And to get a bit further afield...

An excellent treatise on the entire issue can be found in Phillip K. Smith's
book "The Scientific Design of Intake and Exhaust Systems."  Or if one really
wants to read the definitive text, one can find a copy of Ricardo's "The High
Speed Internal Combustion Engine."  Written in the late teens - early twenties
and still the basis for ALL further research.

Jim Arnott
WetWesties List Admin.
Union, OR

Blue Eyes wrote:
>
> Mark wrote:
> "One thing often not considered on four stroke engines, the
> above it the
> way to figure uncorrected compression ratios. The proper
> 'corrected'
> compression ratio would take into consideration how late the
> valve closes
> as the piston is rising on compression. The longer duration
> the cam, the
> lower the corrected compression ratio."
> <snip>