Date: Fri, 28 Dec 2001 07:58:05 -0800
Reply-To: gary hradek <hradek@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: gary hradek <hradek@YAHOO.COM>
Subject: higher octane needs
Content-Type: text/plain; charset=us-ascii
Stan,
PV=nrT, God I hate physics. The equation says
that if pressure goes up and the volume stays the same
then Temperature has to go upas well. If you ajust
your vanagon to run at higher compression it follows
that the temperature has to go up as well. For
vanagons I think this is important. The increase in
temperature is at its worst spot, The combustion
chamber. So again, I question the merits of higher
octane. If you feel a visibly increase in performace
it is because your pressure(your absolutely right
Stan) and temperature both are rising. This may be
caused by advanced timing or possibly carbon build up
in your engine. Timing is easy to check. happy
friday, gary
--- Stan Wilder <wilden1@juno.com> wrote:
> If your van is knocking on any fuel .......... lay
> down under your van
> and kiss your heads goodbye. Detonation alone will
> ruin your heads and
> pistons if the valve seats don't drop out first.
> All vanagons with stock configuration will run on
> standard unleaded fuels
> if the AFM, timing, points etc are set correctly.
>
> Stan Wilder
> 83 Air Cooled Westfalia
>
> On Thu, 27 Dec 2001 20:25:11 -0800 gary hradek
> <hradek@YAHOO.COM> writes:
> > Chris,
> > If your van is knocking on regular and you
> add a
> > higher octane and it stops knocking what does this
> > tell you about your combustion chamber? If your
> van
> > is not knocking on regular, burn regular and save
> your
> > money for better things like something to clean
> your
> > fuel injectors because higher octane is something
> that
> > takes most of us to the cleaners. happy new
> > years,gary
> > Date: Thu, 27 Dec 2001 16:35:28 -0600
> > From: Chris Stann <ChrisS@INFORMS.COM>
> > Subject: Re: Subject: Fuel octane
> >
> > Some info contained here:
> >
> >
>
http://www.pcf.ab.ca/quick_answers/gasoline_general/octane_rating.asp
> >
> > And here:
> >
> >
>
http://www.shellus.com/products/product_info/gasoline_properties.html
> >
> > "Probably the most familiar gasoline
> characteristic is
> > antiknock
> > quality or
> > its octane rating. The octane rating is simply a
> > measure of the
> > gasoline s
> > resistance to knock. Knock is the sound made when
> the
> > fuel/air mixture
> > in
> > the engine s combustion chambers ignites by itself
> > (auto-ignition),
> > either
> > before the spark occurs or in front of the flame
> > already started by the
> > spark plug. Advancing ignition timing increases
> the
> > tendency to knock.
> > "
> >
> > It says absolutely nothing about the higher-octane
> gas
> > burning at a
> > higher
> > temperature. It does say, however, that engines
> with
> > higher
> > compression,
> > such as Euro-WBX, or advanced timing, such as
> mine,
> > will benefit from a
> > higher octane gasoline. Also, engines with
> combustion
> > chamber
> > deposits,
> > such as any old WBX, will have slightly higher
> > compression ratio, hence
> > the
> > benefit of increased engine longevity from
> > higher-octane gasoline.
> >
> > All of this should be considered along with the
> > driving environment.
> > It
> > seems that an engine under higher and prolonged
> loads,
> > such as a
> > hill-climbing Westy, is probably going to benefit
> from
> > e more
> > expensive
> > gasoline.
> >
> >
> > Chris.
> >
> > __________________________________________________
> >
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