HI!
WHICH IS THE DIFFERENCE BETWEEN THE GEOMETRIC AND THE EFFECTIVE COMPRESSION RATIO???

THANKS

Geometric compression ratio are measured volume between TDC and BDC + volume of compression camber.

Effective compression ratio are measured volume between TDC and from the exhaustport are closed (twostroke engine) or intake valve (4 stroke engine) are closed + volume of compression camber.

See the link: http://www.modelenginenews.org/faq/index.html#qa13