Re: crossflow or looper?
Hello again,<br />You're off the mark a little. The crossflow has a piston design that has a very prominent raised section on top of the piston, this raised portion is very close to the intake ports. This raised portion causes the intake fuel mixture to hit it causing a swirling action back to the same side of the cylinder, and up toward the top of the cylinder, then back down the other side of the cylinder toward the exaust port pushing the spent exaust gasses out the port (and some fuel mixture). This is where the crossflow design ends.<br /><br />The loop charged design operates similar, but the design of the piston and ports are different. Loop charged pistons either have a flat, or domed top. these pistons have additional ports in the side as well as additional fuel slots in the sides of the cylinder. This design allows the fuel charge to be directed up toward the top center of the cylinder there it makes a looping action back down toward the exaust ports driving the exaust gasses ahead of it. Both of these designs only have to do with how the exaust gasses are scavenged from the cylinder, but at the exaust ports is where these designs end.<br /><br />Both of these designs are good, and have thier advantages, and disadvantages. Almost ever outboard makerhas used both at one time, or another.<br />Hope this helps you understand the differance.
