Help! Keep blowing the engine.

[NedLynch]

If I may I would have two questions regarding boost and radiator position.

Do I understand it correctly that boost can only be influenced "indirectly" by adjusting throttle and prop pitch (WEP excluded) ?

In combat would it be advisable to leave the radiator(s) fully open or does that cause too much drag and will give you a significant disadvantage, enough of a disadvantage to close them fully or to a degree and live with the risk of blowing your engine/overheating your engine?

I finally did manage to get my Me 109 in free flight to run cool enough ( no more oil on the cockpit window, looks cool though ) but I tend to leave the water radiator fully open and the oil radiator maybe 1/4 open with throttle set to 75% or a little less and playing around with the prop pitch.

It is quite amazing how much speed you can actually get with a trimmed aircraft and the right prop pitch-playing-around (yes that is the professional nomenclature for the procedure) at a rather low throttle setting.