to pull it thru it.

 

[hunt2elk]

Glad I asked. Guess I will put the filter in it's normal location.

 

[lewtot184]

cellulose filters were never designed to be used on the suction side of a pump or used in a vacuum. a mech pump will pull anywhere from 15"-19" of vacuum, less than half an atmosphere. the fuel will vaporize before it goes thru the pump and the filter may come apart.

 

[747mopar]

I asked the same thing, I was told the strainer on the sending unit will get anything big enough to effect the pump out and to just put a filter on the carb feed line which is the way I've been running it. I came out of my pump with a 3/8" AN fitting then used braided line up to a Summit inline billet filter (also AN fittings) and back out with the same braided line to the carb. I can take a pic but it works out nice with a bracket holding it out clear of the headers.

 

[Propwash]

There's plenty of in-line filters you can buy that are not paper/cellulose, but fine screen/mesh down to 20 Micron, and will easily out-flow GPH capabilities of your mechanical fuel pump. You'd could install those before the pump, but like Dev mentioned, your sender screen/mesh should weed out anything big enough to damage the diaphragm in the pump. I wouldn't install a cellulose filter before the pump either, so adding a filter before and after the pump seem's pretty redundant. That is unless you're running some real serious power & moola under the hood. Guess it would be a cheap enough insurance policy for $20-30 bucks, but sure seem's like it would be over doing it....

 

[hunt2elk]

I wouldn't install a cellulose filter before the pump either, so adding a filter before and after the pump seem's pretty redundant. That is unless you're running some real serious power & moola under the hood. Guess it would be a cheap enough insurance policy for $20-30 bucks, but sure seem's like it would be over doing it....

I am just using 1 standard filter, not trying to use 2. I'll put it between the pump and carb and call it a day.

 

[Propwash]

Sounds like a good plant to me Joel. I do the same thing as well.


Happy Plumbing!

 

[Dako]

The factory location for the fuel filter on my '72 Dodge pickup was prior to the mechanical pump. Never had an issue.

 

[66chargerpat]

If your Holley is a dual feed, you can use the filters that go in the bowl fittings. They look like brass, but they filter just fine. It look a lot cleaner too.

 

[hunt2elk]

If your Holley is a dual feed, you can use the filters that go in the bowl fittings. They look like brass, but they filter just fine. It look a lot cleaner too.

Already pulled those out, and will just run the on cannister style inline.

 

[lewtot184]

those small moraine sintered bronze filters in the float bowls aren't a bad idea. they're not restrictive, 40 micron at best, and being spring loaded they'll bypass fuel if clogged up. i use them.

 

[hunt2elk]

those small moraine sintered bronze filters in the float bowls aren't a bad idea. they're not restrictive, 40 micron at best, and being spring loaded they'll bypass fuel if clogged up. i use them.

Well there is one fact about this hobby - everybody seems to have totally different opinions on pretty much everything. The only reason I removed them on this carb is that my engine builders Dad (who does the dyno tuning) says he always removes them, and has for 40 years. Then I was talking to a buddy of mine a couple days later and he said he always removes them also. He said he has heard of them plugging up, leaning out the motor, and causing damage. Now I really don't know what to think of them. I still have them installed in my Charger, but was going to take them out. Maybe I will leave them be. :thinker:

 

[Propwash]

Well there is one fact about this hobby - everybody seems to have totally different opinions on pretty much everything

Hehehehehe.......No doubt huh Joel. Ask one question, get 5 answers. It's all about reading between the lines amigo.

 

[lewtot184]

Well there is one fact about this hobby - everybody seems to have totally different opinions on pretty much everything. The only reason I removed them on this carb is that my engine builders Dad (who does the dyno tuning) says he always removes them, and has for 40 years. Then I was talking to a buddy of mine a couple days later and he said he always removes them also. He said he has heard of them plugging up, leaning out the motor, and causing damage. Now I really don't know what to think of them. I still have them installed in my Charger, but was going to take them out. Maybe I will leave them be. :thinker:

it's unfortunate that this type of advice is handed down decade after decade. i would challenge them if they've had first hand experience with "plugging and leaning". those filters have a spring that lets fuel bypass even if plugged and if the fuel system is that dirty an inline cellulose filter would "clog and lean" much quicker. just old '60's nonsense!

 

[ilm65]

Aside from the filter issue, my thinking is if you encounter a 5/16" opening anywhere in the routing of your 3/8" line, you've defeated the purpose of going to 3/8" since you've just introduced a restrictor. I'm running two 600 cfm Edelbrocks on my 440 max wedge (A&A manifold) and went with an Edelbrock #EDE1723 mechanical pump with 3/8" inlet and 3/8" outlet; absolutely no fuel starvation at WOT.

 

[hunt2elk]

Aside from the filter issue, my thinking is if you encounter a 5/16" opening anywhere in the routing of your 3/8" line, you've defeated the purpose of going to 3/8" since you've just introduced a restrictor. I'm running two 600 cfm Edelbrocks on my 440 max wedge (A&A manifold) and went with a Carter 100 gph mechanical pump with 3/8 inlet and 3/8 outlet; absolutely no fuel starvation at WOT.[/B]

Well, here is what I am thinking about doing. The pump has a 3/8" inlet barb, and a threaded fitting on the output which accepts a 5/16" threaded hard line. I would run 3/8" tubing up to the carb through a 3/8" filter. The restriction would be the 5/16" output of the pump and the 5/16 to 3/8 adapter. I don't know if it applies to this, but when I install 2 pound pressure lp or natural gas lines in houses, it is quite common for the outputs of the regulators to be a smaller size than the low pressure output line. It seems like it is not so much of a problem if the bottleneck is right at the output of the reg? What is the # for the pump you are using? Will it fit a 400 block?

 

[lewtot184]

Well, here is what I am thinking about doing. The pump has a 3/8" inlet barb, and a threaded fitting on the output which accepts a 5/16" threaded hard line. I would run 3/8" tubing up to the carb through a 3/8" filter. The restriction would be the 5/16" output of the pump and the 5/16 to 3/8 adapter. I don't know if it applies to this, but when I install 2 pound pressure lp or natural gas lines in houses, it is quite common for the outputs of the regulators to be a smaller size than the low pressure output line. It seems like it is not so much of a problem if the bottleneck is right at the output of the reg? What is the # for the pump you are using? Will it fit a 400 block?
View attachment 235986

i would be very concerned about the capabilities of that pump.

 

[hunt2elk]

What would you suggest? Something like this? http://www.summitracing.com/parts/crt-m4862/overview/make/dodge What kind of power is a stock pump good for?