Where is the best places to put inline filters?

[hienz]

Changing my 75 911s to Webers, and already had new fuel tank replaced. Also removed original fuel pump and installed new fuel pump to get correct fuel PSI for Webers.

You keep the original fuel filter and installed two inline fuel filters to keep all dirts from go in the Webers? or

You removed the original fuel filter then add two inline fuel filters?

Where should be the best places to install inline fuel filters?

Thank you so much in advance.

[juanbenae]

in my 78 I maintained the stock fuel filter prior to the regulator as it was actually the easiest plumbing opportunity, then used another after the reg prior to each bank.

my current 75 below I went away from the stock filter using a large, clear wix in line just prior to the regulator and again one smaller wix unit prior to each bank. my tank was surprisingly clean when I got the car 2.5 years ago but the clear inline prior to the regulator allows me to actually see how much crap the filter collects monitoring when to change.


if you are looking for something more discrete I guess you could place the pre-regulator inline down by where the lines leave the tunnel, but I don't mind seeing it in the motor compartment. the two prior to each bank are standard and really are more about function over form.

[hienz]

Thanks Juan. I assumed to retaining original filter like your 78 required special fitting come out of the filter before it hooks up to regulator. To eliminate original filter just connect inline filters to the lines. I like to try both options and see witch is best for me.
Did you change out original fuel pump on your 75?

[juanbenae]

Originally Posted by hienz

Thanks Juan. I assumed to retaining original filter like your 78 required special fitting come out of the filter before it hooks up to regulator. To eliminate original filter just connect inline filters to the lines. I like to try both options and see witch is best for me.
Did you change out original fuel pump on your 75?

yes, on the 75 I removed the entire OE fuel pump in the drivers fender well relocating a carb, low pressure fuel pump to the smugglers box. I did have to get creative with some plumbing fittings to attach the line leaving the new pump to the existing tunnel line and again from the tunnel line at the motor compartment to the regulator.' many suggest pulling new fuel lines through the tunnel, mine looked good so I maintained them.

the 78 set up was 10 plus years ago so I don't remember exactly what I did. best I can recall I used the existing line from the OE filter that supplied the CIS system again with some plumbing fittings to transition to the fuel line prior to the regulator.

regarding using the high pressure pump of the CIS system. I did so at the outset with the 78 but a relatively new fuel pump failed with in a couple years. the regulator got the pressure reduced fine, but my theory is that even with the return line the pump operating on such a deadhead to reduce the pressure caused it to fail prematurely. I ended up swapping out the CIS pump for a 3.2 OE pump in the paddock on a race weekend cause that was all jerry woods had in his transport. the 3.2 pump worked for another three years while I owned the racecar.

[Trackrash]

I don't know why the original filter wouldn't work. I would just replace it with a new one and make sure the fuel lines are CLEAN. I have only a Bosch fuel filter on my car and it works fine.

Are you replacing ALL the original rubber fuel lines?

[hienz]

Hi Gordon
I replaced all new original fuel lines.I know there are 4 filters at the Webers, but I would like to installing clear inline filters so I can see how dirty fuel entering the Webers and also know exactly there are fuel coming in to the carbs. Since my inline filters are so small, I should retain the OE filter then from there fuel can enter fuel regulator to get 2.5PSI.
How do you connect the fuel line overflow so that the extra fuel will return to the gas tank? (the fuel regulator has two fittings for the two Webers and one more fitting for returning of overflow fuel. The OE filter has one fitting for fuel to enter and on the opposite end there is one fitting for fuel exit the filter.)

[juanbenae]

Originally Posted by Trackrash

I don't know why the original filter wouldn't work. I would just replace it with a new one and make sure the fuel lines are CLEAN. I have only a Bosch fuel filter on my car and it works fine.

Are you replacing ALL the original rubber fuel lines?

on my 78 it was simple to run the OE line described above from the filter in the motor compartment to the regulator with the original line. as I recall it only required one of earl's fittings threaded into the PMO pressure regulator to mate up. the 75 with all the fender well fuel pump lines to the filter I recall it being simpler to start from scratch removing the original filter assembly from the mix.


the fly in the ointment with even a carb friendly low pressure pump in the 75 is the smaller diameter return line compared to the 78. with the smaller return line even the carb lower pressure pump required the PMO regulator to be squeezed down at the bottom of it's adjustment to get 3.5PSI.


you have a 71 rash. is the fuel filter plumbing consistent with the middie and SC CIS cars?

[RWebb]

get a big Racor with the water seperator and put it where you can get to it easily to drain it

... no, I haven't done this, but I know I should...

[BoxsterGT]

I can supply Crimped hose that has both Metric and AN-6 for those who are planning aftermarket filters or FPRs.






I also have custom fittings for the Factory Filter when used with aftermarket components downstream.

Len.Cummings at verizon.net

[hienz]

Originally Posted by juanbenae

on my 78 it was simple to run the OE line described above from the filter in the motor compartment to the regulator with the original line. as I recall it only required one of earl's fittings threaded into the PMO pressure regulator to mate up. the 75 with all the fender well fuel pump lines to the filter I recall it being simpler to start from scratch removing the original filter assembly from the mix.


the fly in the ointment with even a carb friendly low pressure pump in the 75 is the smaller diameter return line compared to the 78. with the smaller return line even the carb lower pressure pump required the PMO regulator to be squeezed down at the bottom of it's adjustment to get 3.5PSI.


you have a 71 rash. is the fuel filter plumbing consistent with the middie and SC CIS cars?

My fuel pump has 3 fitting and my regulator has 3 fitting also. but the Oe filter has one in and one out fitting. I have to find good drawing how they inter-connect.

[hienz]

Originally Posted by BoxsterGT

I can supply Crimped hose that has both Metric and AN-6 for those who are planning aftermarket filters or FPRs.






I also have custom fittings for the Factory Filter when used with aftermarket components downstream.

Len.Cummings at verizon.net

Nice to know where to find these custom hoses. Are your hoses could handle Ethanol because all of our fuel in USA/ California are Ethanol added?

[hienz]

Originally Posted by RWebb

get a big Racor with the water seperator and put it where you can get to it easily to drain it

... no, I haven't done this, but I know I should...

Racor filter with water seperator. I must google it. Thanks

[Trackrash]

Originally Posted by hienz

Hi Gordon
I replaced all new original fuel lines.I know there are 4 filters at the Webers, but I would like to installing clear inline filters so I can see how dirty fuel entering the Webers and also know exactly there are fuel coming in to the carbs. Since my inline filters are so small, I should retain the OE filter then from there fuel can enter fuel regulator to get 2.5PSI.
How do you connect the fuel line overflow so that the extra fuel will return to the gas tank? (the fuel regulator has two fittings for the two Webers and one more fitting for returning of overflow fuel. The OE filter has one fitting for fuel to enter and on the opposite end there is one fitting for fuel exit the filter.)

In my case I just ran the supply and eliminated the return. I know there are two ways to plumb carbs depending on the type of pump and regulator. I have a Facet low pressure pump and just the Bosch filter, no issues. If you are running a regulator, you will have to plumb according to the type of regulator you have. I'm not saying my way is the best or only way, just that it has worked for me for decades with no issues.

[911pcars]

If possible, suggest locating your filter(s) and pump for easy access for repairs, replacement and/or maintenance. Notice the ball shut-off valve that avoids having to drain the tank for FP service. Install a relatively coarse see-through filter before the pump to observe potential tank debris. Install other inline filters where you can easily R&R.

Here's a current example. Future plans include moving this assembly into the trunk area (914-6).


Also suggest installing a fuel pressure gauge close to the delivery location (FI rail, FP reg. or carbs) to confirm/observe the correct fuel pressure is available. If possible, mount to chassis to avoid excessive vibration and hose fatigue. If you're paranoid about FP, install a remote display pressure gauge in the cabin (avoids potential combustion activity next to the cup holder).

Sherwood

[hienz]

Hi Sherwood
Your fuel pump is OE which one in and one out fittings. I replaced mine pump with 3 fittings (one return one in and one out)

[dannobee]

Originally Posted by hienz

Racor filter with water seperator. I must google it. Thanks

We used Racors on diesel engines and boats. They're pretty big and I don't know how you'd fit them near the gas tank on a 911. It would definitely work though.

The old standard for carbureted race cars has always been the Fram HPG-1. They quit making it in 2015, but there are copies now available. Plumb it before the fuel pump. Change the element every 2000 gallons of fuel. It's the only one you'll ever need. It's probably been installed on hundreds of thousands of race cars.

https://www.summitracing.com/parts/sum-g1507/overview/

Or https://www.summitracing.com/parts/tfs-23006

[targa44]

Sherwood,

Would you reference the coarse filter and ball valve? That's a nice arrangement.

thanks,

[911pcars]

Originally Posted by targa44

Sherwood,

Would you reference the coarse filter and ball valve? That's a nice arrangement.

thanks,

The filter is the commonly available, see-thru type from your local FLAPS or internet. The 65 micron filter is replaceable. The ball valve was sourced from either eBay or McMaster-Carr. Brass hose adapters, 1/8"NPT x 5/16", can be sourced from most hardware or plumbing sources. You can brighten things up with AN hose and aluminum AN fittings and hose adapters. Hope this helps.

Sherwood

[BoxsterGT]

heinz -

My Hose is E-85 Rated and available in plain or Braided SS.

Here is an adapter Hose I made up for an early 911 that original CIS Filter was NLA and now uses a later version.....



Hope this helps.

Best way to reach me by email, Len.Cummings at verizon.net

[RWebb]

IIRC, people usually mount the Racor units on the firewall