Type 4 mechanical compression ratio, Why is the factory compression so low? Options

[Beebo Kanelle]

OK, here's a fun one for the novice to ponder and you experts to answer:

Why is the factory mechanical CR so low?

and for reference, what is the highest mechanical CR that can be physically achieved? assume no octane limitations -

I'm just looking for the design limit for the highest CR that can be / has been in a Type 4 engine using available technology.

Thanks

[McMark]

If you're looking to improve thermodynamic efficiency, why are we talking about compression? Why are we talking about horsepower? Neither of things have any direct connection to head cooling.

You're being very cagey about what you're actually trying to do. It makes it hard to help.

[ra272]

If you're looking to improve thermodynamic efficiency, why are we talking about compression? Why are we talking about horsepower? Neither of things have any direct connection to head cooling.

You're being very cagey about what you're actually trying to do. It makes it hard to help.

The raise in power from higher cr comes from a better thermodynamic efficiency. If you would measure the exhaust gas temperature the higher cr engine will have a lower exhaust gas temperature. That is we're the extra power comes from. I guess lower exhaust gas temperatures will also affect cilinder head temperature, especially in an air cooled engine.

[Mark Henry]

If you're looking to improve thermodynamic efficiency, why are we talking about compression? Why are we talking about horsepower? Neither of things have any direct connection to head cooling.

You're being very cagey about what you're actually trying to do. It makes it hard to help.

The raise in power from higher cr comes from a better thermodynamic efficiency. If you would measure the exhaust gas temperature the higher cr engine will have a lower exhaust gas temperature. That is we're the extra power comes from. I guess lower exhaust gas temperatures will also affect cilinder head temperature, especially in an air cooled engine.

HA-HA McMark....it wasn't me! (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/happy11.gif) (IMG:style_emoticons/default/smile.gif)

Oh wait.... now it is ....Doh (IMG:style_emoticons/default/slap.gif)

(IMG:style_emoticons/default/screwy.gif)

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