L body fuel system upgrade

[Skibbe]

Anyone have some ideas on mounting a fuel cell in an L body?

The time has come to retire the Walbro in-tank and stock lines/rail. I've got a few parts on the shelf already, like a S60 pump and -6 feed that I'll probably be using. I'll upgrade the rail, and then swap from a rail mounted AFPR to an Aeromotive AFPR also, as I can run AN fittings and braded line on everything.

So, I'm trying to decide what to do for a fuel tank. I'm not ready to go race only, so I don't want to go with a small 3gal cell up front. It would be convenient to drop something in the spare tire well, but I don't think it would pass tech without some sort of vented enclosure seperating the hatch area from the driver. I could cut out the spare tire well, and sheet over it, and then mount a cell underneath that area.

I also have a new stock tank on hand, but don't know if putting a sump on it will end up being too low. The S60 pump came out of another charger that just had the pump mounted externally, and then the inlet plumbed to a piece of rubber tubing laying on the bottom of the tank. Pumps are designed to push, not pull, so that is not something I want to duplicate.

[BadAssPerformance]

You can put it in the spare tire well if you have a firewall over it like I got :thumb:

EDIT: 5 gallon...

http://www.badassperformance.com/mrides/z/04_specs/cell.jpg

[cordes]

I know that AM welded a piece to the tank on their talon which allowed them to run everything off of the stock tank. that seems like the way to go.

[Clay]

what do you run for a firewall JT?

[contraption22]

Doesn't it it have a negative impact on traction to move the fuel tank from in front of the rear axle to behind it?

[Skibbe]

Doesn't it it have a negative impact on traction to move the fuel tank from in front of the rear axle to behind it?

Yeah, which would be one argument for modifying the stock tank.

In JT's case though, his car is a pig no matter where that weight is... and 5 gallons at least weighs less than the 12.5(?) gal stock tank.

Is anyone running a S60 style pump on the stock tank? Without having a two pump set-up?

[BadAssPerformance]

what do you run for a firewall JT?

.030 aluminum or whatever the rules say... I'll find a pic.

[contraption22]

Is anyone running a S60 style pump on the stock tank? Without having a two pump set-up?


Im running a S60 pump with a carb'd tank. Works pretty good... as long as I have more than 1/4 tank of gas.

[Skibbe]

Im running a S60 pump with a carb'd tank. Works pretty good... as long as I have more than 1/4 tank of gas.

How is it set up to draw fuel from the tank? I assume its all downhill from the tank to the pump?

[contraption22]

How is it set up to draw fuel from the tank? I assume its all downhill from the tank to the pump?

Nope,, actually the pump is above the tank. Its not an ideal situation, but it hasn't become a problem yet. I really have been meaning to swap in a TBI tank and turbo pump.

[Skibbe]

Maybe I'm worried about it too much. That's the same way this S60 pump was mounted when I pulled it.

[WickedShelby88]

I kinda like the idea of the carbed pump with an external, but I suppose it would help if one could get the pump mounted in a lower position to try to get the siphoning effect. There are some really good external pumps out there that don't cost an arm and a leg. My friend found that when he was modding anything on his 67 Nova that if you wanted to reuse what you had it always ended up costing more to do it that way then starting from scratch. That may no apply here, but just a thought.

[Skibbe]

Ok, I'm going to order a weld-in sump from Competition Engineering through Summit. I already have a new L-body tank on hand, so now is the time to weld something to it.

http://static.summitracing.com/global/images/prod/large/cee-4041_w.jpg

Looks like I have a choice of 1/2" NPT and 3/8" NPT for the bungs, and will probably just go with the 1/2". -8 feed and -6 return should give plenty of fuel for my set-up.

[mock_glh]

Is anyone running a S60 style pump on the stock tank? Without having a two pump set-up?

I have one in my Omni. I had to split the pickup assembly into two sections so I could get the pump through the hole. I put flare couplers on the tubes and reconnect them after the pump is inside. Been using it for about 10 years, never had a problem.:)

[contraption22]

Ok, I'm going to order a weld-in sump from Competition Engineering through Summit. I already have a new L-body tank on hand, so now is the time to weld something to it.

http://static.summitracing.com/global/images/prod/large/cee-4041_w.jpg

Looks like I have a choice of 1/2" NPT and 3/8" NPT for the bungs, and will probably just go with the 1/2". -8 feed and -6 return should give plenty of fuel for my set-up.

A little tip... instead of cutting out the whole square or rectangle to put the sump in, mark the area and use a hole saw to cut a bunch of 1" holes in the area covered by the sump. It acts like a cheap baffle. Also be careful of the placement of the sump, as the rear axle beam is pretty close to the rear of the tank.

[BadAssPerformance]

Ok, I'm going to order a weld-in sump from Competition Engineering through Summit. I already have a new L-body tank on hand, so now is the time to weld something to it.

http://static.summitracing.com/global/images/prod/large/cee-4041_w.jpg

Looks like I have a choice of 1/2" NPT and 3/8" NPT for the bungs, and will probably just go with the 1/2". -8 feed and -6 return should give plenty of fuel for my set-up.

Nice sump... let me know when you need it welded in.

[Skibbe]

Well, the sump was cheap compared to the $300 of braided line and fittings I ordered to go with it.

Picked up a -8 inline Fuel Filter too. FWDperf is currently out of the fuel rails, but it will take me a little while to get everything else together first anyway.

[Skibbe]

Ok, two years later...

Was playing with the sump today. I can get the fittings to clear the rear axle without any issues. Definitely not going to be able to get the pump lower or level with the sump very easily. Thinking about putting a bracket where the current external pump is (1986 two pump set-up currently...)

http://cgwrr.com/Mopar/86SCblue_files/sumptestfit.jpg

http://cgwrr.com/Mopar/86SCblue_files/sumptestfit2.jpg

Anyone think this will cause issues, either with pump priming on start up, or cavitation later? Does it defeat the purpose of the sump?

[cordes]

How low does that sump sit when the car is on the ground? Perhaps it's just the angle, but I would be worried about something ripping off the lines if I went over it. Obviously that could be avoided wit proper routing I suppose.

[Skibbe]

About 2" lower than a stock tank. ;-)

[BadAssPerformance]

That's a tad low... and maybe would be better further back?

I dont think the pump has to be as low as the sump but even with the middle of the tank should be ok? Mounted close to the pickup would be key so if it does suck air, it would suck less.

[Skibbe]

That's a tad low... and maybe would be better further back?

I dont think the pump has to be as low as the sump but even with the middle of the tank should be ok? Mounted close to the pickup would be key so if it does suck air, it would suck less.

To move it farther back, I could change to one of these:

http://static.summitracing.com/global/images/prod/large/ear-982288erl_w.jpg

But that's a pretty sharp 90...

Or get another bung to weld into the side of the sump for the feed?

[Skibbe]

Ok, took a step back since I wasn't happy with any of the fuel pump mounting options with the sump. So, I'll get the -8 feed and -6 return lines run into the stock hanger and run a single Walbro 255 intank pump for the time being. Got a couple bulkhead fittings installed tonight while I'm waiting for the pump and fuel rail to show up.

http://cgwrr.com/Mopar/86SCblue_files/bulkheadfuelfittings1_800.jpg

http://cgwrr.com/Mopar/86SCblue_files/bulkheadfuelfittings3_800.jpg

I'll probably braze/solder brass plugs into the stock nipples to seal them off flush with the cap. For the intank side of the -8 bulkhead, I'm figuring on using the -8 nipple hose end shown and run rubber fuel line from the pump to this nipple. This way with the bulkhead fittings all the lines on the car side can remain when I get to the point of needing more fuel and can do a dual walbro set-up, or single larger submersible.

And Cordes won't have to worry about me smashing up the sump on a speed bump!

[cordes]

I feel better already! ;)

How much power are you looking to produce? Needing more than a Walbro 255 is some serious action. :thumb:

[BadAssPerformance]

That will work :clap:

[Force Fed Mopar]

I feel better already! ;)

How much power are you looking to produce? Needing more than a Walbro 255 is some serious action. :thumb:

That was my question exactly :)

[BadAssPerformance]

He has an identical turbo to what is on my car :D

[Skibbe]

That will work :clap:

Getting expensive though... damn Unibit for drilling the holes was $34!

[BadAssPerformance]

Dont you work in Arlington Hts? HARBOR FREIGHT!

[Skibbe]

Dont you work in Arlington Hts? HARBOR FREIGHT!

Next town over! Forgot to try there on the way home, was too busy trying to find a roll over valve... Oh well, this one should last through more than one project at least.

[BadAssPerformance]

Rollover valve? :confused2: crap....

By unibit you mean step drills, right? I think the set of 3 I got was $10 ;) ...well, if you count the other $100 worth of crap I got on the same trip, maybe not! Hard to get out of that place cheaply :o

[Skibbe]

Rollover valve? :confused2: crap....

By unibit you mean step drills, right? I think the set of 3 I got was $10 ;) ...well, if you count the other $100 worth of crap I got on the same trip, maybe not! Hard to get out of that place cheaply :o

That crappy plastic thing on top of the gastank that hooks into a vacuum line that's supposed to go to the charcoal canister? plastic was brittle and the nipple broke off while I was trying to extract it from the old tank.

And yeah, those step bits that work oh so nice for sheet metal.

[BadAssPerformance]

I hate 20yo brittle plastic :(

[iTurbo]

Looks great!

I sorta did the same thing on my Spirit R/T. I cut and drilled out the old tubes for supply and return and replaced with 3/8" steel tube from Summit brazed in and used AN-to-tube adapters to hook up the ss AN hose. Using a Walbro 255 ltr/hr in-tank pump as well.

http://www.turbosedan.com/spirit/DSC02790.JPG

[Chris W]

Ugh. Ordered fuel rail and pump from TU.com last Tuesday and still don't have them. Ordered from Summit twice, once Sunday and got it Tuesday, and once Wednesday morning and got shipment today! I realize TU doesn't ship quite as much as Summit, but seriously...

Hi Mike,

Your parts are are already enroute. We upgraded the shipping to get them to you sooner. Our fab shop was finishing up the rails when your ordered. We appreciate your patience.

Chris-TU

[Skibbe]

It's OK Chris, and thanks for the upgrade on the shipping. You're still about 2 years ahead of FWDP! :eek:

[Skibbe]

Got the fuel rail and pump today. Cleaned the flash out of the injector holes on the rail and got it bolted in place... then went to screw in the 3/8" NPT to -8 AN fittings to the ends... TOO BIG.

Doh.

I think the next size down is 1/4" NPT, but that seems damn small, and strange since the fittings TU lists online are 3/8" to -6... I was expecting a -6 (3/8") rail and knew the -8 feed would be larger than the internal dia of the rail, but didn't think it was choked down to 1/4"...

Oh well, Summit should get the fittings to me by Friday so I can at least get it running for the car show this weekend. Then maybe it's time to do my own -8 rail from Ross Machine extrusions.

[cordes]

Got the fuel rail and pump today. Cleaned the flash out of the injector holes on the rail and got it bolted in place... then went to screw in the 3/8" NPT to -8 AN fittings to the ends... TOO BIG.

Doh.

I think the next size down is 1/4" NPT, but that seems damn small, and strange since the fittings TU lists online are 3/8" to -6... I was expecting a -6 (3/8") rail and knew the -8 feed would be larger than the internal dia of the rail, but didn't think it was choked down to 1/4"...

Oh well, Summit should get the fittings to me by Friday so I can at least get it running for the car show this weekend. Then maybe it's time to do my own -8 rail from Ross Machine extrusions.

That's a real bummer. My TU rail was 3/8ths NPT for what that's worth. Is it really 1/4" NPT? That is really small.

[Skibbe]

Maybe it was machined wrong, but mine is definitely 1/4" NPT... I pulled out my taps to check.

[BadAssPerformance]

I have a few fittings in the shop... might have what you are looking for?

Which car show?

[Skibbe]

Fitting 3/8" NPT to -8 AN:
http://cgwrr.com/Mopar/FuelSystem/38NPT-8an.jpg


Don't fit:
http://cgwrr.com/Mopar/FuelSystem/toodamnbig.jpg


Check with 3/8" NPT tap, no go:
http://cgwrr.com/Mopar/FuelSystem/threeeigthstap.jpg

1/4" NPT tap threads right in:
http://cgwrr.com/Mopar/FuelSystem/onequartertap.jpg

The kicker is it looks like the wall would get pretty thin if I just re-drill and tap for 3/8".

[Skibbe]

I have a few fittings in the shop... might have what you are looking for?

Which car show?

Des Plaines Fall Fest is this weekend, show Saturday and Sunday. Got 1/4"NPT to -8 AN???

[BadAssPerformance]

I know I dont have 1/4 to -08.. might have others to step it up? 1/4 is kinda small...

wow, never heard of that event/show

[Skibbe]

New this year, big party! Being on the DP historical society board I have to volunteer Friday and Sunday... http://fallfestdesplaines.com/

I blew $12 at Summit and should have the right fittings by Friday. Small, but what else to do at this point?

[Skibbe]

Just to document the project, here's a TU fuel rail for a one-piece intake:
http://cgwrr.com/Mopar/FuelSystem/TUfuelrail.jpg


And it's worth de-burring the injector holes, I used one of these tools. You can see some flash in the hole in this photo too:
http://cgwrr.com/Mopar/FuelSystem/burr_removal.jpg

[Chris W]

Fittings required are -6AN with an O-ring. There is a recess at the end to accomodate the O-Ring seal. Do not use 3/8" or 1/4" fittings. We carry -6AN male to -6 JIC fittings in stock for $5.00 each.

Chris-TU

[cordes]

Fittings required are -6AN with an O-ring. There is a recess at the end to accomodate the O-Ring seal. Do not use 3/8" or 1/4" fittings. We carry -6AN male to -6 JIC fittings in stock for $5.00 each.

Chris-TU

That isn't a metric Saginaw fitting is it?

[turbovanman²]

It wouldn't be metric.

Nice writeup about what your doing, :thumb:

FYI, I am using a weak intank 255 pump to feed an inline 255 pump and its just enough, for now, lol.

[cordes]

It wouldn't be metric.

Nice writeup about what your doing, :thumb:

FYI, I am using a weak intank 255 pump to feed an inline 255 pump and its just enough, for now, lol.

Why wouldn't it be metric? The Saginaw fittings w/ O-rings I have dealt with are.

[WickedShelby88]

Looking good Mike:thumb:

[Skibbe]

Ordered the right fittings today (going to need a yard sale for all the extras when I'm finished...)

And got the tank buttoned up and mounted back on the car.

Here's the finished bulkhead from the outside. I did throw some argent silver on the bulkhead after clearing off some rust since everything else was going to be so shiny... The AN bulkhead fittings are installed with nylon washers that I also gooped up with some RTV sealant. Hopefully no leaks there. On this side the two original ports are plugged with some gas tank epoxy. I did run 12ga gasoline compatible wiring to the pump through the existing 5/16" port, and filled in around the wire with the epoxy. On the in tank side I used RTV, so hopefully between the two no leaks around the wiring either. I will be using the stock connector just for the level sensor.
http://cgwrr.com/Mopar/FuelSystem/FinishedBulkhead.jpg

Wiring that came with the Walbro pump was about 14/16ga, so while overkill, I ran the 12ga into the stock connector and soldered to the terminals. Other end will terminate in a radiator fan/inline pump connector outside the tank. I'll eventually run a new power feed to the pump from the ASD relay. Here's the connector apart:
http://cgwrr.com/Mopar/FuelSystem/FuelPumpWiringConnector.jpg

And here I'm ready to solder on the bigger wire:
http://cgwrr.com/Mopar/FuelSystem/SpadeConnector.jpg

[Skibbe]

And here's the finished pump assembly. While not the perfect set-up, I got tired of worrying about matching the 5/16" pump outlet to the 3/8" hose barb via the special submersible Gates rubber fuel line that NAPA was out of in either 5/16" or 3/8" varieties. Plus that stuff is $24/ft... So I saw mention of an SRT-4 company that uses -6 line for their "bottleneck eliminator kits" doing the same thing I'm doing, so I went that route... If the line expands too much sitting in fuel, it will be past race season and the braid will hold it from expanding too much, so F it and get it in the tank already!
http://cgwrr.com/Mopar/FuelSystem/PumpHanger.jpg

Oh, one more photo I took... the hanger assembly for the smaller in tank pump was different from the other single pump hanger's I've worked with on my '87 Chargers, so I had to cut out the inside of the bracket to fit the Walbro Pump with the thinner of the two included foam sleaves. Jewelers Saw made quick work:
http://cgwrr.com/Mopar/FuelSystem/JewelersSaw.jpg

Picked up new tank hangers from Rock Auto too and bent them to match the old ones and threw some primer on. Don't be scared when they arrive with a sticker that says "non turbo Omni" as they are the same length as the ones that came off my car.
http://cgwrr.com/Mopar/FuelSystem/TankHangers.jpg

[Skibbe]

Little more ghetto that I usually aim for... but here's the pump strapped in, the wiring routed through the existing 5/16" hard line, and the clamp I put to anchor the 5/16" hardline to the 1/4" hard line to add some stability for the larger pump. The zip ties are to hold the filter sock on the end of the pump since it kept popping off everytime I compressed it to go in the tank...

http://cgwrr.com/Mopar/FuelSystem/PumpMounting.jpg

[Skibbe]

It runs!

Except all that work to keep the stock level sensor... and it's reading a full tank with 5 gallons of gas in it. DOH. No leaks so far though, so at least I can go racing... just have to estimate the fuel load for the remainder of the season.

[BadAssPerformance]

Cool it runs :clap: test it with boost yet? :eyebrows:

Bummer on the gauge? Maybe a wire issue?

[Skibbe]

Cool it runs :clap: test it with boost yet? :eyebrows:

Bummer on the gauge? Maybe a wire issue?

Um, you a cop? Cause if you are, no I didn't test it into boost in third down Algonquin...

Didn't touch the wiring so thinking the float somehow got hung up on the pick-up dish... maybe a full tank will spring it loose, otherwise I could have damaged the rheostat with it going in and out of the tank so much... Now that everything including the hangers is shiny and new, it won't be an issue to get back in the tank, but I'm not motivated enough right now.

[BadAssPerformance]

Um, you a cop? Cause if you are, no I didn't test it into boost in third down Algonquin...

Didn't touch the wiring so thinking the float somehow got hung up on the pick-up dish... maybe a full tank will spring it loose, otherwise I could have damaged the rheostat with it going in and out of the tank so much... Now that everything including the hangers is shiny and new, it won't be an issue to get back in the tank, but I'm not motivated enough right now.

LOL on Algonquin? Cant wait till Wolf is repaved!

Glad its running! :thumb:

[Skibbe]

Some photos of the final set-up...

Underhood:
http://cgwrr.com/Mopar/FuelSystem/underhoodfuel.jpg

Fuel filter mounted mid-car, the 90 on the outlet swings it to the inside of the frame rail to continue on to the engine bay:
http://cgwrr.com/Mopar/FuelSystem/fuelfiltermounted.jpg

And looking back toward the tank from the filter, I tried to route it to keep everything tucked up as far as possible, so it's not the straightest, but most protected:
http://cgwrr.com/Mopar/FuelSystem/fuellines1.jpg

[Skibbe]

Looking toward the engine bay:
http://cgwrr.com/Mopar/FuelSystem/fuellines2.jpg

And attached at the bulkhead in the tank... 36+ hours no leaks!
http://cgwrr.com/Mopar/FuelSystem/bulkheadlines.jpg

[cordes]

Looks nice. Thanks again for all the pics.

[Skibbe]

Well, walked into the garage this morning and smelled gas... Few drips coming from the wiring as it exits the bulkhead. Uh-Oh!

Dropped the tank just now, pulled it all apart again... and it was the wire itself allowing gas to escape! The gas and oil friendly wire I picked up has this extra clear sheath on the outside, and gas got into that sheath on the fuel pump side and leaked right out like it was a straw.

So, I tried to solder to the existing wiring connector in the bulkhead, but being riveted to the bulkhead, it took too much heat and loosened the plastic. I'm sure that's going to leak now too. So, I need to find another bulkhead and fuel pump assembly and try again, using the smaller wire that's on the hanger. :yuck:

Should have gone with an external pump probably...

[Skibbe]

Ok, here was the culprit, I know gas was getting out through the wire between the clear outer sheath and the insulation... it was wet with gas for the length of the wire in there... Also possible is that gas was getting in the copper stranded wire itself:

http://cgwrr.com/Mopar/FuelSystem/wiringclearsheath.jpg

[Skibbe]

So, here's the second attempt. Rather than route the wire through the old feed tube, I drilled new holes, a separate one for each wire. JB Weld was used, then later stregthened with some gas tank repair epoxy to make sure any jolt to the wire didn't crack the JB weld. I also went to solid core wire, and stripped the clear sheath off of it, for the portion through the bulkhead.

http://cgwrr.com/Mopar/FuelSystem/bulkhead2ndattempt.jpg

If this leaks, I'm ordering a fuel cell. :(

[BadAssPerformance]

Is JB weld conductive?

[Skibbe]

I was worried it was, that's why it's only touching the ground wire and not the power wire.

[BadAssPerformance]

Gotcha... didnt see that!

[Skibbe]

I thought about it after smearing some JB weld on the back of that factory plug, hence clipping off the power terminal there too! Doh!

[BadAssPerformance]

Doh!

Another thought... doesnt McMaster Car sell sealing bulkhead wiring connectors?

[Skibbe]

Link?

[BadAssPerformance]

Cant find them, my bad :(

[Skibbe]

I've been searching everywhere for something like that, closest I've found is from FuelSafe for fuel cell applications and the intank wiring harness with bulkhead is ~$50!

May just have to work with a new pump hanger and bulkhead, going back to the original wiring plug.

[BadAssPerformance]

Ouch!

Yeah, a new hanger might be best

[Skibbe]

Someone must make SOMETHING though. How many cars are out there with intank pumps??

[iTurbo]

The later turbo mopars ('91+) had a sending unit with a removable bulkhead electrical connector. Made it a lot easier to braze in the new tube when I did mine.

Here it is with it removed:

http://www.turbosedan.com/spirit/DSC02767.JPG

Not sure if it's possible to install a newer hangar (w/reservoir) into an early tank though. This is the internal pump I did for my Spirit R/T (pic on page 2). Hope this helps.

[Skibbe]

Little update... Last year when I parked the car for the season I was getting some fuel leakage out of the bulkhead again. Thought it was the wiring again at the time. FINALLY had a chance to pull out the pump assembly this year and take a look. JB Weld apparently isn't fuel safe as the JB Weld on the inside softened up and was falling off.

I ordered a new fuel pump hanger from Rock Auto. Unfortunately the one I received only had a two wire plug (no fuel level sensor wire?). But I found and ordered one of these from Racetronix: http://www.racetronix.biz/itemdesc.asp?ic=BCA%2D4W&eq=&Tp=

Hopefully more progress soon...

[itoktoeatfish]

Alittle old I know, but thanks for keeping this thread updated!

[wallace]

I drill out the rivets on the factory wires and reuse the two plastic pieces. Replace the rivets with #6 machine screws. Ring tongue connectors on inside and outside. Glue it together with fuel safe silicone. Takes a bit of time but it doesn't cost $50.

[Skibbe]

That's a good idea Wallace, wish I had seen your post sooner.

I decided the Racetronix fitting was too big... I then tried to braze the extra wiring holes in the bulkhead (so I could just run the wires out the top of the tank through the spillover valve grommet) and that went south and pretty much ruined the bulkhead and hanger assembly... which lead to purchasing a brand new fuel pump hanger...

So, this time around I'm just adding one hole for the -8 AN bulkhead fitting for fuel supply and going back to the stock wiring plug. I'm also now feeding the fuel return just back into the old feed tube, we'll see if it is large enough. This is a Walbro pump which required modifications to the plastic pump housing. I carved the housing to fit around the Walbro and then secured it with two screws with washers... this is because the Walbro pump is longer than the stock replacement included with the Airtex pump assembly.

Here's the photos:

4993649937499384993949940499414994249943