Matt. What Neil, Bobby & Charlie said.  I am making all the mistakes, I have same oil cooler and now repositioning to face it onto airflow, I find low speed, high power & summer heat is challenging, but need to get through this to get to cruise height & power, so design for worst airflow your plane will see, admittedly, my inlet is closer to prop hub and does not see enough prop blast for real good ground testing at very high power. So all my high power tests have been flying circuits, some at very low level. disconcerting if a change that should improve cooling in theory has the opposite effect.