Engine/Transmission (1998.5 - 2002) Building a FASS

[KOdegaard]

Anyone here build your own FASS?

Ideas?

TIA

Kirk

 

[Cummins4Life]

If the pump in the FASS system proves to be reliable I'd be interested in using it for a solitary pusher and keeping the stock filter/heater setup. Its just too big for me.

 

[rweis]

Sort of:



RACOR 690 w/heater (10 micron)

OEM lp @ tank w/ AN-6 lines to OEM filter & VP

Mallory 4307M post lp



Fuel well filtered and heated if necessary,

OEM lp @ tank,

Mallory 4307M to keep lp bypass valve closed, set lp head pressure, stabilize psi (10 - 12) to VP.



I have NO idea if it removes air from fuel.



Parts ~ $250 + AN-6 (SS) ~ $200 = $450, FASS ~ $560 (I think)



I wanted to choose filter mfg,

ability to change the lp seperately,

ability to set the VP input psi independent of the lp output.



As I understand it:



They filter the fuel

Change the lp

Set VP input psi



AND take air out of fuel (?)



Bob Weis

 

[Ncostello]

I sort of made my own FASS before I ever heard of the FASS. I know I spent as much money on mine. I am however satisfied with the Stanadyne dual filters and my OEM lift pump (latest revision) is doing quite well. I think it will last a for a long time. What you dont see is my intank module... which I removed the restrictive screen mesh from. Basically I have a 3/8" tube to the bottom of my tank which was very clean inside. Any tiny junk that gets sucked up will go to the first filter before the lift pump.



I prime new filters by using an extra pigtail (extended) for the lift pump I have. I just clip it to the batteries, plug it into the pump, and let the pump run for a minute or two. No starter bumps and guaranteed purging of all the air before fire up.



I would like to know what kind of pump the FASS is using. I'd be interested in taking a look at it.

 

[KOdegaard]

Thanks all for the replys



Bob,

Why the post LP mallory? It sounds to me that you are using

it as a regulator, isn't the oem lp fine for 12 to 15lb?

Seems two Lp's is more trouble tham one?



Please do not take this as a flame, just trying

to undestand.

Tnx

Kirk

 

[rweis]

Kirk,



The post lp Mallory is a bypass regulator (I bypassed mine back to the tank vent line). The Mallory is not a pump, it is a bypass regulator.



One of THE MAIN problems with the OEM lp is just what you posted [ 12 - 15 ] psi. The internal bypass check valve is operating and ... ... .....



The problem is the lp bypass check valve ball will operate. The problem with that is the ball MIGHT not reseat properly (eratic and low psi), the ball MIGHT not seat at all (low psi), the ball seat MIGHT fail (no psi).



There have been MANY post about members that took the OEM lp apart after failure to find something lodged in the ball seat. One member had others ship him their failed OEM lp's so he could do a study about what was causing the failures. The conclusion was the primary failure in the OEM lp is the spring loaded check ball valve. There was even a couple of threads about a couple of members that drilled and tapped a set screw into the ball valve chamber to force it to stay closed. Problem with that is you have to drill very precisely and you don't really know where it is from the outside.



The Mallory 4307M is a bypass regulator that I set BELOW the bypass spring pressure so the check ball valve NEVER operates. I think it should stop that ball valve problem permanently.



It also allows you to put in almost any pump because you can set the bypass to whatever psi you want. If you put in a 25 psi pump and you want the vp to have 15psi, just adjust the bypass regulator to what you want. Impossable to overpressure the vp because YOU set the pressure, not what ever the brand of pump you bought is set for.



This is part 1 of how I solve the lp problem.



Parts 2,3,4 are:



2. the nylon coupling between the motor and pump stripping from generally cold (sluggish / gelled) fuel.

3. the vanes of the lp not sliding in and out of their rotor slots smoothly and therefore NOT maintaining the pumping chamber seal.

4. the OEM lp is a good pusher, poor sucker.



Bob Weis





Bob Weis

 

[KOdegaard]

Tnx Bob, now I see, good idea, how is it working so far and

how many miles on this set up?

Kirk

 

[rweis]

Kirk,



Not much time on it yet, about 1500 miles. Time will tell. The pre & post filter psi's are holding just fine though, 13 - 12 pre, 12 - 10 post.



I have done some wot's, pulled my 5er where I left it in wot for 20 seconds (32#, 1200*), min post filter is 10, min pre filter is 12.



Before when it shifted from 3rd to OD I would see a psi spike post filter to about 16 - 20 for a second or two as the psi in the vp was high and the rpm dropped abruptly as the shift happened. Doesn't happen now, which I think is a good thing.



The fuel psi's are totally stable. My intent is to keep the lp turning smoothly, with no more than 13 psi head pressure, the check valve ball stay fully seated. Seems to be working.



If and when the lp starts to fail and the motor looses power I can just readjust the bypass, probably will just change the lp. Should be interesting to see how long the lp will go humming along. I bet for a long time.



Another part of the puzzle is "stiff fuel" or debris stressing the lp motor nylon sleeve that connects the lp motor to the pump. I have a RACOR 690 10 micron water seperator filter with the fuel heater and use Stanadyne Performance Formula for that eventuality. The lp should never see anything but treated fuel of the right temperature with a very low pour point and very high lubricity. Keeps the pump rotor vanes well lubricated so they can fully use the centrifugal force to stay seated against the pump chamber walls and maintain pressure.



The Stanadyne also coats the tight tolerance VP parts so when you have had high demands on the VP and good flow for cooling and lubricity, then drop the demand to idle with little flow and little lubricity there is more of an anti friction coating on the internals to the VP than just the fuel. At least my take on it. I got this from the TDR chapter meetings at VP pump rebuilders. Also the RACOR makes sure NO water EVER gets to the VP.



We had meetings at pump rebuilders and their answer to high pressure pump failures was the same over and over, water damage & lack of lubrication. The RACOR blocks water. I think the OEM fuel filter does not actually block water, but tries to shed water. With 2 water filters my chances are higher that I can get ALL the water out. The Stanadyne helps with the lubricity.



Of course move the lp to the tank with AN-6 or larger lines and NO right angle fittings, NO banjos, ONLY full flow smooth fittings.



Unique, nope. Many have done the same thing. The FASS "takes the air out of the fuel". Not sure how to do that. Might not be able to do that. Might be of consequence, might not be.



Time will tell,



Bob Weis