RE: Cox .074
The QB I bought had a straight cylinder. There was zero compression with it, very disappointed.
It is now polished and sitting with the collection, or used for an occasional paperweight.
It looks like a Cox, but never did run like one.
I want to maybe convert it to an .09 cylinder and use it in a boat. The rear intake fits right in to what normal boat engines are like.
With a turned-around muffler it would work good to route an exhaust tube out the side to keep the engine bay somewhat clean, and it having somewhat of a normal RC carb is nice. Just wish it had more power. They are heavy for their size.
The QB has the LOOKS to be a real powerhouse the way it is designed, but it just don't have the poop. It's too bad.