Engines
 

Waht is the difference between a Ringed Engine and a Non Ringed Engine ?

Which one is better & why ?

thanks

Engines
 

ringed engines have a small compression ring installed around the piston that seals it against the sleeve. similar to a weedwhacker or a car engine for example.

ABC engines have sleeves made of Aluminum, Brass, and Chrome.. and usually the piston is made of silicate aluminum. these rely on very close tolerances between the piston and sleeve in order to acheive a tight piston fit.

they both have advantages and disadvantages:

RINGS:
advantages:
more tolerant to harsher running conditions (dirt/sand runways.. dusty conditions..etc)
better wear tolerance
economical to refit when the piston/sleeve fit (finally) wears
more tolerant to running hot
less "finicky" than ABC, AAC, ABN etc


disadvantages:
piston/sleeve fit most efficient at certain temps
piston/sleeve fit not as close as ABC
longer break-in period

ABC (AAC, ABN, AAN..etc):
advantages:
piston/sleeve fit relatively independant of temp
closer piston/sleeve fit with less compression leak which leads to-
more power
compression stays relatively the same independant of temp
short break-in

disadvantages:
less tolerant to harsh running conditions
less tolerant to lean running
costly to repair once sleeve and piston wear
tend to be "finicky" when compared to rings
one grain of dirt can distroy the piston and sleeve.