A piston is at bottom dead center when it is()
A、opening the exhaust ports
B、closing the fuel ports
C、farthest from the cylinder head
D、nearest to the cylinder head
A、opening the exhaust ports
B、closing the fuel ports
C、farthest from the cylinder head
D、nearest to the cylinder head
A、top of the piston and bottom side of head, with the piston at BDC B、piston and head, including the space around the piston to the top of the upper ring and under the valves, with the piston at TDC C、bottom of the piston and bottom side of the head at TDC, regardless of upper ring location and valve placement D、top of the piston and bottom side of the head at TDC as compared to that which exists between the top of the piston and bottom side of head at BDC
A、A.facilitate the installation of piston rings B、B.allow for the expansion of the piston during operation C、C.prevent crankcase vapors from entering the combustion chamber D、D.reduce wearing of the upper cylinder liner
A、reciprocating at the piston pin, rotary at the crank pin B、reciprocating at the crank pin, rotary at the piston pin C、straight reciprocation D、straight rotation
A、Because the piston is exposed to very high temperature, it must be cooled B、The lower the piston cooling temperature is, the better it is C、Both water and lube oil can be used as coolant D、One of the piston cooling methods is vibration cooling, with better effect
A、atop the piston crown B、beneath the piston crown C、at the base of the piston skirt D、inside the cylinder liner cooling water jacket
A、radially from the shaft B、parallel to each other and to the shaft C、parallel to each other but at a right angle to the shaft D、at an angle to each other and to the shaft