How does the intake on the Weaver work?
This question and the next are closely tied. The Weaver belongs to a family known as “side-port” induction engines (or less frequently “three-port” engines). Side-ports use the piston to control the time and duration of the three basic internal combustion gas moving operations: intake, exhaust and transfer. This is done by arranging three openings in the cylinder that are uncovered by the piston top as it moves downwards (exhaust and transfer), and piston bottom as it moves upwards (intake). Because intake and exhaust/transfer are controlled by the piston, their durations are symmetrical around TDC and BDC respectively, hence side-ports will run equally well in either direction (and start backwards when you don’t want them to!) Consider what’s going on as this piston rises to Top Dead Center (TDC): since the crankcase is effectively closed, the increasing volume reduces the pressure inside, relative to atmospheric pressure. Just before TDC, the bottom of the piston skirt uncovers the i
This question and the next are closely tied. The Weaver belongs to a family known as “side-port” induction engines (or less frequently “three-port” engines). Side-ports use the piston to control the time and duration of the three basic internal combustion gas moving operations: intake, exhaust and transfer. This is done by arranging three openings in the cylinder that are uncovered by the piston top as it moves downwards (exhaust and transfer), and piston bottom as it moves upwards (intake). Because intake and exhaust/transfer are controlled by the piston, their durations are symmetrical around TDC and BDC respectively, hence side-ports will run equally well in either direction (and start backwards when you don’t want them to!) Consider what’s going on as this piston rises to Top Dead Center (TDC): since the crankcase is effectively closed, the increasing volume reduces the pressure inside, relative to atmospheric pressure. Just before TDC, the bottom of the piston skirt uncovers the i
