What length WEMA style fuel sending unit should I get?

[BrokeLoser]

The inside of my tank measures 15 5/8" deep.
I read somewhere that the manufacture recommends a 1" gap from sender tube to bottom. I'm guessing this is for expansion and retraction.

This is the one I'm thinking I'll get...Any suggestions?

 

[UncleWillie]

Re: What length WEMA style fuel sending unit should I get?

As long as it does not hit the bottom of the tank you are good.
The tanks may swell or shrink up to 3% due to various changing conditions.
3% of 16" is <0.5 inches.
A 15 inch sender, or shorter, should be OK.

The 1 inch gap recommendation normally applies to the fuel pickup tube.
The gap allows for 1 inch of water and crud to slosh around in the bottom of the tank without getting sucked into the fuel system.
It also means that when you start sucking air, there may still be a few gallons of fuel in the tank.

 

[dingbat]

Re: What length WEMA style fuel sending unit should I get?

I have wema sensors in both fuel tanks and freshwater tank and they work well.

Length wise, min. of 1" clearance to the bottom of the tank. Per WEMA instructions, "Anything less can affect performance, damage tank and voids the warranty".

 

[BrokeLoser]

Re: What length WEMA style fuel sending unit should I get?

Thanks for the advice guys!
One last thing...should I consider a solid state sender?

 

[dingbat]

Re: What length WEMA style fuel sending unit should I get?

Thanks for the advice guys!
One last thing...should I consider a solid state sender?

What that buys you? My sensors are going on 8 years old.....so far so good.

 

[BrokeLoser]

Re: What length WEMA style fuel sending unit should I get?

Okay, another question:
Will my current fuel gauge work with a WEMA sender or do I need a new gauge?

 

[UncleWillie]

Re: What length WEMA style fuel sending unit should I get?

The sender and the gauge have to match.
The most common units produce 240 ohms EMPTY, and 33 ohms FULL.
There are a few other not so common designs,
The numbers should be stamped on your current sender. (240-33?)

The WEMA Senders are the 240-33 standard.
The senders typically have 8 levels of output. 0, 1/8, 1/4, 3/8, ... etc.