injector resistance

[Gary Derian]

Well said! Mr. Harris.

Gary Derian <gderian at cybergate.net>



>If it ain't vapour it ain't agonna burn.  Period.  See laws of physics -
>combustion section.
>
>Ideally, for maximum power, fuel "droplets" will enter the cylinder under
their
>boiling temp, having absorbed the maximum heat from the mixture possible
>(thereby making it as dense as possible), and will then completely vaporize
>after the intake valve closes and prior to ignition.  The rising cylinder
>temperature aids this process - but the rising pressure raises the boiling
>point and hinders it.
>
>Now, if you are not at full power, Wide open throttle - V E Schmee Eeee.
For
>maximum power, fuel/air mix is like teenage sex - quantity matters more
than
>quality.   At less than WOT, the loss in VE incurred by external partial
>vaporization (boiling) of fuel is more than made up for by the increase in
the
>quality of the mixture.  Two basic ways to increase the quality of the
mixture.
> Add heat to the mixture such as in exhaust crossovers or pre-heating the
fuel,
>and add turbulence (carboration) such as swirl ports etc.  The trick is to
>greatly improve the part throttle without hosing the full throttle ( this
has
>been left to the class as an exercise for the last 100 years ).
>
>BTW the reason Honda chose 70 degrees C is not particularly magic.  It's
>because that's the temp that results from pre-heating the fuel with the
engine
>coolant.  This, coupled with raising the intake air temp gave them bettor
>mileage and response.  Vee Eee Scmee Eeee - with you have a turbo to shove
the
>air in, the small difference in VE this results in was swamped by the
turbo,
>and the mileage increase gave them a competitive advantage (pit stops yu
know).
>
>If the first ingredient ain't Habanero, then the rest don't matter.
>Other Obsessions: Ferro-Equinary , 1972 "Killer Whale" Mustang
>Currently Interred in the Peoples Democratic Republic of California -
Stalag
>Montclair
>Puck da guns - ban Politicians!!!!!
>Robert Harris <bob at bobthecomputerguy.com>
>
>
>-----Original Message-----
>From: Michael Baxter [SMTP:MBaxter at compuserve.com]
>Sent: Sunday, January 11, 1998 11:57 PM
>To: Blind.Copy.Receiver at compuserve.com
>Subject: Re: injector resistance
>
>"Gary Derian" <gderian at cybergate.net> writes:
>
>>> I believe Honda's last turbocharged Formula 1 engine heated the fuel to
>70 degrees C.
>Gasoline has an end point around 300 degrees.  If you heat it to 150 or
>so, much of it will
>vaporize as it comes out of the injectors.  Heat it to 300 and you can
>be injecting vapor.
>Under pressure in the fuel rail it would be liquid.  As it flowed past
>the injectors, it
>would flash into vapor.
><<
>
>Hmmm..I wouldn't think you would want the fuel to vaporize if it can
>be helped? Vapor takes up many, many more times more volume than fuel
>in micro-droplet form and will reduce the VE.
>
>There's a local injector guru here doing extensive research on injector
>spray patterns and droplet sizes on a dyno and in a lab using lasers to
>measure the the droplet size. When ever I drop-in for a visit, it's all I
>hear. "Droplet size...droplet size...droplet size."
>
>
> -- Michael Baxter, MBaxter at Compuserve.com
> http://ourworld.compuserve.com/homepages/MBaxter
> From Reno, NV USA on 11-Jan-1998