X-Mozilla-Keys:                                                                                 
Paul Yaw wrote:

Another thing worth considering is the exhaust system/turbine  The
clearance volume is equal to about 11% of the total chamber volume on a
8.5:1 engine.  That means that at 100% VE, the intake charge is still
11% exhaust gas.  This will heat the charge BIG TIME.  Keeping the
exhaust backpressure as low as possible will do more to reduce the
likelyhood of detonation than anything else I know of.  If the engine is
bridge, or peripheral ported, the exhaust gasses in the clearance volume
can be replaced with fresh intake charge if there is a positive pressure
differential between the exhaust and intake during the overlap period.
This can be a bit touchy, as too much overlap, or too great a
differential will blow fresh charge right into the exhaust.  Either way,
the exhaust backpressure is critical.

PY

Unfortunately for this interesting discussion I am leaving for
the other parts. So hold those cards and letters folks.
And email messages!

Paul Lamar
 
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