What year gas tank do I have?

[Jeff G 78]

Even after doing the POR15 treatment on my late 260 tank, I still have issues on the race track. I'm pretty sure the pickup screen is clogged and I can't get to it or even see it, so I went to my parts stash at my dad's house in Ohio and found a tank that I've had for close to 20 years. The tanks is very clean inside, so hopefully I can use it in my '74 with round top SUs. The tank came with a parts car I bought way back when, so I don't know what year it is.

The 260 tank is still in the car, so I can't compare them side by side yet, but from pictures I took a few years ago, here are my observations.

On the outside, it looks about like my '74 tank. The sender is in the front and the large and small vents are stacked on the back wall. The only external difference is that the drain is near the big end, while my '74 tank's drain is in the center.

The inside looks similar to my '74, but has a shorter divider wall and I can see the top of a cylindrical baffle around the pickup.

I'm guessing it's a '75 tank due to the baffle, but I need to know for sure so I can locate the proper sending unit. The sender that was in it is slightly different than the one from the '74, but still has the same nailhead-style wiring terminals. If it is from a '75, is there any issue with using a FI tank in a carbed car?

[sblake01]

A non baffled tank in an FI car would be problematic but I don't see how it could be the other way abound. I recall from searching the junkyards for a tank that the tank that looks like a 260Z tank but has the EFI baffles is a 75-76 280Z tank. My gut feeling is that it would work for you.

[240260280z]

Here are some old pics from my HD

[Jeff G 78]

Hey Blue, what is the fist picture? It looks like a vent nipple at the opposite end from the filler neck. My late 74 vents are both in the back wall. Otherwise, the inside looks fairly close to mine.

Here's the inside of my 260 tank after POR15.

Here's the outside. You can see the vent hose hanging off the back.

[240260280z]

Hi Jeff,

The first pic is a corner vent that had to be re-soldered due to a leak we found.

It is located in rear left side of tank.

[Jeff G 78]

Blue,

That's why I asked. If that is a late 74 tank and mine is a late 74 tank, why are they different? This is one of the things that bugs me about owning a 260. Parts all over the car seem to change randomly throughout the model year. All of the hoses and the tank appeared to be original when I got the car and it had been parked for 15 years or so before that, so I doubt the tank was ever changed.

[Jeff G 78]

The more I compare Blue's pics to my pics, I see lots of strange differences between two "1974.5" tanks. For one, the wall's mounting ears are reversed. My tank's ears are folded towards the filler neck and his are folded away from the neck. Also, there are no flow gaps at the bottom of his and there is no hole through the wall for the return line outlet.

Are these really both '74.5 tanks???

[geezer]

I don't see anything that will prevent you using the tank from your Dad's but the sending unit will most likely need to be matched up because of the different possible tank capacities. This page taken from the "Outline Specifications" manual, which explains the transition years of '74, '74.5 & '75 may help in some small way to differentiate the year/model usage of your tanks. Just curious, how important is it to have a working fuel gauge? Can the team determine closely enough, how far you can go on a tank and do the math on pit stops?

[Jeff G 78]

Ron, We have done two races and lots of track days without a fuel gauge, so it's not a huge deal. It's one of those things that is low on the priority list, but would be nice to have.

I'll take a look at the doc you attached, thanks. BTW, I would still like to get the spare dizzy grommet from you at some point. No rush.

EDIT: I just read the document. It sounds like the only real change that affects me is the outlet pipe size, which isn't a big deal. I'm thinking Blue's photos might be of an early 260 rather than a late 260.

What do they mean when they say "reserve tank"? Are they talking about the vapor tank?

Edited March 31, 2011 by Jeff G 78
added info

[geezer]

BTW, I would still like to get the spare dizzy grommet at some point. No rush.

No problem, you can have one of the Martys pick it up or if you want meet me next week when I'm over. Just not sure of the day or time yet. I'll PM you.

Edit: Yes, I've seen a few instances where Nissan refers to the vapor tanks as reserve tanks.

Edited March 31, 2011 by geezer

[Jeff G 78]

Sweet. Thanks Ron.