quote:Originally posted by comp2:quote:Originally posted by PanteraDoug:
OK. This discussion brings up two more subjects that I see.
1) on Tennessee Tims plumbing system with the Weber carbs and a return line to the tank, how do you protect the carbs from receiving more than 3-4 psi of fuel if the regulator is behind them and not in front of them?
2)considering that we are returning hot fuel to the tank with the return line, how do you protect the tank itself from being susceptable to a flash explosion? Particularly considering that liquid fuel under pressure is going to have a tendency of atomizing, i.e., mixing with the air into a combustible mixture?
This is what I was saying about using the fuel tank itself and it's contents as a heat sink.
I understand that the EFI systems use this but I don't just go and presume that all is well and good.
What happens when the tank is nearly empty and you are spraying hot fuel back into the tank? The Pantera tank is in VERY CLOSE PROXIMITY to the exhausts?
I guess I would question where the additional heat is coming from? The engine? If the regulator is away from the engine would it make much difference?
It could give you the opportunity to run a fuel cooler to reverse the process?
In the case of the "Webers" when the engine is shut off, the heat rises out of the engine, through the runners in the manifold, then up through the carbs.
Draw a schematic. You will see that you have just drawn a heat sink.
How hot does that fuel get? Don't know. It does effect the fuel pressure reading in that it goes from 3-4 while running to about 4-1/2 psi right after the engine shuts down.
I do not think that my set up is unique.
If there is an issue it is with the stock Weber inlet valves. They are not consistently good.
This entire subject was a dead one as far as I was concerned until Tennessee Tim brought it up and decided a return on his kit Cobra was the solution.
In my case, "if it ain't broken, don't fix it", but it is something that caught my interest "as a point of interest".
I don't see a huge difference between a Pantera with a metal fuel tank and having a return added and a current production vehicle with EFI a return and a high impact plastic tank BUT I have never seen this discussed and there is a difference.
Thus is the point of my post.
