Jump to content
HybridZ

pics of tank with internal pump


GrayZee

Recommended Posts

What do you guys think of my tank?

 

http://members.shaw.ca/icecube/Ztank/

 

 

I cut the top off of a 240z tank, got a GM fuel sending unit from the local parts store and welded on a lazer cut flange so the pump assembly could be bolted to the tank. I'm not finished with the job yet as I'm stalled out waiting for a new fuel pump. I'm gonna be using a Holley #12-914 it's a 255LPH forced induction application pump designed for use with a Buick Regal Grand National. I figure that should solve my fuel starvation problems (especially when going around corners) Not only that, I swapped out my original gauges for Autometer ones. So rather than going with the typical Ford style 73-12ohm fuel level gauge and running resistors to get a good reading, I picked up a GM style 0-90ohm gauge to match the GM sending unit. Thus solving two problems at the same time (hopefully everthing will work out)

Link to comment
Share on other sites

Looks really nice. Do you plan to cut a hole in the floor of the hatch area to allow for access or will you just drop the tank if you need to repair or replace it?

 

What kind of baffle system do you plan to install in the tank to make sure there is alway fuel at the pickup point?

Link to comment
Share on other sites

I was thinking about maybe making a access panel in the hatch but first I'll see how it lines up in the car vs. where exactly the hole would have to be. As for the baffles the 240z tank only has one baffle plate running across the center of the tank, so what I plan to do is get a piece of 4"or 5"

pipe in a really thin gauge and weld it to the bottom of the tank so that in surrounds the pump inlet. The bottom of the tank is tapered in a V shape anyway so if I place it flush to the bottom and weld it there should still be a opening at the bottom, perhaps too big of a opening but I can always fill it using a filler rod (tig weld)

Link to comment
Share on other sites

I did the same. Except I keep the fuel lines lower that the top and used the baffle/sump from the Supra tank I got everything else from. I would use a factory sump from an EFI tank if you still have access to the inside. I can run 1 gal. with out pick up problems in a turn :D .

Link to comment
Share on other sites

I looked at your pics, very good idea. One thing that occured to me, and it still may be the best option for you.

I read you were going to use the Grand National pump.

You can use a Nissan 90-96 300zx fuel sender unit, and if you want some really consistant and good fuel pressure a twin turbo fuel pump in the sender.

I run a twin turbo fuel pump in my car, and that is without question the best fuel pump you will find. I have run my fuel pressure to 4 Bar and 25psi of boost and that pump delivered 3300cc's per minute of fuel under 83psi of fuel pressure. NO other pump I found was able to deliver that much fuel at that pressure, and believe me, I called just about every manufacturer.

The cool thing is, that you will have the Nissan sender, the Nissan pump, and I believe it would be the easiest way to mount the fuel pump inlet sock in the tank, baffel the sides in the tank for cornering, run the return stock for the sender and your in there. :D

Link to comment
Share on other sites

That's cool about the 300zxtt fuel pump being so powerful and having the baffles built in. I had no idea. However like I said, I went to autometer gauges and liked the GM idea because I could get a sending unit calibrated to funtion with a with a standard autometer ohm reading (0-90ohms) Mind you, I have no idea what kind of ohm reading you'd get from the nissan 300zxtt sending unit. Maybe it's a good match? I dunno?

Another concern was the cost. I'm betting that a brand new nissan pump is VERYYY expensive! The pump I got was $209 canadian dollars and the sending unit was just under $100CND, my guess is that the Nissan pump would be easily more than double the cost. The Walbro/Holley 255 liter per hour pump will be more than enough fuel for anything that I'm gonna do with my car.

Link to comment
Share on other sites

No, I haven't done anything more to it yet as I'm still waiting for the fuel pump I ordered. I live in Canada and sometimes ordering parts from the U.S. is a real PITA. I want to have the pump mounted in the sending unit to make sure I have the correct mounting height. Once that is figured out we'll install some sort of baffle system and weld the top plate to the tank. I'll keep you posted.

Link to comment
Share on other sites

  • 2 weeks later...
What kind of baffle system do you plan to install in the tank to make sure there is alway fuel at the pickup point?

 

Ok I figured out the baffle system. You guys are gonna laugh.. I needed a piece of 6" pipe in a really thin gauge to be able to weld it to the tank without warping it like crazy. So I came up with a piece of galvanized house venting from Home depot. It's called a fish collar lock or something like that. Anyway the size and shape seemed ideal and it was a whooping $2 :D

 

Here are the pics:

 

http://members.shaw.ca/icecube/baffle1.JPG

 

http://members.shaw.ca/icecube/baffle2.JPG

 

I had to cut a "V" section out of the pipe to allow for free movement of the float from the sending unit. I poured water in the tank and moved the tank around to see how stable the water within the pipe stayed. I was quite happy with the results. We started welding up the top of the tank up, but no pics of that yet. I'll keep you guys posted though.

Link to comment
Share on other sites

Call me stupid but how are you going to prevent the fuel from running out the bottom of that baffle in a hard corner when the tank is less than 1/4 full? Seems to me there are to many outlets to slow the flow much. :?:

 

It's an interesting idea though, maybe if the portions facing the sides of the tank where welded closed around the bottom of the baffle and the portions facing the front were left as they are it would trap enough fuel to prevent the pump from sucking air.

 

Feel free to correct any mis-conceptions I have. I'm trying to figure out the best solution for EFI in my Z and haven't fully decided yet. Leaning more towards a sump but like the idea of a surge tank as well.

 

Wheelman

Link to comment
Share on other sites

Great idea!

 

Out of curiousity' date=' have you measured the inside height of the Z tank compared to a GN tank? Will the float have full movement up and down like in the tank it was intended for?

 

!M![/quote']

 

 

I've never seen a GN tank but although the pump's application is for a GNX the sending unit is for a 98 Regal (and a few other front drive models) It seems that GM pumps all look pretty much the same and would mount in just about any other GM sending unit. I did look at the float travel from top to bottom in the Z tank and it looks like a pretty good match. In fact I wouldn't be surprised if it works better than a fuel gauge in a GM car as I've always found the fuel level readings to be rather flaky on GM's (usually you can drive 200 miles before you see it even start to move from F!) The sending unit is a aftermarket replacement that I bought from the local parts store. If anyone is interested I can get the part#

 

As for the fuel flow at the bottom of the baffles, those V notches are pretty small and I bent them so that they flare outwards and then pressed the whole piece downwards so as to make them contour with the shape of the Z gas tank. I think it'll work as well as any other baffle system in a stock gas tank. I suppose it could be improved my using a elaborate trap door system or even just some foam around the bottom of the tube?

 

After the tank is finished. I plan to do some hard cornering with very little fuel to see how well it works. Then we will all know for sure. Another thing I plan to do is fill up the tank in 4 15 liter increments and each time taking notice of what the fuel gauge is reading at quarter, half, three-quarter, and full.

Link to comment
Share on other sites

After the tank is finished. I plan to do some hard cornering with very little fuel to see how well it works. Then we will all know for sure. Another thing I plan to do is fill up the tank in 4 15 liter increments and each time taking notice of what the fuel gauge is reading at quarter' date=' half, three-quarter, and full.[/quote']

 

Awsome. I can't wait to hear the results!

 

!M!

Link to comment
Share on other sites

Might want to pressure test it before painting. I used a shop vac blowing into it and a windex spray bottle on the welds. I found a few tiny pin holes :shock:.

 

Yeah, you never know with the welding if it is "completely sealed" but that's what the POR15 is for. It'll seal up everything.

Link to comment
Share on other sites

  • 4 months later...
Ok' date=' got the top welded on now I need to sandblast it again and I'm gonna paint it with "POR14" to make sure that it is definatly sealed. Hope to have it installed soon, but for now I have some more pics.

 

http://members.shaw.ca/icecube/Ztank2/[/quote']

 

 

Updates please...?? :-D:-D I think I'm going to follow your lead there GrayZee

Link to comment
Share on other sites

Wow, I had forgotten about this thread! Hmm.. updates.. well I found out that although people put 280z tanks in 240z's it does not work the other way around. I ended up have having to get the floorpan area in the hatch cut up a bit to make the tank fit. The result is that I have to use a compact dounut spare and that I have a access hole to get at the fuel pump. Other than that the setup works good. The fuel level gauge is very acurate when it is full, empty and half full. However the 1/4 and 3/4 levels are not as good. I think this is the fault of the autometer gauge and not the sending unit. Overall I am very happy with the setup.

Link to comment
Share on other sites

  • 11 months later...

GrayZee,

You said earlier this year that the sending unit was working good for you. Would you by any chance have the part number for this sending unit?

 

Also, how is the baffle working out for you? I would like to start building my fuel tank in the next week or two, and am trying to find as many examples of baffles as possible. On yours, it does not appear that the tube you welded to the bottom has any holes in the side to let fuel in, other that the small V's around the bottom. Have you ever had starvation problems with a low fuel level because of pumping all the fuel out of the tube? Is your return line plumbed back into the tube?

 

I know that this is an old thread. Thanks for any help!

Joshua

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...