how to get the most out of the stang?

[Merlin-27]

...there people keep talking about leaving the rad settings on either auto or manually...this confuses me a bit, and i dont know if i understand the system, or better the cockpit switches correctly...

right now im away from home so i cannot check it myself for now, so correct me if im wrong, but for both the water and the oil radiator there is this three position switch...auto-close-open and both are set by default to auto.you can manually push and hold them either in the close or open postion...as long as you hold the switch, it will either close or open the rad, and once you release the switch, it will automatically switch back to auto postion...so when it tilts back to auto postion, is it then controlled again by the automatic system?or will the radiators stay in the position where i left them?how do i switch to automatic position again?

i think there is an error somewhere in the above paragraph, but thats my understanding of it so far...and im confused, but im sure somebody can enlighten me. :)

 

David,

I think I understand your one specific question as I had been battling seized engines for a while. From my experience, I test this theory on a daily basis, you can open the coolant radiator with the momentary switch held to open (takes 20-25) seconds to open completely. Once you release the switch it will move to the middle position which is OFF. The switch cover will remain open. If you click on the switch cover it will close and move that switch up into the AUTO position.

 

So I myself, and this has definitely helped me so far, immediately open the coolant radiator doors/flaps fully open on start up. (You can confirm its operation with external view) They will not close unless you hold the switch to CLOSE or like I stated above, close the switch cover.

 

Hopefully we can get an official confirmation on this as well.

[The LT]

David,

I think I understand your one specific question as I had been battling seized engines for a while.

 

After getting a firm grasp on the engine operating ranges and having followed Yo-Yo's guidelines on engine operation, I didn't have a seized engine in more than 20 hours of flight time, in the whole range of operating modes, including WEP bursts.

 

Most of the time my rads are set to automatic, for low speed, I might open them up, but 90% of the time they are on auto. No problems.

 

It might be worthwhile to analyze your actions and see where the fatigue builds up...

[Yo-Yo]

No, I mean open :thumbup: Just noting to David that the Mustang coller design was different and very specific, and some of the rad flap drag is cancelled by Meredith effect. So you don't have your usual linear case of radiator more open = more drag. Just as you stated, it gets even more complicated with the aftercooler etc.

 

We must put apart the radiator drag and the effect of radiator to the propulsion power of the engine/prop.

Radiator drag itself increases as the scoop is being opened.

Meredith effect was not a secret since jet-engine theory became very common.

Any correctly designed radiator installation has a ram expanding to the radiator to reduce air velocity through it. When the air passes through the radiator it loses part of its pressure (and this is drag source!) but gains heat. Then heated air goes to the outlet that can be diverged or converged. It's a kind of jet nozzle, but it produces thrust ONLY if it is converged (subsonic nozzle, not Lavalle). As it is converged it plays several roles - decreases the amount of the air that decreases drag, increases the air teperature and accelerates the air as a converged nozzle producing thrust.

 

I must emphasize that only two factors can produce THRUST - significant heat input and converged nozzle.

[Merlin-27]

After getting a firm grasp on the engine operating ranges and having followed Yo-Yo's guidelines on engine operation, I didn't have a seized engine in more than 20 hours of flight time, in the whole range of operating modes, including WEP bursts.

 

Most of the time my rads are set to automatic, for low speed, I might open them up, but 90% of the time they are on auto. No problems.

 

It might be worthwhile to analyze your actions and see where the fatigue builds up...

 

THIS is exactly why I was careful in saying "your one specific question" in my reply. I provided information on the operation of the switch. Not cooling techniques. I applaud you on your 20+ hours of perfect engine management. I myself am still learning this delicate dance (Manifold vs. RPM) and I also have been using Yo-Yo's advice (among others) on operating methods, which have provided much greater success.

[Robo.]

We must put apart the radiator drag and the effect of radiator to the propulsion power of the engine/prop.

Radiator drag itself increases as the scoop is being opened.

Meredith effect was not a secret since jet-engine theory became very common.

Any correctly designed radiator installation has a ram expanding to the radiator to reduce air velocity through it. When the air passes through the radiator it loses part of its pressure (and this is drag source!) but gains heat. Then heated air goes to the outlet that can be diverged or converged. It's a kind of jet nozzle, but it produces thrust ONLY if it is converged (subsonic nozzle, not Lavalle). As it is converged it plays several roles - decreases the amount of the air that decreases drag, increases the air teperature and accelerates the air as a converged nozzle producing thrust.

 

I must emphasize that only two factors can produce THRUST - significant heat input and converged nozzle.

 

Yo-Yo I do understand :smilewink:, I just wanted to point out on the specifics of the P-51 radiator design to David without going into too much detail.

 

I am back to the P-51 after I was flying it a lot in the beta version, there are certainly many changes and improvements since then (FF and proper overheating effects for one) and I enjoy it very much again now and I find this thread very useful. Thank you very much! :thumbup:

[bluepilot76]

Great thread. Complicated stuff.

 

Can you improve engine cooling by using the mixture in the fully - fully forward condition, I forget what its called and no manual to hand.

[Yo-Yo]

Great thread. Complicated stuff.

 

Can you improve engine cooling by using the mixture in the fully - fully forward condition, I forget what its called and no manual to hand.

 

It could be strange - but yes, heat distribution is affected by mixture in the model. The only thing is that FULL RICH means NO ALTITUDE CORRECTION, so the mixture will become stronger as you climb. THe point is that the mixture is rich even at SL (at MIL). Getting it more rich you will lose power starting from the certain altitude.

[Fakum]

Please do not confuse other guys if you did not understand some things. The gauges work and their readings are correct.

 

The reason of keeping the rads manually open is explained above. Surely one can hold them in AUTO... but I have advised.... Don't be surprised when the scoop closes itself. :) Sensors are so vulnerable. Not very often, but....

 

YO-YO, I am not here to fence with you, I respect your position and input, and you are correct, I dont understand some things, thats why I ask questions Like" why cant we just use auto during combat manuevering"? Its still confuses me, especially since I trailed this thread"

http://forums.eagle.ru/showthread.php?t=99465

for quite some time, and the moderator "sobek"has claimed we should ignore some things on the guages. I dont have to read much more to be confused, seems the are some misconceptions about the Auto cooling function and also the acuracy of some temp guages, thats what I read anyway.

 

I just cant imagine (not suggesting real pilots didnt, because I dont know) pilots in a dogfight working the toggle switches from Auto to Manual while trying to manuever to make a kill or keep from being killed? Otherwise, I admit I dont get either right now. Am I expexted to flip the switches myself in combat manuevers, can I trust what I see on the guages? I dont know anymore.

[EvilBivol-1]

The primary reason Yo-Yo recommends setting the radiators manually to OPEN during combat is as a precaution in case of battle damage where the regular becomes faulty. It's better to have them get stuck in the fully open position than closed or operating irredically and causing problems.

 

From earlier in this thread:

A good idea is to manually open both radiators and leave them in MANUAL. It will not give advantage but prevents possible scoops erratic work after battle damages. Of course, one can regularly check temperature gauges especially after impacts... it's up to you.

[Fakum]

Ok, Thanks for that response, so how long are you supposed to hold it open before you let it release to its ceter position?

What about the topic of accuracy of the temp guages themself? Are some still to be ignored as previously posted? Thanks

[Smokin Hole]

If you are in combat, chances are all doors will be open. So what sort of damage could possibly close the doors? I've heard of plenty of cases where the P-51 suffered coolant system damage. The radiator was, after all, the Achilles heal of that airplane. But the door thing seems suspect to me. To the designers as well apparently, which is why they spring-loaded the switches.

[recoilfx]

What sort of damage? Sensor damage?

 

Besides, there is just not enough speed penalty from fully opened radiator during a T&B fight. Also, Heat builds up insanely fast, and I'd rather not have the slow moving radiator flaps trying to catch up.

[sobek]

the moderator "sobek"has claimed we should ignore some things on the guages.

 

"Some things" being the green arc on the oil temp gauge, because it does not correspond with anything, it has no meaning. This is still true.

 

Go back to that thread and read my statements again please, because i never even hinted at that the gauge readings would be incorrect.

 

Besides, i am not particularly happy about the way you are putting words in my mouth in this case. If you are unsure about what a post is supposed to mean, use quotes instead of paraphrasing.

Edited March 14, 2013 by sobek

[recoilfx]

"Some things" being the green arc on the oil temp gauge, because it does not correspond with anything, it has no meaning. This is still true.

 

I've been running my engine during combats at mid-high red line for a while now, so far no seizures!

[Invisibull]

I understand the rationale of opening air outlet doors manually, but what i don't get is why the auto setting NEVER seems to open them enough during potential overheat situations. I've overheated plenty while in auto, but next to never after having opened both the coolant and oil cooling air outlet doors up wide.

 

By way of example - I'm flying along in full mil, both outlet switches set to auto. Maybe I'll do a 45 degree climb or some pretty tight turns. Things, as expected, heat up rapidly. But wait, if i push both momentary switches forward to open their respective air outlet doors, eureka, all the gauges retreat back into the green (Contingent upon going into a dive or resuming wings level flight to increase airflow of course). No overheat. Same exact scenario, except switches are left in auto, more often than not, I'll overheat. What gives?

 

The Mustang manuals (both the actual USAAF manual and DCS's incredibly close reproduction of same say the following:

An outlet door on the bottom of the air scoop controls the oil temperature. Under ordinary conditions this door is operated automatically. However it can be operated manually when running the engine on the ground or in case the automatic regulator fails in the air.

 

This suggests that the automatic regulator should indeed accommodate any heat load that manual operation could handle whilst in flight. As long as the auto setting can open the doors fully the same as I'm doing in manual, what's the difference, right? Am I missing something or does is the auto setting in the sim not working as it should?

[sobek]

The cooler flap controllers are simple hysteresis type and therefore have strong limitations. I expect this would be the same for the RL aircraft.

[EvilBivol-1]

As the system is not for exact keeping the exact temperature value, the actual temperature will be anywhere within the limits< and it depends on history and how fast you add power, etc, etc. THe normal situation is when the temperatures are below red ticks. At transition you can get it higher - it's normal. Imagine that you significantly reduce MP diving and make it slowly. The temperature will be catched near upper limit as the scoop almost completely closed. If you set MIL or WEP and begin to climb loosing speed the scoop can not be so fast to chase the increased power... so the temperature can escape throught the red tick. for a while.

 

And, by the way, the radiator drag will be zero or even negative only at high power ratings and high speed. The radiator installation works as a ram-jet. Compressing and heating then converged nozzle - it's a ram-jet.

http://forums.eagle.ru/showpost.php?p=1689859&postcount=16

[Invisibull]

OK, I understand that point. Thanks, gents.

[Weta43]

Typing n the wrong thread

[DerHesse70]

I played around with the manually cooling (oil and coolant) the last days an realized something.

 

If i switch in combat to manually and hold the switch it opens the doors. If i release the switch it jumps to the middle position. In this middle position the temperatures also didn't increase (respectively decrease if they were to high before). So i think the position of the doors will still held! If i push the switch to auto it activates the auto mechanism again.

 

Is my observation right, that the outlet doors don't change there last position (from close or open) if i release the switch and it jumped into middle position. I only hold the switch in open or close to move the door into the end position. If i release there is nothing active and the door holds his current position.

 

Since i use the manually position for coolant and oilcooler in combat i never had a broken engine again!!

[Robo.]

Is my observation right, that the outlet doors don't change there last position (from close or open) if i release the switch and it jumped into middle position. I only hold the switch in open or close to move the door into the end position. If i release there is nothing active and the door holds his current position.

 

Yes that is exactly how it works - Up = auto, down = manual / neutral position. In down position you can move the shwitch back and forth to close / open the radiator. It will jump back to neutral position when you release the switch. You're spot on! :thumbup:

[Kwiatek]

I played around with the manually cooling (oil and coolant) the last days an realized something.

 

If i switch in combat to manually and hold the switch it opens the doors. If i release the switch it jumps to the middle position. In this middle position the temperatures also didn't increase (respectively decrease if they were to high before). So i think the position of the doors will still held! If i push the switch to auto it activates the auto mechanism again.

 

Is my observation right, that the outlet doors don't change there last position (from close or open) if i release the switch and it jumped into middle position. I only hold the switch in open or close to move the door into the end position. If i release there is nothing active and the door holds his current position.

 

Since i use the manually position for coolant and oilcooler in combat i never had a broken engine again!!

 

So probably auto mode work dont like should?

 

I notice during online dogfight that when i respawn in the air and set military power after a very short time with normal manouver flying ( 250-300mph) i got red line in coolant guage - i checked external view and saw that radiator door are near close position - it was long time when it was opened for full even if i got redline coolant temperature much eariler

 

Once time when i respawned set military power and try to dogfight with enemy plane i got engine broken after not more then 2 minutes.

 

I think that something is not right with auto position of radiator.

[Yo-Yo]

I played around with the manually cooling (oil and coolant) the last days an realized something.

 

If i switch in combat to manually and hold the switch it opens the doors. If i release the switch it jumps to the middle position. In this middle position the temperatures also didn't increase (respectively decrease if they were to high before). So i think the position of the doors will still held! If i push the switch to auto it activates the auto mechanism again.

 

Is my observation right, that the outlet doors don't change there last position (from close or open) if i release the switch and it jumped into middle position. I only hold the switch in open or close to move the door into the end position. If i release there is nothing active and the door holds his current position.

 

Since i use the manually position for coolant and oilcooler in combat i never had a broken engine again!!

 

THere is a little trick one must keep in mind. For example, you warmed up the engine and then you are taxiing to the start. The temperature is still A LITTLE BIT below the upper limit for auto scoop opening, so it's fully closed. Then you engage full throttle to take off throwng tremendous amount of heat into the radiator.

It must be fully open to dissipate it but actually it is closed and goes to open position as a snail. 20 long seconds!

20 long seconds coolant temperature raises up to overheat.

 

The hint is very simple. Never warm up staying where you start the engine. 1000 rpm is good either for warming up or to taxiing. Anyway, before the TO run take a look at the coolant/oil temperature. If it's already close to upper limit it would be better to manually open them and then return to AUTO just before the run.

[Yo-Yo]

So probably auto mode work dont like should?

 

I notice during online dogfight that when i respawn in the air and set military power after a very short time with normal manouver flying ( 250-300mph) i got red line in coolant guage - i checked external view and saw that radiator door are near close position - it was long time when it was opened for full even if i got redline coolant temperature much eariler

 

Once time when i respawned set military power and try to dogfight with enemy plane i got engine broken after not more then 2 minutes.

 

I think that something is not right with auto position of radiator.

 

It's a well known input bug. I never encountered it but some users did. Probably it depends on something in operation system, I have no idea. Switching helps. You even must mot open it. Just touch the switch and return to AUTO.

[Fakum]

"Some things" being the green arc on the oil temp gauge, because it does not correspond with anything, it has no meaning. This is still true.

 

Go back to that thread and read my statements again please, because i never even hinted at that the gauge readings would be incorrect.

 

Besides, i am not particularly happy about the way you are putting words in my mouth in this case. If you are unsure about what a post is supposed to mean, use quotes instead of paraphrasing.

 

My deepest apologies sobek, I meant no disrespect, nor did I intend to put words in your mouth. Re-reading that thread several times did not clarify my point at all, I will attribute that to my lack of comprehension. There still seemed to be some confusion by others, so I know its not just me. Either way, I did the best I could here to collect some of your quotes and attach them here just as you suggested I do. This wont clear anything up I suppose, but it will at the very least show why I stated what I did, as you can see from your quotes, there are mentions of confusion with markings of temps vs actual temps, and oil temp gauge to be ignored. Perhaps you can understand why I am inquiring still because I have seen mention in other sections that these are now accurate, but I never seen that claim in the original thread that these quotes were derived. So am I confused, yes, sorry to have dragged you into this, but I was simply looking for confirmation, now im not sure at all. And I will leave it at that. Im not here to cause problems, Im here to understand them and help out where I can. I wont pursue this matter any further. Thank you for your input just the same. Respectfully,,,,,

There was some confusion with the markings on the temp gauges and the actual working temperatures, in case of the oil temp gauge, those do not match. People concluded that the regulator was faulty and resolved to regulating manually, when in fact, it was working.

The sim works according to RL documentation. Why the marks are where they are on the gauge that was used as reference is still the cause for some confusion, AFAIK.

No. Change it to "the green arc on the oil temp gauge is to be ignored", the answer is, AFAIK, yes.