Heating return line?

[The Warden]

Hello!

I know that, if you're running straight vegetable oil, it's ideal to heat up the fuel feed line and the fuel tank. Is it also a good idea to heat the fuel return line?

Thanks!

[Lobstah]

Warden,
I think that depends on the amount of heat you're feeding the tank. Unless it was VERY marginal, I don't think it would be necessary, but I plan on running all of my lines inside a PVC bundle along with the coolant lines I'll be using to heat the tank.

I'm leaning towards NOT using one of my stock tanks, but using a third tank in the bed for the WVO.

1) We already have plans for that on the 6.9 site, by using a second "Y" in the fuel lines we can route returns and feeds and switch from inside the cab.

2) For my heating element, it will be MUCH easier to plumb the tank in the bed. I plan on feeding it with a tap from the heater feed, and putting a regular heater control valve inline along with a temp sensor for the tank. That way I can monitor the temp, and also control the flow of coolant through the tank the same way we control the flow of coolant through the heater core.

Lob

[GraemeDiesel]

I think it would be a worthwhile to heat the return line in case you got a batch of oil that wanted to thicken on a cool day.

[Lobstah]

I was thinking that if it's heated to say 120 deg, and it's running from the tank to the engine inside a pvc pipe along with the coolant plumbing, I'd just run it back through the same pvc pipe...

Lob

[TCH777]

when the fuel runs thru the engine block fuel passages it heats things up quite a bit!

Tim

[The Warden]

Lob, your plan to put a third tank in the bed makes sense...I"d probably go that route myself, except that I don't want to lose any more bed space than I already have. I fill my bed up to capacity on a fairly regular basis...

The idea of routing both fuel lines through a conduit of sorts makes sense. Do you think that the lines wrapped around the fuel feed (like Greasel's three-way-hose setup) would heat up the return line as well?

[ QUOTE ]
when the fuel runs thru the engine block fuel passages it heats things up quite a bit!

[/ QUOTE ]
...except that IDI's don't have the engine block fuel passages that PSD's have. [img]/ubbthreads/images/graemlins/smile.gif[/img] All fuel lines on an IDI are external, except for the injectors themselves...

[GraemeDiesel]

I think what I'd do is take the coolant hoses and fuel lines going to the oil tank and bunch them together and wrap tape around them. The hose in hose system and 3 hose syestem that greasel sells don't really seem worthwhile to me. [img]/ubbthreads/images/graemlins/shrug.gif[/img]

[The Warden]

Yeah, but will the average black rubber hose conduct heat enough (especially through two layers) to heat up the fuel enough to really help? I at least thought that the big advantage with the Greasel setup was that they use thin plastic that radiates heat better.

Or can plastic fuel/coolant hoses be readily acquired? BTW, if this makes a difference, I've got metal fuel lines right now (they switched to the plastic lines with the quick-connect fittings in '85)...

[Lobstah]

I plan on running the "variable" heat option in the tank, with a gauge to monitor, so my real concern is keeping the fuel from cooling down to much on it's trip up to the engine, and I plan on using metal lines to do that, so running along side a rubber hose full of coolant should do the trick just fine.

Lob

[GraemeDiesel]

I think that rubber coolant hose will still radiate plenty of heat.

Air brake like can be used for fuel line.