Are Stages 2-3 and 1-4 in the OTTO Cycle Adiabatic?

[JakePearson]

hey guys, just wanted to know, in the graph of the OTTO cycle in the link

http://www.qrg.northwestern.edu/ther...Pv-diagram.gif

are stage (2-3) and (1-4) adiabatic or not, if so why are they

the reason i ask is that i have a graph showing that these stages are adiabatic, however, adiabatic processes are where no heat is exchanged QIN = 0

 

[Redbelly98]

Your image link is not working.

 

[xxChrisxx]

In the ideal otto cycle

The expansion and compression are isentropic (reversible adiabatic).
The heat addition and heat rejection are isochoric (constant volume processs)