Former VWDieselParts.com Forum

I'm putting together the plumbing for my son's Rabbit vegy conversion. Using the standard pollock valves at the pump and a 6 U.S. gallon marine tank in the trunk, I want to run the heater lines side by side under the back seat, along the floor, to a separate heated filter in or near the engine compartment.

My question is: using Fatmobile's return line to supply line concept, could I have vegy flow from the return port at the pump, through the pollock, into one of heater lines coming from the vegy tank, where it would go back to the vegy tank collecting more heat. Then at the top of the tank, connect to the supply with a tee, and return. Would this work okay?

Let me see if I have this straight.

into one of heater lines coming from the vegy tank, where it would go back to the vegy tank collecting more heat.

I don't quite understand this.
Into one of the heater lines, coming from the tank... so you want 2 HWHs, one coming from the tank and one going back to it?
I connect my retrun line to the output of the vegy filter.
This allows me to backflush the filter every time I shutdown. Storing a thinner fuel (vegy/diesel flushings) in the vegy filter, that allows a quicker/earlier switch to vegy.
It also helps keep the vacuum down and the pump from having to pull so hard. Pulling 4 times less through the filter really matters, especially when you first switch to vegy and the fuel is a little thick.
I think all of this overides any benefit of higher fuel temps that might be possible.

Yes, it was an idea I had to get the vegy warmer, but I forgot about the filter backflush idea. The double HWH line to tank might slow flow of coolant too. I noticed in my saved notes that you had a 10"section of HWH line before your pump and after the filter, so I'll try to get that plumbing in place too. Thanks for the reply.

I'm not sure it's 10", it might be a little more.
Also, I run coolant from the engine in a 5/8" piece of heater hose. When it gets to the HWH it splits the flow.
Half goes back to the tank and half goes toward the filter.
This doubles the coolant flow and provides plenty of heat to the filter and the tank.
Because of this I have to return coolant at 2 places. I think my website has a picture of the stock metal coolant line with the extra nipple on it.
The coolant that heats the filter and stretch of HWH that runs to the injection pump, is returned down by the waterpump.

Sorry for the late reply. Your heating system is very interesting( more saved notes). I should have the conversion done within the next week or so once I get the hardware together.