3-ring autothermic pistons

[tumleweed]

Are the 3-ring autothermic pistons the ones to use or is there a more user friendly piston. I'm not trying to recreate anything special, just want it to be reliable.

 

[Dell (WA)]

weedie........use the 3-ring pistons. The original 4-ring pistons turned the N-Engine into an oil-burner. Most people don't realize the top compression rings are "sealed" in oil for maximum compression. The bottom "4th" ring scrapped the oil off'n the sleeve before it gotta chance to seal the compression rings. Autothermic piston describes the way it is built to control expansion/wear. .......Dell