LOOP CHARGED ?

[C-RAVEN]

Pardon my ignorance, but what is the difference between loop and crossfire ignition in a 2 stroke outboard ?<br /><br />just curious

 

[JB]

Re: LOOP CHARGED ?

Cross scavenged engines use a deflector on the piston to direct incoming mixture up to scavenge the cylinder, where it crosses to the exhaust ports. <br /><br />Loop scavenged engines use a flat top piston and direst the incoming mixture away from the exhaust ports, requiring it to loop over the top of the cylinder to scavenge the cylinder.<br /><br />Loop scavenging is far more efficient, allowing more power and efficiency from the engine.<br /><br />Use the search function to search for more detail and diagrams of loopers vs. cross scavenged engines.<br /><br />Good luck.

 

[Orlando Len]

Re: LOOP CHARGED ?

A loop charged engine refers to the method the fuel introduced into the cylinder. The fuel is directed into the cylinder in such a way <br />(porting) that it pushes the remaining exhaust fumes out of the combustion chamber with out the aid of a crowned piston . In a loop charged engine the piston is flat on top, unlike a typical 2 stroke piston that has a tall crown. The main advantages are, the downward force of the expanding hot gasses during combustion are not deflected towards the cylinder walls but instead push squarely on to the piston. A compairable piston also weighs less in a looper.