The divided combustion chambers of a two-liter, four-cylinder, lean-burn, stratified charge SI engine have 22% of clearance volume in the secondary chamber of each cylinder. The intake system delivers...

The divided combustion chambers of a two-liter, four-cylinder, lean-burn, stratified charge SI engine have 22% of clearance volume in the secondary chamber of each cylinder. The intake system delivers an air–gasoline mixture into the secondary chamber at an equivalence ratio of 1.2 and into the main chamber at an equivalence ratio of 0.75.

Calculate:

(a) Overall air–fuel ratio.

(b) Overall equivalence ratio.