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"Correct" fuel-line-to-tank attachment


strotter

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I've done a couple of searches on-site here, but I haven't found anything that directly answers the question: what's considered the "correct" way of attaching oversized fuel lines to the tank? I've got a '72 and am pulling the tank to attach 1/2" feed and 3/8" return (for an injected 327), but don't want to weld if I can avoid it.

 

On a related note, are the injected engines here running the remote reservoir per JTR fuel-injection book? If so, did you fab them yourself, or adapt some existing component? I have an old oxygen cylinder (about 1 liter capacity) which might work for me, if it turns out to be necessary/wise/useful.

 

Comments? Suggestions?

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I used a hole saw to make a hole near the sending unit for a -8 bulkhead fitting. I bent a piece of 1/2" AL tubing to reach the bottom/rear of the tank. The bulkhead fitting is sealed with a fiber washer on the inside and epoxy on the outside. No welding required!

 

Don

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Guest Anonymous

You could also just use a surge tank. Do a search on the web under it. A surge tank is a small tank that is feed by a low pressure pump, the tank would go where there was room for it, but I've seen it done putting it where the battery is and relocating the battery. A high volume pressure pump for EFI is used from the tank to the motor. This allows you use the stock lines and yet still keep the EFI fed. Thats a pretty big fuel line, what sort of HP are you looking to support?

 

Regards,

 

Lone

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Desktop Dyno tells me I'll be in the just-less-than 300 hp range with an LT-1 cam / block huggers / dual 2.5" exhaust, etc. A mild build, I know, but I'm prone to fiddle with things, and if at some later date I want to replace the LT-1 with this Comp Cams XR270HR I have laying around, in conjunction with some other external mods, DD2k has me in the 400+ hp range. The *last* thing I want to face is dropping the tank again, it's a job I just *hate* to do. So, if I'm back there anyway to add the return line and reservoir (I guess what you referred to as the surge tank) I may as well overkill now and not worry later.

 

An idea I thought I'd rip off came from the JTR EFI Swap book. It's basically a little open-topped box with walls 1" or so high. One side is open (toward the nearest side of the tank) to allow fuel to enter. When the fuel sloshes away (to the far side of the tank) the little reservoir holds just a couple of ounces, enough to feed the engine until the end of the turn. I was thinking I could pull off the sending unit, drill a single hole, solder the 1/2" aluminum line to it, and then solder the mini-reservoir to the end of the aluminum tubing. It would, of course, need to be sized so as to fit through the existing opening for the pickup, as well as to make firm, flat contact with the bottom of the tank. For the return, I was thinking I could use the existing 5/16" pickup fitting.

 

Comments?

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Desktop Dyno tells me I'll be in the just-less-than 300 hp range with an LT-1 cam / block huggers / dual 2.5" exhaust, etc. A mild build, I know, but I'm prone to fiddle with things, and if at some later date I want to replace the LT-1 with this Comp Cams XR270HR I have laying around, in conjunction with some other external mods, DD2k has me in the 400+ hp range. The *last* thing I want to face is dropping the tank again, it's a job I just *hate* to do. So, if I'm back there anyway to add the return line and reservoir (I guess what you referred to as the surge tank) I may as well overkill now and not worry later.

 

An idea I thought I'd rip off came from the JTR EFI Swap book. It's basically a little open-topped box with walls 1" or so high. One side is open (toward the nearest side of the tank) to allow fuel to enter. When the fuel sloshes away (to the far side of the tank) the little reservoir holds just a couple of ounces, enough to feed the engine until the end of the turn. I was thinking I could pull off the sending unit, drill a single hole, solder the 1/2" aluminum line to it, and then solder the mini-reservoir to the end of the aluminum tubing. It would, of course, need to be sized so as to fit through the existing opening for the pickup, as well as to make firm, flat contact with the bottom of the tank. For the return, I was thinking I could use the existing 5/16" pickup fitting.

 

Comments?

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Hey Scott

I used the JTR method for my LS1. I feed the the little box with a low pressure pump and used a high pressure pump to feed the pressure regulator. My pressure has to be set at 59 PSI. the return from the regulator feeds back to the little box, and a return line from the little box feeds back to the Z's gas tank. I used the stock gas line to feed up to the motor, and have no trouble feeding the 300 RWHP. I used and electral explosion proof box for my little tank, it had four 1/2" threaded outlets. the box itself went together in two pieces that threaded together. I used and epoxey sealer on the threads, installed all the fittings and then air tested to 40 psi. It's been working great for a year now. I also installed a fuel filter between the Z's tank and the little tank, low pressure type. Then a high pressure filter just before the motor. cheers.gif

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I did like Mike kZ and welded a sump on. Again, this required welding. When I did mine I drilled holes in the bottom of the tank instead of cutting it out. This effectively turned the bottom of the tank into a baffle to combat fuel starvation.

Scott, you live in Lodi. Did you come to the Rio Vista meet?

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Dan, yeah I was there. My girl and I had a great time, took lots of pictures. Kind of a mixed bag for the morale, though: V8Z's are very cool, but man, there are some *really* nice cars out there. To see them in person gets you all excited to get to work, and at the same time kind of intimidates you. At the time of the meet, I was just starting to prep my engine compartment. I was going to clean it up, take out the unnecessary stuff, call it a wrap. Now, I'm painting it to match the body color, carefully cleaning the brake lines and other hoses, removing things to avoid any chance of overspray, I'm going to have to disassemble the clutch and brake cylinders so I can repaint & clean as necessary, I'll need some better-looking valve covers, and some kind of trick intake system, and maybe braided lines, and the bracket for the electronics needs to look factory, and so on and so on and so on... I mean, it'll look much better when I'm done, but "done" is starting to look like September or October, not May or June any more... Sigh.

 

It's all good, though; next year, if they decide to do another get-together, I'll darned sure be there with something I can be really proud of. Or, maybe the year after.

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