Fuel Sending Unit

[69hemibeep]

Since I received my new tank and sending unit for the Valiant project I thought it would be a good time for a tech session. I was going to do this anyway to make sure my gauge read close to correct. First the parameters for our sending units are 8.6 to 10.6 ohms at full. 61-85 ohms empty. I bench tested my unit at 9.5 full and 83 empty. If you drop it below the sock it goes off scale but that's ok it would be below the bottom of the tank. Next I installed the unit after bending the pickup because it hit the bottom of the tank prematurely. Then I tested at empty and got 79 (the float was resting on the bottom) which is in range, then full using a stick to hold the float all the way up and got 9.6 which is also good, no adjustments needed. Note, an A-body tank is taller than a b-body so the float comes closer to the top and can be adjusted on a b-body. If your readings are off some what you can bend the float rod to adjust, if its way off get another unit

 

[Jim S.]

Good job Spongy. Hey do you remember this fix from awhile ago? Apparently there are only two small spots for the float arm to get it's ground and that goes bad a lot. When I replace my tank this spring, I am going to do this just for insurance with a few strands of copper wire.....

 

[abodybill]

Just in time as I got my new sending unit in yesterdays mail for the race car and will check it out.

Looks just like mine SS 3/8 supply.

Thanks Bob :wave:

 

[69hemibeep]

Good job Spongy. Hey do you remember this fix from awhile ago? Apparently there are only two small spots for the float arm to get it's ground and that goes bad a lot. When I replace my tank this spring, I am going to do this just for insurance with a few strands of copper wire.....View attachment 4601View attachment 4602

I do remember that, And will add that to mine

 

[Roadcuda]

Question Bob. I've heard many times that you can adjust the arm but I've never seen exactly where on the arm or how you make the bends for it to work right and without causing other problems with the unit.

 

[69hemibeep]

Question Bob. I've heard many times that you can adjust the arm but I've never seen exactly where on the arm or how you make the bends for it to work right and without causing other problems with the unit.

Use two pair of pliers and bend the rod between the sending unit and the float. The closer to the unit the more adjustment to the float can be made.

 

[Roadcuda]

Use two pair of pliers and bend the rod between the sending unit and the float. The closer to the unit the more adjustment to the float can be made.

Ok I got that, but do you bend it up or down? Or does that depend on what the ohms reading is? And I guess the critical question is how much do you bend it?

 

[Basketcase]

seems like alot of trouble when you're using a Moon tank anyway.....

 

[Steve]

Excellent post Bob,pics make it easy to follow you old guys know your stuff.

 

[69hemibeep]

Ok I got that, but do you bend it up or down? Or does that depend on what the ohms reading is? And I guess the critical question is how much do you bend it?

Let say your float is at the bottom of the tank and you at 50 ohms you would bent the float up so the sending unit will drop further. If your at the stop on the unit you would need to make your bend between the stop and the unit. The stop is a metal tab at the top and bottom of the unit that keeps the float from spinning 360 degrees

 

[69hemibeep]

seems like alot of trouble when you're using a Moon tank anyway.....

:toetap:

 

[69hemibeep]

Excellent post Bob,pics make it easy to follow you old guys know your stuff.

That was a backhanded compliment do you need slapped again :lmao:

 

[Basketcase]

:toetap:

gotta cover for Ray when he's working ....:CHASIN312:

 

[Steve]

That was a backhanded compliment do you need slapped again :lmao:

:toetap: :toetap:

 

[4spd69RR]

Agreed, good post Bob!

 

[ACME A12]

I do remember that, And will add that to mine

Now that looks like good insurance. Any particulars on wire gauge and or location?

 

[Jim S.]

Now that looks like good insurance. Any particulars on wire gauge and or location?

No the guy never said what he used. Looking at the pics, I would guess about 6 or 7 strands of 30 gauge. As you can see he twisted it together and spot soldered it in a few spots. What you could do is take a piece of 10 gauge stranded and strip off the insulation which would eventually melt in the gas. Probably shooting for about 22 gauge after the jumper is made. Have to use your own judgement, just don't use a piece of 22 gauge solid because it would break from the movement.

Strand wire gauge chart. http://www.seas.gwu.edu/~ecelabs/appnotes/PDF/techdat/swc.pdf

 

[Big John]

You know might work real nice is a length of the braided wire they use as a desoldering wick.

 

[Jim S.]

You know might work real nice is a length of the braided wire they use as a desoldering wick.

Yeah good idea. I have a couple spools of that, some coated in flux and some not.

 

[69hemibeep]

Just did it to mine, kind of a pain in the ass to tin the new tube even after scuffing it but I got it