I am actually surprised more people are not taking a serious look at his new cylinders, (ACE-Performance) Don't QUOTE me, but with my hot rod building experience, we always looked for externally and internally induced turbulence in the combustion chamber, my observations of these new AX50 cylinders, they have a quench area on opposing sides of the head, (I am guessing for the above reasons) allowing higher compression and lower octane fuel of similar designs. ACE is calming up to 220 HP out of their 379! and the ability to run auto fuel, and I think he also mentioned using synthetic oil. I'm sure someone will chime in to correct me if any of this is inacurate, but I am sold on this engine!