PDA

View Full Version : Question about overheat modelling



TinyTim
07-23-2008, 10:57 AM
If you overheat for too long, engine starts dying after some time from when "Engine overheat" message pops up.

Is this time the same regardles if you fly with rads open or closed?

Putting it differently: can you prolong the time before the engine damages by at least partially cooling it (but not enough for overheat message to dissapear).

zyotich
07-23-2008, 01:27 PM
Since no one is replying, I'll give it a shot. Yes, the rads are modeled in this sim. How well they work depends on what you are flying and at least a dozen other variables.
Lock yourself in your 'pit, watch your dials and take some notes, that's the only way you'll know what works for you--objective reality is pretty malleable in this sim and elsewhere in Kosmos.

ytareh
07-23-2008, 01:51 PM
Hi Tim I did quite a bit of research in this area in the game .

EDIT Tim heres the exerpt which answers your questions in case yer in a hurry!

"The speed you fly at WHEN OVERHEATING doesnt matter .But it does when cooling down.

It doesnt matter whether your rads are open or closed when actually overheating"


FULL OVERHEATING REPORT

"I tested the time from when the OVERHEAT message first appeared to when the engines first made that harsh screeching sound to when they would totally stop with ENGINE INOPERABLE message

I tested A6M2,P51 D20,109G2,P47D27LATE,190D944,Tempest,Ju88,Spit 25lb,Spit Vb,Ki27,La5FN and Mosquito.

I used the X8 speed up function to quicken the procedure where possible.

I used the Crimea Quick Mission Generator map /Axis 1000m start altitude.



With few exceptions which I will mention later ALL PLANES HAVE THE EXACT SAME OVERHEAT MODEL
Namely :

WEP/Boost/110% etc .Rads Shut.approx 5minutes 10seconds to 'harsh noise' and 6minutes 10 seconds to total engine failure

This is not affected by whether you are travelling at very high or low speeds

The 'harsh screeching noise' seems to result in performance being reduced to about 80% and max altitude reduced .


EXCEPTIONS /PLANE NOTES

A6M2: Makes screeching noise after about 5 and a half minutes and then ENGINE NEVER STOPS


P51D20/Bf109G2/190D9 44/Tempest/Ju88/Spit Vb/La5FN/Mosquito: All follow model described already for WEP /Boost/110% rads shut.

P47D 27 LATE: 10 and a half minutes to screeching and 11 and a half minutes to engine inoperable.

Spit 25lb : OVERHEAT MESSAGE APPEARS BUT ABSOLUTELY NOTHING HAPPENS EVER!!!!!

Ki27 : Gradual increase in engine whine/screech from about 4 minutes but engine never becomes inoperable whether rads are open or closed

ytareh
07-23-2008, 01:54 PM
More !( Hey just had my 1600th post !Phew!)

"FURTHER NOTES :



190D9 44 Indepth Study :

No Boost, 110%, Rads Shut-EXACT SAME OVERHEAT TIME/BEHAVIOUR AS WITH BOOST ON

Boost On,110% ,Rads Open- Same time to screeching BUT ENGINE NEVER BECOMES INOPERABLE

Boost Off ,110% ,Rads Open-Same time to screeching BUT ENGINE NEVER BECOMES INOPERABLE AND BOOST CAN BE REENGAGED AFTER THIS POINT AND RADS CLOSED BUT ENGINE REMAINS 'IMMORTAL'

Cooling in 190D9 44 in fast descent Vs slow climb (at 4-5k alt approx)
-After 60 secs overheating with boost/110% /rads shut the rads were opened and throttle taken back to 95% -it took 36 seconds to cool back down (overheat message off) in a steep dive reaching 800kmh-it took 61 seconds to cool down in a slow climb 210kmh approx.



La5FN: At 99%, rads closed the plane could be flown level indefinitely at low alt .Slow climbs did cause an OVERHEAT message to briefly appear AND THEN DISAPPEAR for good

Ju88 :102% Rads Shut EXACT SAME BEHAVIOUR AS 110% RADS SHUT
100% Rads Shut NEVER OVERHEATS (at least in level flight)



CONCLUSIONS FOR IL2 PILOTS -Most Planes Engines Start to Seriously Overheat 5min 10 sec after overheat warning-Dead At 6min 10 sec

The speed you fly at WHEN OVERHEATING doesnt matter .But it does when cooling down.

It doesnt matter whether your rads are open or closed when actually overheating

If you absolutely have to keep flying eg on long missions over enemy territory you will never loose all engine power if keep rads open in 190D9 44 and Spit Vb (perhaps other planes)and even with them shut in Zero.


La5FN and Spit 25lbs are UFOs!No seriously, apparently late Spits didnt overheat even in 'real life'.(Had massive rads!)

ytareh
07-23-2008, 01:57 PM
ALSO :

"Many/most planes are (10kmh)faster at 110% and rads open than 100% rads shut .Tested informally with fighters and more carefully with level stabiliser with bombers...."

na85
07-23-2008, 03:06 PM
Does the radiator setting affect the time between "screeching" and engine failure on the common block of planes?

chunkydora
07-23-2008, 03:07 PM
Thanks for the tips, ytareh!

ytareh
07-23-2008, 03:14 PM
na85 once you are actually seeing the overheat message it makes no difference whether you have rads open or closed it takes roughly 5min 10 secs (but more than DOUBLE that in P47) to engine failure.There is some pretty strange rad /overheat modelling in the game but I suppose youd need a MONSTER PC to get all the modelling right...
Apparently in real life if you went into a power max speed dive from overheating you could blow your engine (like pouring cold water into an overheating car engine )

ElAurens
07-23-2008, 04:55 PM
The overheat model for all piston aircraft is wildly exaggerated in the sim.

In every pilot's operating manual I've read for warbirds there are numerous references to the danger of over cooling the engine, but almost none about overheating, except during ground movements.

WTE_Galway
07-23-2008, 05:21 PM
Originally posted by ElAurens:
The overheat model for all piston aircraft is wildly exaggerated in the sim.

In every pilot's operating manual I've read for warbirds there are numerous references to the danger of over cooling the engine, but almost none about overheating, except during ground movements.

RAAF Spitfires based in Northern Australia had a lot of overheating problems. As far as I know they were tropicalised mk V's.

Darwin gets pretty hot by anyones standards though.



In terms of the original topic. Interesting testing ytareh. Did you check how long you need to be back on normal before you get another 6 minutes of overheat? My impression is if you can get the temp back to "normal" for even a few seconds you get another full 6 minutes or so overheat time before damage.

DKoor
07-23-2008, 05:41 PM
Originally posted by WTE_Galway:
My impression is if you can get the temp back to "normal" for even a few seconds you get another full 6 minutes or so overheat time before damage. If you manage to cool engine for a fragment of a second in game overheat time counter resets and you have full original overheat time at your disposal again.

Spitfire25 is a fine example of that... run full speed at deck, after some time it says engine: overheat!, but every few seconds message disappears and reappears in a blink of an eye and counter is reset (you don't have to change anything - just run straight @ full power @ deck all the time), so Spitfire runs that way until out of fuel.

TinyTim
07-23-2008, 07:49 PM
Thank you for all the info, testing and effort, appreciated ytareh. http://forums.ubi.com/images/smilies/25.gif

So, an overheat message is like a ticking bomb which you can't slow down, you can only reset it by making the overheat message dissapear. Hell might even place a stopwatch by the monitor http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif.

Do you know if the very long duration before damage, which P-47 "sports", is there also on other R-2800 powered planes, like Corsair or Hellcat (can't think of any more from the sim having it)... They share a radiator bug with P-47, maybe also this prolonged time "feature". BTW, interestingly radiator bug also affects the J2M3/5.

tragentsmith
07-24-2008, 05:19 AM
I can add one more thing. If you fly over 600 kph whatever the bird, you won't overheat anymore. The easiest test is with juet, but counts also for all other planes.

Bremspropeller
07-24-2008, 05:30 AM
Originally posted by ElAurens:
The overheat model for all piston aircraft is wildly exaggerated in the sim.

In every pilot's operating manual I've read for warbirds there are numerous references to the danger of over cooling the engine, but almost none about overheating, except during ground movements.

+1