3.1EyeCandy

iTrader: (3)

Just curious what my options are here. The car is up in the air getting some ebMiller brake upgrades and I have the 4th gen tank here (with pump). With the 4th gen pump having the built-in regulator, what are people doing about adding a T to the thirdgen fuel lines to function as the return? It seems somewhat redundant to use the vette fuel filter for this purpose....that's 2 fuel regulators. Any guidance? Part numbers?

3.1EyeCandy

iTrader: (3)

This is what I have right now:

3.1EyeCandy

iTrader: (3)

I haven't removed the 3rdgen tank just yet. But am planning on using 1 1/4" fuel line to fill the tank with. Does the metal inlet detach from the 3rdgen tank and simply clamp on to the 1 1/4" line? Or is there something else I need to make it look factory?

five7kid

iTrader: (14)

Did you search? There was a thread about it a month or two ago.

Z28ricer

iTrader: (2)

Are you sure that tank is from an LS1 and not a V6 ?

You need the filler neck to go with the 99 + tank, the thirdgen filler is a much larger tube with a small 5/8 or so pipe inside it.

3.1EyeCandy

iTrader: (3)

Yep - lots of searching. I'm just trying to head off walking into a parts store with a list I'm unable to find if others have found the parts online. I'm wanting to put the tank in while I have the rear-end out of the car...guess I'll just cross that road this weekend and document what I figure out.

I hope the tank is from an LS1 - that's why I bought it. Got it from a local thirdgenner and he said it was from an '01 SS. Any reason I should be questioning that?

cam-

Do you know if the V6 tanks come with a built in regulator?

Z28ricer

iTrader: (2)

Yes, they do, thats why i asked if his was a V6 tank, im going to go compare i've got the senders for both i'll post up what i find in a bit.

3.1EyeCandy

iTrader: (3)

From everything I've read, the LS1 tank has the built-in regulator. You noticing something on this tank I'm not? Hope it's not a v6 tank...

Z28ricer

iTrader: (2)

Got to pull the sending unit to find out which it is, the top they are externally identical, the pressure regulator on the LS1 sending unit is right on the bottom of the sending unit top and you'll notice it quickly once you remove it.

cam-

So where is the regulator positioned on the V6 tank?

Z28ricer

iTrader: (2)

On the fuel rail under the hood, attached to the intake manifold

cam-

Well I guess that explains the fits I was having with my tank on initial start up. I was "told" the tank was from a V8 car and I just assumed all along that the regualtor was there which it wasn't/isn't and that caused me a couple days of concern and now me thinks its a V6 tank. Wish I knew this then but cest la vies

Thanks for the heads up.

As for the fuel lines I mounted a Vette filter in a similar place to the stock TPI filter and routed the return back from there. Its pretty easy. If you have a V8 tank just place the tee in the same area and route back from there.

ghettocruiser

iTrader: (4)

Yup.... Good way to do it!

My solution was to just use the stock 4th gen lines. They fit perfectly until you get to the front subframe area. Then the 4th gen line kicks out towards the middle of the car, then back in.

What I did was cut that kick out, and reconnected the line with a stainless compression fitting. Those fittings if installed correctly will seal and hold plenty of PSI. The line was then secured all along the chassis and into the engine bay. Doing this allowed me to use the stock LS1 quick disconnect line to the rail. Which I later replaced with russell fittings and braided line.

Here is how my lines come out in the bay. There are two, because I have the EVAP system hooked up. But...if you arent using the 4th gen EVAP, you'll only have the one line. You can also see where one of the compression fittings is...if you look into the trans tunnel near the bottom you can barely see it.



And the hook up...


Im thinking about redoing it next time around though. Might go with custom soft lines and do something to get them away from the headers more. We'll see... Definitely works great for now though.

J.

five7kid

iTrader: (14)

If you're using the 4th gen lines from the tank, then you should be able to use the flex lines from the engine, correct? My engine came with the flex lines, but I don't have the 4th gen hard lines from the tank. I do plan on using the 4th gen evap system.

It looks like where you cut the 4th gen hard lines is the same place the stock 3rd gen carb V8 lines turn to go over the tranny tunnel. That may be something I can do to minimize the length of lines I have to replace, and simplify attachments.

cam-

I used the stock LS1 plastic lines fom the tank to some short 12" or so hard line pieces that I bent up that run to the Vette filter and then one single 3/8" custom hard line up to the rail. I bought some stock Buick fuel line assemblies at a swap meet and used the 3/8" pre molded flex with a bit of hard line and swagelok compression fittings to join it all up. Now that i type it it sounds complicated but it was really easy as ****

ghettocruiser

iTrader: (4)

Yeah I can picture what you did cam. Sounds like a good way to go about it!

Honestly, the only reason I used what I used, is because I had a complete donor car sitting right next to my 87. So I figured why not. Stock plastic lines from the tank to the stock fuel filter. Then ran the hard lines up, did the cut/splice and viola.

I could have used a roll of 3/8" line or something even easier I guess. But I wanted to use the stock quick disconnect fittings, and I figured this was the easiest way.

Not sure how Im going to do it this time around though. Ive been toying with the idea of running braided line all the way up. Im also trying to come up with a way of re-routing it so it doesnt have to go between the subframe and the header. Thinking about running it inside the "chassis rail", and having it come up inside the engine bay somehow. Thats on my list of "Things I would change if I could do them over....which I get to do now..." haha.

J.

cam-

Yeah having a donor car is the best route to go if at all possible no doubt about it. So many little doo dads that you can harvest off a donor car that saves a TON of time and cost too.

As for the fuel line routing in the header area great point this was the biggest pita I had to deal with. Normally I would never even consider running a fuel line so close to the exhaust but as you said barring running it literally through the frame there is not a lot of options. The one good thing about these fuel systems is at least its a one way trip for the fuel once its past the filter at the back so its not like the exhaust can heat up the whole tank of gas. My line is routed in an awkward loop around the O2 sensor with about 1.5" minimum clearance and then i wrapped the whole line with "cool tube" heat safe loom. I have checked the fuel line temperatures near the rail in mid summer heat and it stays cool so I dont think I have any worries. It was a complete biatch to bend the hard lines around that header/O2 sensor area though. Once I cross over the header i stay there and route up behind the trans bellhousing and pop out near the oil sensor.

Geez again this sounds even more complicated but it really wasn't. Just very VERY fiddly to get a clean route.

ghettocruiser

iTrader: (4)

I agree... Routing is a pain. My lines get pretty darn close to my headers. But a couple things made me feel ok doing this. 1) the headers are stainless, so I dont think they get as hot as some and 2) like you said, the fuel is zipping past and thats it.

Unlike others, I had tons of clearance with my headers. But its still tight in my opinion. Well see what I can come up with when spring hits and I get everything torn apart. Another Idea I had was to split some 3/4" - 1" tubing down the center. Cut a 1" slot in the "chassis rail", weld the tubing in the slot. Then lay the fuel line and rear brake line in there. Use some stainless and make a nice cover that screws of the new relief. I dont like the idea of cutting into that area, but welding in the tubing should make it just as strong. Plus Im building some massive SFCs from scratch that will help tie that area into the unibody more. Just an idea rattling around...

J.

five7kid

iTrader: (14)

I don't see why you couldn't snake the line through the frame rail. No need to channel it.

ghettocruiser

iTrader: (4)

I guess my thinking was for future work... Once it exits the chassis rail, it will be bending, and snaking it back out for whatever reason would be impossible.

Now if its braided line, then it might be ok. This is why I need to give it some thought. It all depends which route I take. It could be as simple as making an entrance/exit hole, grommet, and snake the line through. But if I want to keep the line steel, Ill need to do something else.

Plus...my channel idea will be protecting the brake line...which in my opinion can cause more issues than the fuel line. Since the fluid just shifts it doesnt really flow through like the fuel does, Im afraid of it cooking... Might not cook...but I dont really want to have to fix it if it does, know what i mean?

J.

StevenK

iTrader: (1)

Wow its like this thread was for me.

I have the stock thirdgen tank with a walbro pump, stock 91 TPI lines up to regulator to motor.

Well, Fuel Pump keeps dieing, randomly, like looses pressure, then eventually 0. Wait a few hours, back to normal. Gay.

So I picked up a matching tank 00 V8, and I've been thinking about how I want to do this.

Unlike you guys, I was not so lucky with my headers...Mine is like 1/8th inch from touching. So I wrapped the hell out of the longtube where it was close, to the point that now the wrap is wedged between the lines and header.

I took the temp guage to the headers after a drive, ~200-400 degrees depending where you hit it. That can't be good. So now I'm thinking about doing the in frame rail braided line, but I can't decide if thats a good idea. Plus, the return line will still be there.....

Which brings up this question (again). Why should I/Should I not run the return line when I swap to the 4th gen tank? I've read, asked questions, but I'm yet to actually read an answer that "clicks" in my stupid head.

cam-

Aside from the 97-98 fuel rail there is no return on newer LS1 rails. The return on stock V8 fbody applications is right where the stock third gen filter mounts ( under the rear driver seat area ) so I fail to see why you want to run a return up through that tight exhaust area for no reason.

Might want to shim under an engine mount to center your headers this will help you gain a little more clearance.

1988RSLS1

I took my EVAP line out and the canister (I need place for stock GTO intake).I used my stock lines and 4th gen stock lines. So form the tank I have 4th gen plastic to 4th gen metal lines, than the stock 3d gen ones, than in under the hood i just cut of tips of my old lines and put on the 4th gen ones and then used stock 4th gen piece to the rails...I have to relocate the filter as well...bending and compression fittings took a lot of time..I checked them, seems like they wont leak, so I hope for the best...

TonyC

iTrader: (1)

I was able to source some 1 1/4" Fuel hose locally, but I'm not sure what to do about the actual metal filler portion where the gas hose goes, suggestions? 3.1, did you get it figured out?

Thanks
Tony

3.1EyeCandy

iTrader: (3)

Yep. I bought the 4th gen piece (fuel filler neck). Works great and wasn't too expensive. I don't recollect where I found the part #, and haven't kept very good records either. I did buy it from gmpartsdirect though.

TonyC

iTrader: (1)

Thanks, if you happen to come across it or if anyone else has it, could you post it up? Did you end up keeping all of the EVAP equipment on the tank?

3.1EyeCandy

iTrader: (3)

If I come across it (not likely) I'll post it up. If you do your research on this forum, it is especially difficult to keep the EVAP equipment working with the 4th gen tank/3rd gen car. Ghettocruiser has put alot of work into it and I don't believe his is working.

However, I left all of the evap stuff on the tank. It just vents to atmosphere though.

ghettocruiser

iTrader: (4)

TonyC I did the same thing for my fuel filler neck. Got a new one from GM Parts direct. You can call the dealer and get the part number. Just ask them for the hose...then say something like "I need to call back to order, can I have the part number to make this easier?". Sometimes they dont like giving out the number for some dumb reason. Anyway...get the number and go through GMPD... Its cheap.

Also...for the evap. Def do some searching. Like 3.1 said, I fought with it for awhile. Basically...you can either have evap work, or have a working fuel level gauge. But not both UNLESS you run the entire 4th gen dash cluster. Then everything hooks up like factory. But using aftermarket, or thirdgen stock gauges...its no dice for both. I wont get into full details here..just do some lookin around via my screen name. You'll come across it.

J.

TonyC

iTrader: (1)

Thanks guys,
Yeah I've done quite a bit of searching but it seems like there are still a bunch of unanswered questions. To help out a bit:

The part number for the upper metal part of the Camaro filler neck assembly is 10409868. Seems the dealerships are saying it's discontinued but GMpartsdirect.com has it for 35 shipped

A few guys on the LS1tech board are venting to atmosphere and they do a similar thing that they put a small breather filter on the large black fitting that sits towards the front of the car (pointing towards 3 O'Clock on the picture in the second post in this thread).

What have you guys done about the white fitting coming out of the tank? In a few other threads they've put breathers on that as well. I saw one Nissan swap that incorrectly labeled it as a vent. Could that be t'd into the breather coming out of the big black fitting so that one breather could be used?

Tony

3.1EyeCandy

iTrader: (3)

I don't have many miles (less than 10) on my swap, but I just left it hanging :-/

TonyC

iTrader: (1)

Well, turns out GMPartsDirect can't get the upper metal part as GM discontinued it ANYONE who didn't use the stock filler neck, any ideas????

ghettocruiser

iTrader: (4)

Yup...junk yard. I thought you just needed the rubber extension piece. You should be able to use the filler neck out of any 4th gen f-body... not sure about the Lt1 cars, but all the LS cars should be the same. Double check... But they are a piece of cake to pull, and should be cheap.

Give these guys a call also...they're pretty good.
http://www.tacreationsusa.com/

J.