Moki S 215 / 250 Radial 5 Cylinder Engine Baffle Plate
You will not find a full size radial powered airplane of the cowl'ed kind that is missing baffles. Air is lazy and will find the path of least resistance, meaning it will go everywhere but where it is needed: between the fins of your motor.
Furthermore we need to somehow achieve a positive ratio of incoming to exiting parting. Meaning, your round opening of you cowl is most if not all cases exceeds the exit port by a multiple, creating a bottleneck design which hinders all heat management.
The CAD designed and CNC cut baffles not only guarantee that your incoming port (surface area) is now as small as can be and therefore you create a rapid exit airflow inside your cowl, we are forcing the air to travel through the fins at an accelerated speed.
When installing: Make sure that neither the hall sensor cable nor the impulse line (tubing, should it be in place and be used) is being pinched by or rubs on the baffle.