: Re: How Much Compression
> "Frogeye" used 17 as an outrageous example that even in Death Valley it
> would be hard to believe the 250psi reading.
> Also, you guys need to take into account the rarefaction of the charge as
> it moves through the throttle area and the manifold....
>
> Dave@Taos Garage Annex in Albuquerque
> '59 AH :{) '54 BN1
>
> ----- Original Message -----
> From: "David N Waldmann" <david@vermonthardwoods.com>
> To: <spridgets@autox.team.net>
> Sent: Friday, November 02, 2001 12:56 PM
> Subject: Re: How Much Compression
>
>
> > Well there is a direct relationship between the two. As (I believe it
was
> > Ron, a little hard to tell in this message) says, the heat gained by
> > compression does add a factor which may be difficult to determine. If
you
> > had a perfect seal and turned the engine slow enough so as not to gain
> heat
> > by the compression you would see a compression pressure of CR x
> ATMospheric
> > pressure.
> >
> > However, it still is explained mathematically. Search for a reference on
> > Charles Law which states:
> > P1 x V1 P2 x V2
> > _______ = ________
> > T1 T2
> >
> > So if you know the compression Ratio and the temperature of the
compressed
> > air you can figure out what the compression pressure will is. Likewise
if
> > you can acurately measure the pressure you can figure out the
theoretical
> > temperature. If you come up with a temperature above 495 degrees you
will
> > have a Diesel motor running on Gasoline.
> >
> > I'm guessing that the 17 frogeye used in the example includes sea level
> > presuure of 14.7 PSI plus a generic fudge factor (or maybe it's a real
> > constant for 11.5:1, I don't know) to account for the increase in
> > temperature.
> >
> > All in all, I think it's pretty amazing that an ICE even runs at all.
> >
> > <dnw>
> > 1972 Midget
> > 1998 Safari
> > 1999 9-3
> > 1964 (Me)
> >
> > ----- Original Message -----
> > From: <John.Deikis@med.va.gov>
> > To: <spridgets@autox.team.net>
> > Sent: Friday, November 02, 2001 1:56 PM
> > Subject: Re: How Much Compression
> >
> >
> > > Unless I'm missing something here, aren't you confusing "compression
> > ratio"
> > > (a mathematical relationship of two volumes) with "compression
> pressure"?
> > >
> > > John Deikis
> > >
> > >
> > > >>Date: Thu, 1 Nov 2001 15:51:12 -0800 (PST)
> > > >>From: Ron Soave <soavero@yahoo.com>
> > > >>Subject: Re: How Much Compression Is Too Much?
> > >
> > > - --- frogeye <frogeye@swcp.com> wrote:
> > > > 11.5 x 17(or whatever atmospheric pressure is at
> > > > your locale) =195.5 It does
> > > > not compute. Check your gauge.
> > >
> > > >>Check the gauge, but again, CR x atmospheric pressure
> > > IS NOT WHAT YOU WILL SEE. Because the air is
> > > compressed in a constant volume, it heats up, tries to
> > > expand (but it can't), so the pressure in the cylinder
> > > increases, and the pressure read is much higher than
> > > CR x ATM. If heat were not lost through the metal in
> > > the engine, it would be way higher still.
> > >
> > > =====
> > > Ron Soave
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