IL-2 1946: help needed about radiator, overheating, power and props

[Loud_Silence]

I get headaches thinking about power and propeller settings, and I don't know what are the best general rules when using them. This is what I know.

If the radiator is fully closed and the engine is working at 100%, it will overheat, but if the radiator is fully opened, it won't. And at 110% the engine will overheat no matter how the radiator is set, right? Does WEP/Water Injection/MW50... help with this?

Is 100% power and prop the only way to reach top speed at level flight? I know that having the radiator fully opened can slow down the plane a lot. Is something like position 4 or 6 enough to cool the engine at high speeds?
And at top speed or during high speed dives, it's better to leave the prop at 100% or reduce it? And how much?

For cruising, I use a combination of 80% power, 80% prop and radiator fully closed.

[Oberon]

The others will be better at answering this, but this is how I generally operate.

Stick radiators open until in a combat zone, particularly if there's flak around, slam them shut then otherwise stray metal gets into your engine and it's generally bad. Plus you will need the extra power. If you overheat, throttle back until it cools (or if you want to exploit IL2, just put the throttle back, wait until it goes to 'Normal' and then open it again...it will on many planes reset the countdown until engine damage, in reality it wouldn't.) You can go quite a few minutes on 'overheat' before the engine starts being damaged, but generally if you overheat you'll just have to throttle back a bit. If you happen to be chasing someone and you're sure your six is clear, you can probably open the radiator a bit, but if you're on high revs it probably won't do anything anyway, but just beware of flying bits of metal.
In regards to prop settings, I've found that if I'm up about 2000m or so in a 109 then slapping pitch to about 80-95 will give me a bit of a boost. It's a bit like the reverser in a locomotive, put it back too much and you'll run out of steam, leave it too far forward and you'll be making more work for the engine for less gain. There's probably a table for what pitch to use at what altitude, Schroeder probably has it, but I generally don't go lower than 70.
Another thing which will affect your power on some aircraft is the supercharger, after you climb above a certain altitude remember to switch to Supercharger stage two or you'll lose some power, likewise when descending remember to switch back to stage one.
WEP...that can increase your speed but will also increase the chance of overheat. It varies in aircraft but in reality most aircraft would screw their engines up if WEP was left on for too long, although in the BOB pilots did make liberal usage of it to catch up on 109s, but generally there was a reason that you had to break a wire to push it fully forward on a Spit and that was because it was bad for the engine if overused.
Your cruising ratio sounds similar to what we use, although often we put radiators open.

So, basically, yes the engine will overheat at 110% there are factors which affect that, but WEP is not one of them I believe. Speed is one, I think, possibly altitude as well, not sure about that. The other guys will have more knowledge, but I have found that how long it takes the engine to overheat at 110% does vary in different situations and also in different climates. You can probably push a 109 for longer over Russia than you can over Tobruk (unless you have the trop version which would last a bit longer), I'm not 100% sure that's modeled in IL2...but it certainly does feel like it, the amount of times I've overheated whilst flying over the desert.

[Schroeder]

Well, in a German fighter I don't care for the prop pitch or supercharger settings as those are regulated automatically by them. In a plane with constant speed propeller (this means that you actually set a certain amount of RPMs and the prop will always adjust it's pitch to keep the engine running at that RPM level) I go for 100% pitch on take off and in combat and 60-70% at cruising. Theoretically you can let the engine rev at it's max all the time, Il2 doesn't punish you for this but it's unrealistic and the engine is pretty loud and annoying that way. I usually switch the charger at around 2800 - 3500m altitude depending on the plane (and whether I remember to switch).
I never overheat my engines for more than mere seconds. The moment the "Engine Overheat" message pops up I lower my throttle. Some engines really don't like overheating!!! Also be careful with the emergency power. Some planes have special WEP systems that can only be engaged above a certain altitude (some 109 versions have that, I forgot which though). If you engage it below that altitude your engine is done for (nasty to learn that the hard way in combat)!

In level flight you can use a radiator position of 2 to prevent overheating, but as I said earlier I always keep them open to the max to keep the engine as cool as possible before entering combat. In a dive you can reduce the pitch to slow down the engine (I usually take 70%) this will give you extra speed since a low revving propeller offers less wind resistance than a fast revving one (be careful not to exceed the limits of your aircraft, reduce throttle and start to pull out gently the very moment your aircraft begins to shake from the speed or you'll probably end up losing control surfaces and eventually wings ).

[Raptor1]

Originally Posted by Schroeder

Theoretically you can let the engine rev at it's max all the time, Il2 doesn't punish you for this but it's unrealistic and the engine is pretty loud and annoying that way.

Not since 4.10, now your engine has a (Higher) chance of failing if your run it on full power too much. That's what the 'Reliability' setting in the realism is for.

[Schroeder]

Ah, finally.

[Loud_Silence]

Hm.... it makes sense to close the radiator when there's shrapnel flying around.

I made an experiment with the Hellcat and opening the radiator didn't slow me down... I could swear that once, after opening the radiator I slowed down some good 30mph...

[Schroeder]

The radiators don't slow you down that much actually. It's hardly noticeable (at least to me).