[V8] returnless fuel systems and vapor lock

Tony and Lillie tonyandlillie1 at earthlink.net
Wed May 17 22:45:07 EDT 2006

The good thing about a returnless system is that it doesn't constantly 
circulate the fuel through the hot engine bay. That is one of the reasons 
they switched, among others, I'm sure.

Tony Hoffman

----- Original Message ----- 
From: <NicolCS at aol.com>
To: <v8 at audifans.com>
Sent: Wednesday, May 17, 2006 9:11 AM
Subject: Re: [V8] returnless fuel systems and vapor lock

> Wouldn't a returnless fuel system be more likely to vapor lock?
> No, the fuel is under about 50 psi pressure which raises the boiling point
> for one thing, plus the problem with vapor lock is that mechanical fuel 
> pumps
> don't pump well when there's pressurized vapor in the lines or pump.  With 
> the
> electric pump submerged in fuel in the tank it easily compresses the vapor 
> and
> blows it through an injector.  It might run funny for a few seconds but 
> won't
> disable the motor.  A return system works better 'cause the hot fuel is
> cleared right out and back to the tank but returnless systems are well 
> proven too.
> Craig Nicol 

More information about the V8 mailing list