Engine/Transmission (1998.5 - 2002) Vulcan Draw Straw

[rweis]

Pump in the tank comment:



Bosch test stand calibration psi to the VP44 is 13. 5 psi. Does the in tank pump meet that criteria at all volumes?



Less than 1/3 tank possibility of drawing air with the DrawStraw:

A possibility, so you are recommending to not go below 1/3 tank to go?



1/3 tank would be the 10 gallons where the "low fuel" light comes on + 8 gallons (1/3 of normal fill up). In another thread we tried to figure out how deep the fuel is when the "low fuel" light comes on. We figuered about 3. 5 gallons / 1" in the last 3 inches of the tank shape giving about 10 gallons where the "low fuel" light comes on. The tank shape is not regular inside at all. An additional 8 gallons would probably give about +2" of fuel to the already 3" of fuel giving about 5" of fuel depth (when more than 3" there are fewer inside tank structures giving more fuel per inch of verticle depth).



1/3 fuel to go on the gauge is not an unreasonable depth to be totally assured at all times, mountains, steep driveways, high acceleration, high stopping forces, in any situation.



The worst case would be to hang the truck verticle from a cable to make the fuel tank verticle and then 1/2 tank would probably keep the DrawStraw covered in fuel, so you may be right.



18 gallons would be 1/2 of total tank volume that would indicate 1/3 fuel remaining on the gauge due to the last 10 gallons not indicating on the gauge.



In the other thread about the DrawStraw and fuel sump a couple of members are experimenting with a fuel sump for size, depth, location.



Does anyone have any idea how aftermarket tanks (AdvancedFlow etc) have what shape on the inside? Do they have baffles, sumps, where is the sump if it exist?



Bob Weis

 

[jeepit]

AFoulk,



With an AirDog your aeration problems are solved as that is what it is designed to do - remove the air from the fuel before passing it on to the injection pump. Does not matter whether or not you have the factory suction tube or the Vulcan (installed correctly, not cut off too short). If you have the factory suction tube and install an AirDog you are wasting time and money on the Vulcan draw straw - simply not needed. Trust me, I've driven my truck for 140,000 miles with the AirDog putting out 19psi at idle and WOT and it is drawing the fuel through the factory suction tube.



Godspeed,

Trent

Trent, Did you bypass original engine mounted filter or are you double filtering?

 

[blacksheepdiesel]

jeepit,

Bypassed. I use a 2 micron filter on the AirDog and I think 5 micron is the lowest I've found for the stock filter so double filtering like that would have no advantage and actually is a disadvantage because of the restriction going from 1/2" hose to the already restrictive factory filter housing. A guy could install the AirDog and then another remote filter head with 1/2" fittings and use a 5 micron on the AirDog and then a 2 micron on the remote. Even though the AirDog filter is small it lasts me typically 30,000 miles before the psi starts to drop and then I change it.

Godspeed,
Trent