High alt performance problem

[reflected]

I've been trying to figure out the secrets of full CEM and it's very frustrating, but exciting at the same time.

Now I think I got the hang of it, but there's something I can't understand. I can fly the 109 OK, my question is about Merlin engines.

So I manage the radiator to keep the temps below 120 C. I also reduce the RPM when I can, I fight at 2850, and only use 3000 RPM for very short times. I understand this is the only way to keep your oil temp low, isn't it?
I mean it's always at 95C, very hard to cool down.

At lower altitudes I do fine, however, when I go up to 14,000 feet or above, I can't seem to keep it low (oil). Up there I should be using 3,000 RPM according to the pilots notes, but it seems that I have to reduce the RPM to 2,300 otherwise my oil temp would go through the roof. With 3,000 RPM my engine dies almost immediately. Why is that?

Also, the mixture should be automatic, but up there I start losing power rather quickly. Maybe these two problems are related? Is there something I'm missing?

Thanks

PS: all this with head shake off, because if I turn it on my whole plane vibrates like crazy no matter what I do up there.

[Koala63]

CEM at altitude is broken. Pretty much everyone who has invested time into researching this aspect of the sim has come to the same conclusion AFAIK.

My current guess is that, in addition to the mixture settings, the turbo charger/blower modelling is also suspect. I set my personal altitude record this morning at 22,200ft for a hurri (DH prop) and above 20 thousand feet it was impossible to get a positive boost reading at all. It is like 2nd stage never kicks in.

Also, I find that I will always blow an engine with a fine pitch climb, even when I keep the rpm and temps well within limits. I can only keep my engine going if I change to coarse pitch before 7,000ft which is about where engine knock/vibration begins.

PS: all this with head shake off, because if I turn it on my whole plane vibrates like crazy no matter what I do up there Have you noticed that if you thottle back to idle, it glides smoothly and the vibration only returns when the throttle is increased again .

My fuel pressure gauge is also bust.

I think its important to be able to fly at historically accurate mission/patrol altitudes, and I'm not sure that this is feasible right now.

[Peril]

My current guess is that, in addition to the mixture settings, the turbo charger/blower modelling is also suspect. I set my personal altitude record this morning at 22,200ft for a hurri (DH prop) and above 20 thousand feet it was impossible to get a positive boost reading at all. It is like 2nd stage never kicks in.

The Merlin III only has a one stage blower ;)