Thumper33

So for refreshers, i'm putting a 2000 vette LS1 into a 2000 Jeep Wrangler. I took about a 3 or 4 month break from working on it because I got frustrated with all the time it was taking. Now I'm ready to get at it and get it done.

The question for this post is really - what fitting and pipes/hoses will I need to finish installing my fuel pump.

Now let me explain...

I've talked to aeromotive and they got me a pump that will work. I bought it though Jegs and they sent me two different fuel filters. I'm missing a few fittings and I don't know exactly what, and I'm not sure how exactly to get this done.

First off, lets start at the beginning of the system and move forward. Here is a picture of my jeep pump assembly. I can't use the stock pump because although the tell me it might flow enough, it's pressure regulated too low.



So the way the factory pump works is that it pumps up through the center into the regulator right on top of the tank. The reg returns excess gas back around the sides through the other holes. Better seen here...



So I hollowed out the regulator so that I can at least use the top here as the return line. it should keep the factory pump cup filled with gas like the original system did just using the factory pump. I thought that this would make a good place to suck gas from. Here comes the first design question... would I want to suck gas from the bottom of the "gas cup" to make sure I'm keeping as much air out as possible, or should I suck from high up on the cup since it should always be full anyway? My only concern is that there might be bubbles from the gas returning and splashing on top. However, this would mean that the level that the out of tank pump has to draw from is higher, so less back pressure (which I understand is bad on external pumps).

So my idea is to cut a hole in the top way off to the side to avoid the regulator on top. I can use a bulk head to seal it, and then use two elbows to go to the middle, then down into the cup. I'll have to cut a hole in the top of the cup to get into it, as I don't think there's enough room to just squeeze it in. Kinda like this...



One of my concerns is what material is the hose going to be made of that's going to go in here. I don't want it to be a soft rubber hose because it might collapse under the suction, and it might get cut from the metal it has to rest on. So next question is... How do I do the bulkhead and 90 degree bends, and what type hose do I use?

So once we're out of the bulkhead, I need to mount the pump as close to the bulkhead as I can to minimize it's work. I'll have to figure out where, but I'm thinking I can make a bracket right on top. Is there any advantage do you think of me mounting it actually lower than the top of the tank... so once it starts a sypon, it'll be at lower pressure there?

So here's a picture of the pump...



The pump is pictured flowing left to right. So they gave me an AN adapter fitting for the input. It's a size AN 8 fitting. I don't know what to do with the other side though. Compression fitting? it obviously needs to go to the filter.

So the next question is that they gave me two different filters. One is a straight through, and the other has a return. The fuel rail I have doesn't have a return on it, so I'm going to assume that I need to use the fuel filter with the built in return on it. They did give me AN fittings to mate this stuff up, but it didn't have a size on the AN side so I don't know what size fittings to get, or if I need an adapter or what. What do I measure to know what size AN it is?

Here are the two filters they gave me...



They gave me one fitting for the red filter as you can see, but not one for the other side. Not sure why. I have compression fittings for the return style filter to make them AN fittings though, just not sure what size.

So I guess I can run the return filter and run the return line back through the regulator as I had planned. that should be easy enough.

From the filter forward, what type of line should I use for that?

Okay, that was a lot to read I know, and some of it was basically just talking myself through what the heck I've got and what I'm doing. Can anyone help fill in the gaps here?

Thanks! And if you got this far THANKS A BUNCH FOR HELPING!

strokedls1

iTrader: (1)

You can get an bulk head pieces to run line into the tank and seal everything. The question is are you trying to reuse the stock fuel feed line? Depending on the power goal for the future would make the decission of lines easier. On my friends car we did a 8 an feed and 6 an return. If you are running a return system at the rails then I would say a 6 an feed and return would be plenty for a stocker motor all the way up to 500 rwhp. Run the lines into one rail with a line connecting the rails then out the other rail into a regulator. From there is would return back to the tank. Preferably I would mount the return toward the top of the tank. The pump needs to be mounted as low as possible in the tank. Measure twice mount it once. Take into account a filter for the tip of the intank pump when setting install height. I just cut four holes into the side of the tank and use plastic ties to secure the pump in place. The line out of the pump is just rubber fuel line. Any auto part store sells it. Some go through the trouble of doing braided line, but I think it is over kill. It is pumping fuel so it will never collapse in. It can blow out from the pressure. You can use metal band clamps to secure the line to the pump and to your an fitting.

A good idea someone gave me is to shop for an fitting at air plane supply places. Usually 25% cheaper than automotive stores like summit racing. I hope that shed some light. Good luck with the project.

Thumper33

Thanks for the reply, I think there are some misunderstandings (either on my part or yours).

I wasn't intending to use my pump as an in tank pump, mainly because I couldn't figure out how to get it to work with the stock pickup system so it's always pulling fuel from the very bottom of the tank. I'm afriad that if I get on an inclide of any kind on a 1/4 tank of gas then it'll all run away from the pickup tube and the engine will die. So because of that, I thought I'd use the stock pump to fill that coffee can looking thing, which should always be full of fuel becuse the return dumps into it, and just suck fuel from there.

I had planned to mount the fuel pump outside the tank because of that issue. The reason I had mentioned the line collapsing is that I'll be sucking fuel from the tank, not pushing it out like an intank pump would be.

Yes, the motor is stock, and I really plan to keep it at least mostly that way. definitely not over 500 hp.

I guess I can just use all rubber lines cause that would be easy. I'm not using the stock line to the front because it wasn't big enough anyway. Also, my system only has one fitting on the fuel rail, my return is in the fuel filter.

bczee

iTrader: (12)

Have you looked at the Tanks Inc intank setup. maybe that will give you some ideas as an alternative or using it as alternative to what you are trying to do..

The Aeromotive filter is nice but might be overkill.. but you have it, you will need a regulator to go with it.. and a return line from the regulator to the tank.

I think the other one is the 99' Vette Filter/Regulator.. it will also work, I am using one in my swap. When it comes time to replace the filter or it fails, you can get it almost everywhere. (as long as it is in stock it or can order it quick enough).

If the engine is Stock.. Almost anything will work out as long as it has the required Pressure (58psi), volume and doesn't starve out.

I would not complicated any install if I didn't have too and it sound like you may be doing that with your plans. Keep it simple (the KISS rule)..thats my 2 cents.

good luck, keep us posted..

kossuth

iTrader: (12)

Here is what I would do if I was you. Stay with a 3/8' line. That would be 6AN. As long as the stock fuel pump sender is big enough to stick a 3/8' line into it I would use that. Then go with an external pump with -6 braided line and then go to the Corvette fuel pressure regulator/filter then to the fuel rail. Plumb the return back into the tank the same as always. I'm surprised that you don't have a factory 3/8" fuel line on that thing. That is pretty standard, unless they change things up for the 4 cylinder jeeps and that is what you have. If the 4.0 jeeps have 3/8 lines then it's totally resonable to just go with a 4.0 tank and lines and such all the way to the fuel filter if a jeep has one (some Chrysler vehicles don't) and go with your own lines from there. From there you can modify the regulator and install a different pump if needed. It seems that the majority of in tank pumps made by Chrysler are made by Walbro and are identical if I can remember to the intank pumps GM has. I'm not a fan of external pumps because they aren't quite as reliable as their external mounted counterparts, (but alot less of a PITA to change out when they go bad). If the factory lines and so on are less than 3/8 then it might be worth your while to get a fuel cell with the proper baffling and such to make your rig dead nuts reliable on the trail. I truely think that -8 stuff is way overkill for your application. I'd go with a -6 feeder, and a -6 return to just keep it simple.

BTW, in case you were still wondering about what the labelling of like -3, -4, -5, -6, -8, and so on and so forth means it is actually just the military's way (the AN/JIC fittings have their roots in aircraft and marine hydralic systems) of saying if you need a -4 hydralic line that the line is 1/4 of an inch. Basically that number is a faction of a 1/16th of an inch. So a -6 line is 6/16 or 3/8" and a -8 line is 8/16 or 1/2". Make sense???

98TJ

The 4.0L uses 5/16 fuel line to the fuel rail. It is a returnless system like the newer LSx's. Since you already gutted the stock regulator, just use the stock line as the feed into the Vette filter/regulator. You will have to convert the 5/16" to 3/8" somehow, but shouldn't be a problem with adapters. Then use a bulkhead fitting through the sending unit lid for the 5/16" return line from the Vette F/R. Finally, run 3/8" hard line from the Vette F/R up to the LS1 fuel rail.

mullenh

iTrader: (1)

to solve the issue my car we used a rail mounted fuel pump $100, and a 1999 corvette fuel filter with a built in regulator and return line $60