IROC Wagon Project

[ssbrewskyaz]

Well I didn't do very well with my last subject (OE Exhaust Hangers and Brackets) but I'm going to give another topic another shot.

I’ve been chipping away at the things I’ve been putting off this week. To that end, today I stuffed the new fuel tank up in the straps for a test fit. As expected, I have some clearance issues with the sending unit vent line. The flippin vent line must be 5/8 of an inch; good thing is there's another normal sized vent connection so the big one is gonna get flattened and silver soldered shut.

Didn't take photos today but I will soon, of the entire fuel tank fiasco. In the interim, I'm wondering if any of you Wagon masters has a photo of what’s suppose to be going on behind the Fuel Fill Door. It may just be me but it looked like something was missing. I don’t recall it being that matter of fact but maybe I’m too used to dumping fuel in a Silverado.

There’s no splash shields or bracketry from the filler neck down to the tank. It just kinda sticks up there in the hole but looks even too Spartan for what I remember. I bought a tank that came with the fill neck already attached.

Anyway, if anyone has a clear photo of what it’s supposed to look like, I will greatly appreciate it. …

 

[Longroof79]

Scott,
I'll try to get you a picture of the gas door area today. From my recollection, it's open around the filler tube. At any rate I'll report back and let you know for sure. 🙂

 

[Longroof79]

Scott,
It seems a little too dark to get a decent picture in there. But it's just as we suspected, it's all open. No special guards or baffling.

 

[ssbrewskyaz]

Here’s what I was talking about when I asked about what was supposed to be going on behind the fuel fill door. I don’t recall it being so stark but per Jack’s comments, maybe that’s the way it is/was. Keep in mind the tank isn't all the way home on the straps this was just a test fit for clearance issues. When the straps are cinched down, the fill neck should be in the middle of the opening.

 

[84cutlassjuggalo]

IT's a very clean install. I'm hoping nmy frame off goes just as good this year. Could you give me a quick parts list on what exactally i need to do the corvett brake swap?

 

[O. D. Showtime]

You're doing some awesome work on the wagon Scott! Looks great!

I had a look at my camino gas door/filler neck and there's nothing there either. Guess GM carried that wisdom over through the line.

 

[ssbrewskyaz]

Like I said, today was about test fit for clearance and determine hose lengths etc. As previously stated, the fuel sender 5/8 inch vent line needs to go away. The remainder of the connections should be fine. This is a high pressure fuel injection fuel system so I’m using hoses similar to hoses used on 85-92 IROC Z28’s. These are all crimp fit construction that use an O-Ring as part of the high pressure seal.

The tank is a replacement for the gasoline engine. Not sure what the difference is between the gas tank and the diesel tank. Maybe someone that knows can chime in. Come to think of it, I never even asked, just assumed I needed the gasoline version.

The sender is for a 90 K5 Blazer with a 40 gallon fuel tank. 87-92 full size Blazers were fuel injected so the meter accepts a high pressure pump. The forty gallon Blazer tank was basically the same depth as the standard wagon tank. I looked over a gazillion fuel senders until I settled on this arrangement. The wagon tank is baffled; I just can’t say if it will be baffled enough. My original thought was to stuff one of the small reservoirs from a SSEi fuel injected application but I haven’t pursued that to determine if it’s the right diameter to go through the tank hole. Shouldn’t be giving away all my secrets but this isn’t a matter of National security

The tanks aren’t much to look at from the rear. Once the bumper is on, I doubt anyone will even see it at all. Just the same, and as the industry does with all the numbers matching restorations, I’m leaving the tank natural as it was when it left the plant.

Here’s the fuel sender / meter assembly. The big pipe is a 5/8 inch vent. Apparently the forty gallon tank required lots of EVAP but the stupid thing is so big it hits the bottom of the floor.

So in order to loose the vent and plug the hole, it’s going to get some heat applied. That means anything not metal either needs to be removed or protected. I preferred to remove the wire connector and wiring.

This is what the parts look like once they’re apart. You have to take your time to remove this stuff. It’s really not designed to be removed but with a couple of two by two blocks, a brass drift pin and a small hammer, here we are.

Now I need to take the sender to my fabricator so I don’t have to experiment with my welding skills on this expensive part.

 

[AndrewMrChevy]

I have installed the fuel pump from a 94 Chevy Astro in my 83 wagon for my 4.3L TBI install. I simply used a hose block off cap on the 5/8" fitting and hose clamp to seal it, I then removed the locator tab and routed the assembly in the fuel tank till it matched how the factory sender for the wagon was orientated. I have been running my for 8 months and never had any issues. Another note 86-88 El Caminos came with factory 4.3L fuel injected TBI meaning you should be able to replace the pump with pump you want and sender should function as factory. I just did not want to buy another sender and used the factory 94 Astro as is and it made for simple installation.
Great Build! I used everything from the 94 Astro, 4.3L TBI vortec V6 engine, 4L60E transmission, wiring and fuel tank and installed in my wagon.

 

[ssbrewskyaz]

Hey Andrew,

Wow, G-Body wagons in Korea! I assume that's your Hot Rod in the photo? Nice piece.

Thanks for the information. Was the Astro van fuel meter lock ring the same size as the wagon tank lock ring? That's what I was using as a gauge. I went through catalogs looking at all the lock rings that had the same part number as the wagon did until I came across one that not only fit the ring, but also had a pickup that was deep enough to get to the bottom of the tank.

You’re right about the orientation too. I didn’t cut my tab off but bent it out of the way so I could turn the sender the way I need it to be. There’s plenty of sealing pressure on the O-Ring that seals the meter to the tank. Not sure what’s different between the Astro meter and the Blazer meter but there’s simply no way I can install this with that vent line in place. It hits on the bottom of the floor and will make way to much noise if it touches anywhere when the pump is running.

What did you do for baffling? In eight months have you ever done a wide open throttle from a standing start that cavitated the pump (ran it out of fuel)? How far down does the Astro pump come to the bottom of the tank? Problem with the 4.3 TBI pumps and senders is they were in the sedan GN) or El Camino tank which is basically a pancake compared to the wagon tank. The fuel sender/meter won’t get anywhere near the bottom of a wagon tank and the pump is low pressure, i.e. eight to thirteen PSI. I’m needing fifty-five to seventy-five PSI for Tuned Port Injection.

That’s it for now; I’m off to look at photos of Astro Fuel sender/meters. Hey, by the way, do you have any photos of your stuff? Send them to my eMail if you do. …

 

[AndrewMrChevy]

Lock ring was same size. I matched up the Astro Sender and the Malibu and they were the same height, all I did is replaced the bottom strainer and installed, I think it was possible that the 5/8" vent was in a different location, but I dont remember. Sorry I dont have no pictures of when the sender was out of the tank or side by side. I was working at the Yongsan Auto Skills Center and lots of idiots just walk up smoking so was worried it would be my luck day working on the fuel tank. I did not use any baffle, and have not had any fuel off line issues, I have had it up to 100 MPH to experience the fuel cut off work. I swear the 4.3L fuel sender and 3.8 Fuel sender was the same size, except the 4.3 had the electric pump.