I should add:
As the injectors heat up beyond their design temperature they deliver less
fuel which leans out the mixture. Lean engines run hotter which heats up
the injectors more which heats up the fuel more. As the fuel heats up its
vapor pressure goes up. When the vapor pressure exceeds the boost pump
pressure it makes bubbles and bubbles make VAPOR LOCK.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Glenn Ashmore" wrote in message
news:rJLOe.24$dm.12@lakeread03...
I am afraid the returned fuel does a lot more than just remove air bubbles.
Routing it directly back into the engine is not a good idea. The extra
fuel cools the injectors. When it does it gets hot. When it gets hot the
specific gravity goes down and when the specific gravity goes down it
contains less energy per unit of volume. The engine's power rating
decreases about 2% for every 15C increase in fuel temperature. The hot
fuel also does not cool the injectors properly so they no longer deliver
the correct amount of fuel.

The extra fuel should be returned to the tank to cool off and the tank's
return fitting should be located away from the pick up for the same
reason.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Franz Eckert" wrote in message
. dk...
Hi there.

Nope, if you make a T piece on the return fuel, you won't need more that
one.
The return fuel is only there because you need a way to get the air out
of your system, once it is out, you can simply return the (return) to
your fuel system.
So if you put the flow sensor on the intake from the tank, and then make
your return system from the pump go in after the flow sensor, you would
have an accurate measuring. But offcourse you would have to remember to
switch the return system back to the tank if you change filters or
anything else that lets air in to your fuel system. Everything depends on
that you don't have any leaks in your fuel line.

Wkr
Franz
skrev i en meddelelse
oups.com...

Franz Eckert wrote:
Hi there.

Goto www1.uk.conrad.com and search for component number 187151 - 14

That should do the trick, don't you think?
Looks interesting. With a diesel engine you would need 2 - a second
one to subtract the fuel returned to the tank by the spill line????