Jump to content

Which Lift pump???


Recommended Posts

Hey guys, Now I know iv'e been over this particular topic before but iv'e come to view some new info regarding lift pumps well new to me anyway lol. So I was vewing some threads on here and came across the Assassin lift pump, and read that these pumps actually increase pressure with RPM's which of course I really liked that, and the fact that there a mechanical pump. Also during my discovery i read that in order to install this pump you have to replace the draw straw. Is this something that absolutly has to be done with this style of pump? My original choice was a Raptor 100 but also viewing some threads on here I discovered that the new owners of AirDog F..... them up so am not sure I want to go that route. And then I found the below from Homestead, and really liked this idea because of the costs. My truck is bone stock, and I dont really plan on towing anything maybe a car, or when I decide to relocate and load all my crap on a trailer and go other than that 95% of the time my truck is empty. Dont really plan on doing any mods to it other than a 4" or 5" exaust although +50hp injectors are appealing to me more, and more lol. Allready got my BHAF installed!!:thumb1: Just trying to figure which one would be best for the cheapest price before my stock LP craps out on me. Bare with me gents! Below is Homesteads post! My "kit" is parts and pieces from Vulcan as well as stuff sourced from a local parts store. The tank module is factory stock, no draw straw at all. The connection to the tank is factory as well. My "big line" actually starts just before the tank itself on the frame rail.The Carter pump is mounted directly below the drivers seat on the outside of the frame rail and feeds the factory filter canister/heater assembly. From there is is "big line" directly into the VP. The pump wiring was extended down to the frame mounted pump using a Vulcan harness but they are simple enough to make.Everything is Push Loc type rubber hose, braided or anything is not needed. Push Loc is cheap and available just about anywhere and way less hassle that braided. I had braided at first, waste of money for this application.I have my stock OEM Carter set up this way, been that way for over 150,000 miles on the same pump. Pressures are 15/16 psi at idle and WOT won't go under 11 psi. Big line from the front of the tank to the VP with only the factory filter canister in the middle.Jeff

Link to comment
Share on other sites

kinda in same boat as you. called eric at vulcan yesterday (really nice guy and he knows his stuff) he said that the raptor 100 is good for up to 500hp so thats plenty for me but he also said that for some reason they have had less problems with the ad100 , so i dont know what to do. good luck and post up what you decide

Link to comment
Share on other sites

The Raptor and the AD100 use the same motors. I believe the biggest contributing factors that lead to the AD100 lasting longer are that it is mounted on the frame rail rather than the engine. No heat or vibration to deal with, and the pump is pushing fluid rather than pulling. The AD100 also draws fuel through the f/w separator before going through the pump so any debris is caught in the filter before going through the pump. The Raptor only has a small screen in the inlet of the pump.

Posted Image

A fella I know was going to trash his AD100 because the motor was burned up, so I mated my Raptor motor to the AD100 frame with 1/2" fuel line from top of tank to OEM canister to VP. 18 psi at idle and 15-16 psi under heavy engine loads.

JR

Link to comment
Share on other sites

  • Administrator

Don't know you would think so though. But don't know if I want to take that chance. I do like the adjustable fuel pressure screw though.

Sent from my iPhone using Tapatalk

No you won't. There is more issues with the adjustable pressure regulator than the old school check ball and spring.

Link to comment
Share on other sites

Oh ok thanks for the info MoparMan. That was the main reason I liked that one. That and it looked like an easy install. Regarding the Assassin do u have to replace the drawstraw? Really don't want to drop that tank since I'll be the only one doing this install. Any thoughts on another pump that would be reliable, cheap, and an easy install? Sent from my iPhone using Tapatalk

Link to comment
Share on other sites

  • Administrator

Sorry to say for optimal performance you going to replace the Drawstraw like it or not. If you keep the factory sender you'll notice much wider pressure swings than if you do it right and change all plumbing from tank to VP44 to 1/2" lines. As for the pump regulator I've got the old school spring and check ball. The only thing I got to do once in awhile is pull it out and set it back up. The ball tends to work its way into the spring coils. As for the adjustable regulator the common problem there is that pressure falls a bit people adjust up again. Then next morning its too high now adjust down. Up.. Down.. Up... Down... The cycle continues. The problem is the mess of springs and sliding plunger that is suppose to control the pressure but it only takes a small bit of debris to hang it up. Adjustable http://forum.mopar1973man.com/attachment.php?attachmentid=3372&d=1325366951 AirDog Check ball and Spring. post-2-138698211773_thumb.jpg

Link to comment
Share on other sites

Ok. As far as the original pump you think I'd be ok by doing what Homestead did moving it to the frame, and running 1/2 line from the tank to the vp44, and maybe a 2 micron filter between the tank and LP? I noticed he said it only got 11 psi at WOT kind low to me. I know anything above 10 is good. What do you think? Sent from my iPhone using Tapatalk

Link to comment
Share on other sites

  • Administrator

Ok. As far as the original pump you think I'd be ok by doing what Homestead did moving it to the frame, and running 1/2 line from the tank to the vp44, and maybe a 2 micron filter between the tank and LP? I noticed he said it only got 11 psi at WOT kind low to me. I know anything above 10 is good. What do you think? Sent from my iPhone using Tapatalk

14-20 is optimal. The over flow valve is open and the cooling and lubing of the VP44 is optimal. 10-14 is marginal. This is the period of time that the overflow valve is starting to close. <=10 is damaging. By the time the pressure falls to 10 PSI the overflow valve is completely close and zero return fuel is given so now there is no extra cooling for the PSG and no extra lubrication for the part internal parts. http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/25-fuel-system/88-bosch-vp44-injection-pump-overflow-valve
Link to comment
Share on other sites

The Carter pumps are non adjustable. I have mine still on the side of the block and when I plumbed my AD100 in I teed the Carter in with a series of valves so in case of a failure I can valve the Carter in, plug it back in to vehicle side harness and bleed the fuel system out to get the truck running and get on home. I have tried this a few times in the comfort of my garage just to make sure it will work seamlessly and running that Carter I have seen it drop below 11 psi. I believe new they may be able to hold 10 to 12 but I have also seen one drop as low as 6 to 8 psi under heavy load. I may have missed if you posted your known fuel pressures? But whatever your getting now you can pretty well expect after the relocation to the frame. The difference maybe being the pressure won't drop off quite as fast due to the larger lines but it will not be able to maintain that pressure under heavy engine demands for extended period of time. JR

Link to comment
Share on other sites

  • Administrator

So 11 is ok but I would like to get it as high as possible so if I use Homestead's set up do you have any tips on how I could get it any higher other than getting a different type of pump? Sent from my iPhone using Tapatalk

11 PSI is like saying Cummins engine needs a minimum of 10 PSI of oil pressure at idle and 30 PSI at 2K RPM's and you've got 11 PSI and 31 PSI. How long would you expect that engine to last? Same goes for the VP44 pump how long do you expect it to last? Also consider the accurancy of the gauge. What if the gauge is +/- 1 PSI accurate. So that could mean at worst it 10 PSI or 12 PSI. Why hang right at the breaking limits of specs when you can have some breathing room.
Link to comment
Share on other sites

You can always get the mechanical pump and just install a fuel sump on the tank. This way you dont have to drop the tank to install it. Mopartechnician has some really good info on it. Otherwise if you want to stay electric than I would look at a FASS 95. Fass is still a good brand for electric pumps.

Link to comment
Share on other sites

Ive had good luck with raptors/airdogs. Only have had two warrentied in the 2 dozen plus i have installed. The one that i have warrantied, i had the pumps in 3 days no questions asked. I personally run a airdog 2 165 on my truck. The problems pureflow was having is some idiot thought they needed to change the aeal design between the pump and motor. Well fuel ended up getting in the motors and shortening them out. So far so good on the updated design. The pumps i warrantied were installed 2 years ago or so and i have done many in the last two years with no problems. The best thing to do for any pump is to have a good fuel preasure gauge (i have an electronic and mechanical fp gauge). I cant remember the name of the company, maybe velocity, but they are suppose to have some nice pumps. But they are expensive.

- - - Updated - - -

Likeoldfords, what's your opinion on the FASS DDRP?

Sent from my iPhone using Tapatalk

Stay away from anything mounted on the engine. Heat/vibration kills pumps. Plus its easier on he pump to push fuel instead of pull fuel
Link to comment
Share on other sites

×
×
  • Create New...