Digger
Serious Thumper 2005 No Login
Offline
Ya gotta be tough to ride singles!
Posts: 1604
Colorado Springs, CO
Gender:
|
Yep, to put it in agricultural terms, a four stroke engine goes:
Suck, Squeeze, Bang, Blow, Suck, Squeeze, Bang, Blow, Suck, Squeeze, Bang, Blow.....
The crank must rotate twice (or, 720 degrees) to make it through each set of the four phases (note that these four phases comprise a single full cycle).
At the beginning of the Suck (intake) phase, the piston is at TDC. This position is generally referred to as "TDC on the exhaust stroke" as the exhaust ("Blow") phase is just ending (see below).
The piston moves down until it gets to bottom dead center (BDC). Here is where the Suck phase ends and the Squeeze (compression) phase begins.
Then, the piston moves back up until it gets to TDC again (completing one of the two full turns that the crank needs to go through to complete one cycle). This position is generally referred to as "TDC on the compression stroke" as the compression ("Squeeze") phase is just ending. This is the TDC you need to achieve before taking the head cover off and before putting it back on.
Next, the piston moves back down again, during the Bang (power) phase,until it again gets to BDC.
Finally, the piston rises again during the Blow (exhaust) phase, heading back toward TDC on the exhaust stroke. When said TDC is reached (thus completing two full crank turns and, therefore, one cycle), the piston moves back down again on the Suck phase and starts the whole 4-cycle thing over again.
Clear as mud?
|