Radiator Question
 

Although I've played Il-2 for a bit, I've never actually assigned a joystock control to the radiator, because quite frankly, I don't know what impact it has. Maybe I should, but I haven't.

Now, seems to me that with 4.11.1, aircraft overheat with frequency and, I suppose, employing the radiator might, by goodness, be useful. So I have assigned a slider to it. Just can't figure out where to take it from there. So, some questions:

1. Does using the radiator, in fact, help prevent overheating?

2. Does using the radiator (assuming it helps cooling) have a negative impact on performance and, if so, how much?

3. I assume that by "opening up" the radiator, the higher percentage it's open, the greater the cooling effect, correct?

Any insight on this would be great.

PS: I've got a limited number of sliders, etc. on the joystick so assigning one to the radiator means removing another, so I'm trying to assess the pros and cons. It does not appear that you can operate the radiator with keystrokes.

Thanks.

You CAN operate the radiator with keystrokes. The command is named 'Cowl or Armor Flaps'.

Aviar

1. Yes, to certain degree.
2. Yes. Depends on the aircraft, but for a fighter about 20 km/h in speed and 1 m/s in climb.
3. Yes.

I have my radiators in IL2/46 set on a rocker switch on my throttle. It opens and closes the rads in 10% increments and selects the auto rad function on aircraft so equipped.

I use a slider in Cliffs of Dover, on the odd month that I actually fly it.

Hummm. Never noticed that before. Thanks.

When operating this function (letter "R" on the default keystrokes), as you press the keystroke the options are Closed, Postion 2 through 8, Open and "Closed/Auto". Closed and open are obvious, Postion 2 through 8 suggests incremental increases in opening the cowl, but what is "Closed/Auto"?

Some planes have a thermostat controlled radiator. If you use it, the radiator will be closed unless the engine is running hot, which is when the radiator opens automatically. Hence "closed/auto".

As far as performance impact, fully closed is maximum performance (speed) and fully open is minimum performance (speed). This, it turns out, is unrealistic, as most cooling systems had a design opening angle that was engineered for minimum drag, further closing was simply to reduce excessive cooling. It turned out, for instance, that the Fw190D's minimum drag setting was 23% open.

The game is what it is ...

Thanks all for your help.

One last question, however. Is it me or does the 4.11.1 patch seem to enhance overheating?

I strongly suggest you read the 4.11 Manual/Guide. There is an incredible amount of information there. As an example, here is portion from the Guide concerning the new overheat model:

Improved radiator & overheat modeling

4.11 introduces a more detailed and more accurate radiator model. It is different from the previous model in many ways, the main differences being:

• radiator settings now have an impact on both water/cylinder and oil temperature
• outside temperature now has an impact on oil temperatures
• engine rpm has a bigger impact
• impact of WEP is dependent on extra power generated
• mixture setting has an impact
• the density of the air has an impact
• aircraft speed has a bigger impact
• there is no longer a fixed period after which damage occurs in case of overheat
• introducing a random chance for damage depending on how strongly the engine
overheats
• type of damage is depending on if it is water/cylinder or oil overheating
You will generally find that the planes overheat a lot more, in particular if you are not on a cold map in fast level flight. As a guideline, on hotter maps you can expect fighters to be able to sustain about 70% power at 70% pitch without overheating radiators closed, for bombers it is somewhat more. The values in many cases are reasonably close to real life maximum continuous settings (please don't go by cockpit gauges, they aren't always accurate). If you start a low speed full power dogfight with a closed radiator, you can expect the engine to overheat rapidly and to get damaged quickly. War emergency power settings should therefore only be used in an emergency, otherwise your plane might get destroyed without your enemy even firing a shot.

To keep engine temperatures low, remember:

• use low rpm (reduce pitch), in particular oil temperature are sensitive towards rpm
• use low throttle settings (and avoid WEP)
• open the radiator
• fly faster (don't climb at too low speeds)
• use an as rich mixture as possible


Aviar

Yes, in addition to what Aviar has posted from the 4.11 readme my suggestion would be to do the following:

- Cruise at 70-80% throttle.
- Keep radiators at least partially open to maintain the engine at a reasonable level of cooling.
- Fully open the radiator during low speed dogfights or high angle climbs.
- Use the "prop pitch" control to lower RPM (this works on most fighters except the FW190, Bf109, and Spitfire IX... slightly different mechanisms there). I tend to run at 70% on during level cruise and anywhere between 70% and 100% during combat. I find 90-95% is a sweet spot with the most power for less heat.