He is talking about the CV not the CV-R big difference. The CV has the square head and the CV-R has the round head. The CV is very reliable but is very low on HP. I agree co with the .18 CV-R or the CV-RX. The X stands for pull starter. If you want all the HP you can get in a small block go with the TZ. But it is coast twice as much but is one heck of a engine. OS makes great engines!