Re: loop motor
It referrs to the way that the fuel and air charge is forced into the cylinders. With loop charging, it comes in through aimed ports and swirles as it scavenges the burned gasses out.
The other type is cross-flow, where the charge comes straight in and hits a deflector on the piston top, which sends it to the top of the cylinder and scavenges the burned gasses out the other side.
In addition to free flow of the air, the looper has much lighter pistons and thue less recriprocating weight. Just plain more efficient. Almost all chainsaws are loop charged. You probably have heard how they rev without self destructing.
