Compression Ratio?

["Fred Wills" <Fred.Wills@xxxxxxxxxxxx>]

<<Date: Mon, 18 Feb 2002 09:04:14 -0600
From: Mark Johnson <mjohnlit@domain.elided>
Subject: Increased Compression?

I don9t know where JK took physics, but think about it...

Yeah, if there is carbon (or a dome, or a melted top of a spark plug did
that once or whatever on a piston it decreases the chamber volume.
However, the chamber volume is increased on the intake stroke, as well as
the compression stroke.  Assuming the intake pressure is at one atmosphere,
the compression ratio would be the same with or without the reduced volume.>>

Actually, yes Mark, you are missing something.  Any decrease in volume of the
combustion chamber will represent a larger percent of the total volume at TDC
than at BDC and will therefore increase the compression ratio accordingly.
But that's doesn't mean that an increase in compression ratio is always a good
thing.


Fred Wills
Londonderry, NH


- ---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.313 / Virus Database: 174 - Release Date: 1/3/2002

------------------------------