That's what I'm talkin' about!

 

The GM modules are not sealed units so with a full (or near full) tank, fuel will just flow in. My question is once you get below all the openings how do you fill the bucket (module) with fuel? Did you drill holes at the bottom so it can fill or are you relying on fuel from the return line to fill it? Without a jet type pump I don't see any way it can get. Enlighten me please.

 

Some compromise by cutting holes in the buckets or doing away with them altogether. So the level in the bucket is whatever the tank level is at. In other cases the venturi/siphon pump is driven by the return side of the intank FPR. So this feature is not lost when the pump is swapped. In my case the venturi pump was driven off an small secondary outlet on the bottom of the factory pump. So the Walbro swap killed the venturi pump.

So are you talking about something similar to my factory pump or something like the Walbros that have been modified with an extra outlet on top to connect a line to drive the venturi/siphon pump that keeps the bucket filled? They are 2 different types of pumps. The factory pump is designed so that the venturi feed is not affected by the main outlet line pressure.

The reserve capacity of the existing buckets may not be adequate to handle 2 pumps. Particularly the returnless designs that also have the large filter in the bucket. Maybe the additional pump, if required, could have it's own full-featured bucket.

 

DrX I left kept my bucket intact and figured the return line would keep the bucket filled, and overflowing with as long as the walbro is pulling fuel and sending it to the rails. Obviously this isn't a possiblility on returnless.

shoeboxrich, our trucks have return lines up to 2003 and then they go to returnless systems.

 

i'm very interested in a 99-02 return style setup that functions %100 like stock, i refuse to hack up my bucket and use a generic 255lph pump.

 

On the returnless setups the intank FPRs also dump back into the bucket.
Won't be much if anything going back to the bucket under high demand situations though.

Without the siphon pump you still have to keep the tank 1/4 to 1/3 full minimum. The siphon pump takes care of any air that is sucked up under scavenging(low fuel) conditions, because it is separated from the fuel as it flows into the bucket from the top of the siphon tube.

 

Ahhh, I see. Thanks for clearing it up.

 

I really like the dual intanks being that one is on a hobbs switch. also you can switch one pump running all the time to the other one, kind of rotating them. Im sure that the demand would be good for a twin 255 setup since 340+ twins are getting up there in price.

keeping the tank 1/4 full kind of sucks too especially with the added weight at the track, to our already heavy *** trucks. anything below that and my truck wont even idle.