Fuel Transfer Pump (lift pump) upgrade

[monoblock]

I am trying to be logical about this first step in upgrades so have avoided putting this post in the "make it go faster" section. Really I don't want more speed-I just want it to go more reliably and more the way Clessie Cummins (rather than the Dodge Bros. accountants) would have wanted.

There are many recommendations for a modest upgrade to the OEM Delphi diaphragm (fuel lift)pump. I mean a mechanical or electric pump that will support other upgrades that may eventually produce roughly 20-30% more power/torque.It should also improve reliability,reduce leaks .It would give a consistent pressure of 12+ psi? I have read so much my head is spinning with all the alternatives. Can anyone rank the alternatives by manufacturer & part number for reliability/effectiveness? My muddled impression from all the opinions is that the Cummins(not Delphi/Dodge pump) is the smartest choice -but which one and what pressure?


Some of the candidates are:
The Walbro GSL392, aka 255LPH. The similar Holley and generics of the same design(made in China?)
This is a useful link because it graphs the performance of the Walbro pump:
http://www.ebay.com/itm/230906992478?ss ... 1423.l2649

Cummins Fuel Transfer Pump ? Cummins Part Number:3936320 . Interchange #: 4944714,4988751 $65 on EBay

Hungry Diesel's tweaked pump (what part number/what tweaks?) $265 +core

The HFP701 or HFP 700 piston pumps-big difference in price between these two part numbers.

Then there are little mods with shims,gaskets.

It would be brilliant if someone could boil this down to just a list of 1 pump and a shim !

[RCCUMMINS89]

The Hungry Diesel (me) has a factory 2nd gen style pump #4988747, genuine cummins lift pump and all cummins parts needed to put it on.

The pump has a different internal regulator spring in order to meet the psi output that our pumps require.

This pump has a larger piston than the Cummins low pressure lift pump, and has a larger piston and higher psi than the delphi lift pump.

If you want to stay mechanical, this is the best route.

[rockmike]

http://www.thehungrydiesel.com/Lift_Pump.html

Good guy,lots of knowledge,the correct pump! call him up.

[rockmike]

Ha Ha ya beat me to it.

[oldestof11]

I loved my Walbro. Make sure you regulate it. I used a Mallory 4307M.

[RCCUMMINS89]

Hungry Diesel's tweaked pump (what part number/what tweaks?) $265 +core

Core? no core charge.... all of our parts are new.

[cmann250]

I have a Cummins low pressure piston pump and I'm happy with it. I suspect I'm beyond the 30% additional power, so it should meet your needs just fine.
I'm a wheeler dealer, so I got a new Cummins pump for less than they list for. However, if I were to do it again, I'd buy the pump RCCUMMINS makes. His prices are extremely competitive and I've seen alot of good reviews of his product.

[PToombs]

It's getting really hard, and really expensive, to find the correct cummins low pressure LP anymore. Most of what is sold claiming to be the correct one is no good or wrong. If I was going to buy one today I would buy one from Eric. (hungry diesel) I prefer to stay with a mechanical pump, less electric headaches.

[monoblock]

I read several tech articles by Tork Technology . One of the well argued cases he makes is for a much larger diameter inlet pipe from the tank to the transfer pump ,remove the 'necks' and 90 degree fittings where possible.Perhaps that should be part of the upgrade?
http://forum.mopar1973man.com/threads/2 ... 12V-owners

[RCCUMMINS89]

Yep... anything to reduce fuel system restriction.

I run a 3/8" supply and 5/16" return..but everything else stock. I should upgrade the sump tube (inside the tank). Larger banjo bolts, and even an upgrade hard lines (lift pump to filter and filter to injection pump) as well as larger filter all increase the volume of flow that a lift pump can move as well as makes it easier for it do it's job.

[DodgeFreak]

I'm running a hplp with mallory regulator. I went this route because I was/am debating pee pumping one of my engines.

[revemup15]

Since eric has sumed up all the basics not much good info left to say besides, I have a piston pump from eric and its great... cheaper than dap for there junk piston pump kit and its a genuine cummins pump which has a bigger piston (for more volume) than the leading competion expensive junk kits out there. Give eric a call you wont regret it

[monoblock]

Yep... anything to reduce fuel system restriction.

I run a 3/8" supply and 5/16" return..but everything else stock. I should upgrade the sump tube (inside the tank). Larger banjo bolts, and even an upgrade hard lines (lift pump to filter and filter to injection pump) as well as larger filter all increase the volume of flow that a lift pump can move as well as makes it easier for it do it's job.

Thanks for this practical confirmation . It seems Tork Technology had a good point in the articles linked above.

[monoblock]

I found a Big bore upgrade kit for latter models but it gives some ideas for our 1st Gens?
http://articles.mopar1973man.com/genera ... g-line-kit
Related, I found an interesting article on improved fuel filtration using a "CAT" filter.It is adaptable(?) to our trucks perhaps:
http://www.cumminscatfuelfilter.com/

[DodgeFreak]

You can install it. You need the filter head\s. I've got two filter heads and a filter and water seperator to install on mine. I'm still debating to put mine inbetween the pump and the tank or inbetween the pump and injection pump.