Analysis only valid if cores are identical in construction (resistance
to air flow will likely be different with the different cores).

Charlie,

Good point. We do have a known relationship of how the cores behave
using the temps before and after the exit area was enlarged.

My notes show oil at 220-225 and water steady at 190 before enlarging.
Mark reported oil at 215 climb and 190 cruise and water at 160 (cruise?)
after enlarging.

Exit area improvements. 95-95 deg OAT if my notes are correct.

Oil 225 -215= 10 climb
Oil 220-190 = 30 cruise

Water 190 - ? = ? Climb (no data)
Water 190-160= 30 cruise.

It is clear that enlarging the exit area is made improvements to both
oil and water cooling.

Bobby (hope I never need to understand the other 80% of the equation)