Ka24de fuel question

[SubwayGUY4]

Hi just recently finished my swap and I am now realizing that the way it gets fuel is pretty....how can I say it unsteady?

 

I was just wondering what other people had done via fuel pump. I have a inline pump sitting next to the gas tank. So I guess my question is...Is the way the stock gas tank setup feed fuel into the pump fast enough? or did everyone weld in a intank pump? or something idk shoot me ideas thanks

 

2 door 510

[Creepy Cruiser]

I ran 2 new 5/16" hard lines front to back. I used a sender ring from a hardbody tank. I run a cut down s13 sending unit in the tank, with an s14 pump. I built and welded in a EFI baffle to keep everything smooth. I have no starvation issues at all, all the way to an empty tank.

 

Getting ready to weld in the ring. s13 sender mount in the background.

 

All painted up

 

EFI baffle tacked and ready to finish weld, and then weld it in the tank

[dennis]

Some have done it the way creepy cruiser has done it and some have went with a two pump surge tank solution. Basically you run a fuel pump into another tank and a overflow line back into the original 510 tank. Then from the surge tank you run a line to another pump and on to your fuel rail. On my past 510 I ran a 300zx in tank fuel pump kind of like creepy cruiser but without baffles because the surge tank has too many points of failure in my opinion. My current project will be running a 300zx pump with baffles.

 

Ease of fabrication the surge tank is much easier to do.

[dennis]

Here you go, after a quick search on google this is what I have found on surge tanks.

 

http://www.sr510.com/fuel.php

[philcas1987]

I've done inline pumps on non turbo ka's. They do just fine. On a turbo motor. The lines on the tank aren't enough. Surge tank and 2 pumps or intank with baffle is the way to go. Period. With the tank almost empty. On a tight right hander you can hear the inline pump squeal.

[SubwayGUY4]

That makes sense. Sadly I completely forgot about the concept of a surge tank. Thank you everyone

[Creepy Cruiser]

I've seen some great surge take setups also.

[SubwayGUY4]

hmm well also I was wondering...since your supposed to run a lower pressure to a high pressure......would running a 190lph pump to a 255 lph be a bad idea?

[dennis]

hmm well also I was wondering...since your supposed to run a lower pressure to a high pressure......would running a 190lph pump to a 255 lph be a bad idea?

 

I think it would be overkill and your surge tank would be overflowing back into the stock tank most of the time. Remember that 190lph is almost 50 gallons per hour. People run larger volume pumps so the pressure can increase. You do not need to worry about high pressures in your surge tank.

[dennis]

I've seen some great surge take setups also.

 

I agree, but they are also not without a significant cost increase over a setup similar to yours. Also the more complex the setup the better the chance for failure.

[Creepy Cruiser]

I agree, but they are also not without a significant cost increase over a setup similar to yours. Also the more complex the setup the better the chance for failure.

 

Yep, that's why I love mine and went the OEM style in tank route, simple, cheap, and it works great. I wanted the pump to be really quiet also, and having in the tank helps a lot. Some people are really afraid to weld on a fuel tank (and that's very understandable, because it can kill you if done wrong, lol), but if you super super scrub it clean inside and rinse it many many times before you start, it's perfectly safe.

[SubwayGUY4]

I think it would be overkill and your surge tank would be overflowing back into the stock tank most of the time. Remember that 190lph is almost 50 gallons per hour. People run larger volume pumps so the pressure can increase. You do not need to worry about high pressures in your surge tank.

 

 

Yeah that is true. but I have an extra one lying around and figured hey I could put it to use. I also saw that it is usually less than or at least equal to the pump to the rail. Also I'm not sure if it makes a difference but the surge tank I started making is about 3/4 a gallon...

[dvaet]

i have a 71 with a KA24DE and i was wondering if any one hase any pics of thier fuel set up or a drawing of how it should be ran. i wanted to use the factory tank with an external in-line pump. i dont plan on going turbo.

[Guest DatsuNoob]

Check my build thread I got pics of mine. Not sure if its text book correct or not. I just went with the common sense approach of keeping everything gravity fed. I used 3/8" lines to avoid any restriction that may have occurred from any slight kinking when I bent the line. I found a nice link on a DIY surge tank, lemme see if I can dig it up. I know you're supposed to use a high vol, low pressure pump to draw from the fuel tank to the surge tank, then your reg inline pump in front of that. This one looked like a steel co2 bottle for a cheap paintball gun, with the nipple end cut off and a mounting plate welded on in place. Very ratsun

[compression]

i have a 71 with a KA24DE and i was wondering if any one hase any pics of thier fuel set up or a drawing of how it should be ran. i wanted to use the factory tank with an external in-line pump. i dont plan on going turbo.

 

I have seen on 510 tanks that there are two nipples on the tank, one 1/4" which is the main feed line, and another small-ass one, that was probably a return line for some carb setup Datsun was maybe going to use.

I have had good luck running an external Walbro 255 that gets its fuel from the OEM tank fuel outlet, the larger of the two nipples. However, for the fuel return, that second nipple on the tank, the small one, is way too small. So I welded a return nipple on to the fuel filler neck. This setup works great.

If your return line is too small or restrictive, the regulator wont be able to keep the pressure down where it should be and you will be running rich.

 

As for fuel surge tanks, I just happen to know a company that makes a super kick-ass surge tank that has an internal Walbro (or Bosch if you prefer) pump.

They should have them on the market in a few weeks. (shameless promotion, sorry)

http://www.radiumauto.com/universal-efi.php

[Creepy Cruiser]

Aaron, those displays are like a work of art. I want one just to put on the mantel over my fireplace, lol.

[HRH]

On welding the fuel tanks, a good idea is to fill it with dry ice, which will displace any gasoline vapors. Or fill it with water. It doesn't take much leftover vapors to start a really good explosion.