According to the box ( and I hope it's the correct box), it is a 26600 Fox Eagle "60" BB Ring Schnuerle....is that the Eagle 4?? It has the two needle carb. When I originally got this engine (along with a bunch of other rc stuff), it was in a box that read Fox rear exhaust, and I thought that's what it was, since the exhaust was facing the rear.Then I noticed that the cooling fins were not runnng parallel with the airflow. I'm guessing that someone turned the cylinder on a standard Fox side exhaust. I turned it back to the original side exhaust, and decided to sell it. I figured i'd better test-run it, just to be sure. It sounded like it was turning some pretty good rpms, so I decided to get the tach....sure enough 11500-11700 with a master airscrew 12x8....I figured I had a "keeper". And now you know "the rest of the story"