This is what I would like to do for a lift-pump setup. I'd run a single FM100 with lift pump all the time and have the carter hooked to switch inside cab or perhaps hobbs switch later on and only run it when I want to. Is this setup ok or would there be problems with it?

http://home.comcast.net/~tophog/duramax/images/Liftpump.jpg

Tophog,

With no bypass around the FM100, what will happen if that pump fails? Will you be stuck? or will the OEM pump be able to pull through the dead pump?
I am also wanting to put in a lift pump, along with extra filtration, I am patently waiting for the new pump Kennedy is getting close to putting on the market. This new pump will allow the truck to keep running if it fails......

looks good to me, whats the GPH and Pressure on that Carter

I'm not positive without looking it up on Summit's web site but it's the one everyone is using, including the SD setup I believe. I think it's rated at 100gpm and 6-8 PSI or thereabouts.

Here's a pict of what I have so far. The Racor will be replaced with the FM100 and built-in lift pump and I'll run a 6" 5 micron filter on the FM100. I was going to just go as-is (with Racor filter, no FM) and run the Carter full time but thought it would be better to have a continous, longer-life LP in addition to a Carter for when I want the extra volume. I would have went with SD's setup but I am getting the FM100 almost for free (via a relative) so I'll have about $200 in the complete setup.

I already have everything wired, etc. Just need to figure out what I want to do with fuel lines as right now I only have the supply line cut in one spot from where I installed the Racor 2 years ago and if I want to use it as-is I'll have to loop back the supply coming out of the end of the carter to where the fuel line is currently cut. It's either that or cut a section out which would greatly simplify plumbing in the Carter assembly and result in less hoses, etc.

http://home.comcast.net/~tophog/duramax/images/lp.jpg

looks good to me, whats the GPH and Pressure on that Carter

Running those in series may produce too much pressure. What's the combined operating pressure of both pumps? Thats what you'll be seeing.

From what I've read the FM100 is around 5-7 at idle and rated for 80 gph ... I think the Carter 4600 is around the same and rated for 100 gph. I will only be running the Carter when I want to via switch. My goal is to give the Extreme as much fuel as it needs in the 200 mode which has been my problem without a LP.

If running them both results in 12 psi or so at WOT I'd be happy and think the FM100 will be fine in the 80 hp mode by itself. I guess I need to hookup a gauge after I get the FM100 installed to see where I'm at. I plumbed the Carter today and went for a spin. It made a world of difference on WOT runs ...whereas before it would fall on it's face after 3rd gear...oh, lots more smoke too ...not that there wasn't plenty before. :)

The FM100 does not flow 80gph.....only 40. If you look at all the info a little closer, you will see that the filter itself is capable of 80gph, but the pump does not flow that. 40gph at 6-8psi is the capabilities of that pump. Hope this helps.

OK, Now I understand.
Something else worthy of consideration would be to use a check valve in place of the normally open ball valve. That way you would always be ready for action without having to go under the truck. Just switch on the carter or let the hobbs take over where set. :)

Thanks for the clarification ...80 psi sounded a little high to me after thinking about it ...and knowing others are running twin FM100's in parallel to get enough volume. I must have confused the filter spec with the pump spec. I think the 40 will be better based on the fact I'll be running both pumps at times.



The FM100 does not flow 80gph.....only 40. If you look at all the info a little closer, you will see that the filter itself is capable of 80gph, but the pump does not flow that. 40gph at 6-8psi is the capabilities of that pump. Hope this helps.

Hmmm... Doesn't look like it will work. The Carter won't do anything. You need a "one-way" in the bypass loop on the Carter.

I thought the same as you McRat, but the Dodge guys are putting a stronger pump in front of (before) their stock lift pump and it's working fine for them......they are using the Carter as well. If it were me, I would run the Carter parallel to the FM100 and let her eat. The FM100 is being used by quite a few and being designed for diesel, it will last quite sometime....I believe Sdaver had one on his truck for 70,000 or so and it was working fine when he replaced it with the FASS......just my opinion though. I doubt very seriously that both pumps will fail at the same time.....although stranger things have happened....

I've been under the impression the FM-100 is NOT flow through. Is this correct? If so the Carter will be restricted to the same 40 GPH.

I guess I need to do more homework then just reading posts on here. I'm going to call Standadyne tomorrow. I know I read someone saying the FM100 would flow on failure ...if not, then I won't be running it and will run the single carter and my racor filter ...where I'd just cut off flow via the bypass with the ball valve until the Carter failed. I should have verified the FM100 lift pump operation before "assuming". My bad. I do not want to be stranded or under the truck at night in a rain storm trying to bypass fuel.

The primary reason I wanted the FM100 with lift pump was it would allow me to run a continuous, low volume LP and use the Carter for the extra volume when I wanted it. If the FM100 doesn't flow on failure my plan is FUBAR.

I can also see where the Carter is pumping in a circle without a check valve.

Back to the drawing board.... :(

I understand what you are referring to now as "flow through" ...meaning the pump itself does not restrict fuel flow to the 40 gph. So "flow through" and "if" the pump passes fuel on failure are completely different things?

I guess I should have paid more attention in science class :)

I've been under the impression the FM-100 is NOT flow through. Is this correct? If so the Carter will be restricted to the same 40 GPH.

I think you're on the right track and what you want to use will give you everything you need.......just the layout that is questionable. Like I said before, the FM100 being designed around diesel will last quite sometime.....I don't think it is designed to be a flow through when it fails, but the pump on our trucks is one strong mutha..... I would just run them in parallel and put the Carter on a switch of some sort. The Carter is known not to have a long life span and this will get you the most for your money....the FM100, I wouldn't worry about....plenty have been running it and I haven't heard a failure, personally. Again, I doubt both pumps will fail at the same time so you will always have one to rely on........just my opinion though.

I think my wording was screwed up once again. I did actually mean to deliver fuel when turned off or failed. Sorry if I further confused things.

Even if one runs 2 pumps in parallel the lines come together at a certain point correct? Assuming 1 pump was stronger then the other wouldn't the same condition exists where the stronger pump would want to pump back up toward the weaker pump or at least creating resistance against it?

For example, there are guys running a A/C Delco pump in parallel with a Carter ...in my diagram the A/C Delco pump would be on the top line where the ball valve is located. It would seem to me that when both pumps are on the Carter would push fuel up up and back toward the GM pump ...creating resistance against it?

Assuming this happens how is that different then my diagram even though the FM100 and Carter would be in series? I was assuming with the Carter off, pressurized fuel from the FM100 would bypass the Carter via the bypass line...and when Carter is on fuel would flow thru Carter and also around it via the bypass line. Assuming fuel is pressurized by the FM100 in the Carter/bypass plumbing would not having a check valve where the ball valve is cause a problem? I'm just trying to determine the best approach vice ending up with 2 pumps that don't do anything except 'hmmmm' :)

I doubt you would backfeed a pump considering the main pump drawing fuel towards the motor.......it would just be a crutch for lack of better words...adding assistance if needed.

The way you have it set up now, if the FM100 were to fail, you would be screwed if the main pump could not pull through it....neither the Carter or the FM100 is designed to be a flow through, but that doesn't mean the main inection pump can't pull through it they failed to keep you from being stranded....just that they weren't designed to. I know the Holleys aren't designed to be pulled through either, but I know a guy who drove on a failed one without a bypass.
Running them in parallel will also keep the pressure around the 7-8 area....which is plenty, imho.

It will somewhat flow through a fm 100 or a pair of them are anyway. You will be severly limited on power and I duno if you will be able to run 65 MPH but you could limp your but down the shoulder or outa traffic. You need to run the pumps in parallel IMO. Likelyhooh of both pumps shoting craps is not very likely. Yes when running in parallel your lines come back together. Think batteries. If you wire a batt positive to negative then what do you do to the voltage? What happens if you wire the negatives together with the positives?

Well I'm frustrated enough with myself for not thinking this out enough that I'm going to say screw it and run the Carter full time ...until a better setup is available or I find patience to redo my plumbing. I'll just close the bypass and it should work fine ...I know at least 4 other people running the Carter solo ....most of them without a bypass :)

I received email from Standadyne this morning. Facts on the FM100.

1) Will not flow fuel on failure

2) Restricts anything downstream to 40 gph

3) Avg life expectancy is 10,000 hours.

I also think it uses 1/4" NPT fittings ...

yup 1/4 NPT. I used 8AN to 1/4 fittings.

40 GPH is why you have to run 2 parallel, they dont pump enough volume to get the job done by themselves I dont think.