What temperature is the fuel in the return line?

[Headshot zod]

Just a curiousity question. Roughly how hot is the fuel when it returns back to the tank?

 

[JLEONARD]

Good question. I can't answer that one, but I can tell you that I have a fuel cooler on my boat 6bta (P pump). It is a small tubular unit that is sea water cooled. I can put you with a source for one if you are interested, just send me a pm.

Jay

 

[1stgen4evr]

Generally speaking, after enough time to reach full temperature on the engine and components, the fuel temperature will be pretty much the same as that of the thermostat controled engine temperature, whatever that is.



Since I am not a boater, I can only guess that the reason for cooling the fuel on a boat is to keep the entire fuel supply from getting to engine temperature as it would after an extended period of operation.



James

 

[JLEONARD]

James, yes you are correct. My two fuel tanks are located in the same compartment as the engine... they are about 30 inches away and would eventually heat up to the compartment temperature which may get close to around 130 degrees (spec is 30 deg over ambient).

Looking at my boat engine's specs, it is rated at 270 hp when the fuel is at 77 deg F and 260 hp when the fuel is at 104 F.

So fuel temp does make a difference.

I don't know what Zod has in mind that's why I offered the source.

Jay

 

[Headshot zod]

Thats interesting.