O/T Compression ratio and supercharging

[Todd....!!]

Moving the cam timing around(i.e. retarding or advancing the cam(s))
will also change both the static and dynamic compression ratio...

LATER,

Todd....!!

Don.F.Broadus at ucm.com wrote:
> 
> You are correct, The mechanical compression ratio can be 10:1 but when you
> check it with a gauge the effective compression ratio
> pressure will  be on par with a 9:1 engine. Mechanical compression gives you
> efficiency while effective compression ratio that is controlled by valve
> timing gives you knock control and good combustion.
> 
> > -----Original Message-----
> > From: Shannen Durphey [SMTP:shannen at grolen.com]
> > Sent: Wednesday, May 26, 1999 12:55 PM
> > To:   diy_efi at efi332.eng.ohio-state.edu
> > Subject:      Re: O/T Compression ratio and supercharging
> >
> > Todd....!! wrote:
> >
> > > Another tidbit that may or may not help is that my 91 Mitsu Eclipse
> > > Turbo 5-speed had only 120 lbs. of compression pressure on all four
> > > sylinders....
> > >
> > I believe that cranking compression ratio has more relation to stroke
> > length and valve timing than compression ratio.  Anyone?
> > Shannen