you find the barometric pressure and convert it to psi
760 mm Hg = 14.696 psi = 760 Torr = 1 ATM = 29.921 in Hg = 1.01325 bar =
33.9 feet water .....
the reading given on the weather channel is in inches mercury
29.921 inches mercury = 14.696 psi
barometric pressure is the pressure when the piston is all the way down.
when it is at the top it is that number times the compression ratio
ie. if the atmospheric pressure is 29.921 inches then it is 14.696 psi
if the ratio is 10:1, the compression should be at most 146.96 psi
----------
> From: Robert Lee Cobb Jr. <S0042745@cedarnet.cedarville.edu>
> To: dakota@ait.fredonia.edu
> Subject: Re: COMPRESSION TEST -Reply
> Date: Tuesday, February 18, 1997 11:33 PM
>
> >Correct, the book listed it at 9.1:1 with the cylinder head pressure
> > at 100psi, gasket thickness at 0.0475, but my combustion chamber
> > worked out to be 9.375 after doing the math.
> > Kuk
>
> Kuk, what do I use to figure out my compression ratio? I checked the
> compression about 10k ago and I got between 145-155 psi on the
> cylinders. From what you guys are talking about, that's stinkin'
> high. What kind of CR does that yield? What formula do you use for
> computing it? Everything as far as the heads, pistons, gaskets, etc.
> are nothing but stock. What's going on with my high CR?
>
> - Rob Cobb (93 V8 LE 2wd). . .
>
> P.S. I FINALLY have the homemade traction bar pictures. . .I still
> have to get them scanned in and a diagram drawn up with the
> dimensions on the pieces, though. BUT, I'm trying. . .
>
>
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:07:32 EDT