Spark Advance Engine POWER!

[Tony Bryant]

> 
> I've been doing a little light reading (always dangerous) on Internal
> Combustion, Spark Ignition Engines.  I have discovered that, theoretically,
> for peak power and fuel economy, the spark should be advanced (degrees
> BTDC) as far as possible until the engine begins to knock, then of course
> backed off a little- you don't want it knocking.  Also, for peak power and
<SNIP>

This is not necessarily true. It is possible to over advance without 
causing knock (on low compression engines on high octane). What 
happens then is that the rapidly expanding gases are doing more work 
against the rising piston BTDC than ATDC (when the work does 
something useful).
 
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* "Insanity is the only sane response to an insane world" *
*                 >> bryantt at fp.co.nz <<                  *
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