ORIGINAL: JB COMP
Not trying to "burst your bobble" here, but from what I see in those pictures I can't believe that engine is still even running. You got kind of crazy on the cutting and probably started even having a negative affect on the engine.
FYI, timing is where the real power comes from. There's little to no power gains from "porting" an engine. Spend about an hour or two in the "nitro car engine" forum reading the post that come up when you search for "modding" and you'll learn a lot.
By the way cutting to much off the crank will cause the crank to vibrate more then before and will cause bearings to fail.
I am going to start by saying, that I am not a professional RC engine modifier. That is why I put these pitures on here to see what other modifiers think. However I am a professional ATV/Dirt bike engine modifier. That being said and you have seen the pictures, heres the theory behind what I did. Engine are all basically the same 2 stroke or four stroke, their basically air pumps, the more air/fuel they can take in and exhaust the faster they run. I agree that power gains can be seen from engine timing changes however it stands to reason that by opening up the crank, intake plus exhaust ports will allow more fuel air mixture into the engine and more exhaust to escape. I understand the point of the crank vibrating, but nitro engines do not have a counter balancing system in place. The perfect situation would be if the piston and connecting rod weighed exactly the same as the rotating bell on the crank then the piston and rod would act as a counter balancer for the engine. These are my thoughts curious to hear if anyone agrees. Thanks