P-47 running hot lately?

[RyanR]

I've cooked the engine in a few D-22's lately. I don't recall ever having this problem. If anything, I had trouble keeping heat in the engine as it was overcooling at altitude with all the shutters closed.

 

Lately, the oil temps are hard to keep in check. They're always between 80-100 degrees with just cruise power, turbo off, and all the shutters open. It's summer on the Normandy map, so temps at sea level are pretty hot, but only 0-10F at altitude. Once the turbo spools up, there's just a few minutes before the oil temp redlines. Technochat offers no warning, and the engine just stops. I hadn't even pulled the water injection. (should I be using water injection?).

 

Also running 150 octane fuel, so I am seeing higher manifold pressures than without. Could there be a problem there?

 

Thanks!

 

-Ryan

[FuriousMeow]

Just did a small QMB scenario last night to re-familiarize myself with the P47. It was the D-22 over the Normandy D-Day map. Small escort against 190A6s. I would play with the cowl flaps but they were mostly closed, used 150 fuel, oil was mostly closed and the intercooler flaps I ran completely closed during combat. It wasn't until after all 190s were down and RTB I realized they should be neutral. Other than a blue falcon AI that pinged up my wing tip, I downed all 3 190s between 18K and 12K running at 2700RPM and full open throttle - I think 70MP? The only time I saw the heat rise to almost 100 was when I did a lot of vertical maneuvers that decreased air flow which is when I'd play with the cowl flaps. Other than that, about 10 or so minutes of fighting, then back across the channel at 2550RPM and 51MP with cowl flaps closed, oil slightly open and intercooler at neutral, never had any engine issues. Ran full turbo the whole time.

[DD_Arthur]

2 hours ago, RyanR said:

Lately, the oil temps are hard to keep in check. 

Check your mixture lever.

[RyanR]

15 hours ago, DD_Arthur said:

Check your mixture lever.

 

 

I'm usually in auto-rich. Should I go full-rich to cool the charge?

 

-Ryan

 

[Lusekofte]

Auto rich should be enough. Full rich depends on altitude. Radials get cooled by fuel and you notice a difference climbing on a/lean and a/ rich but not enough to get a problem between full rich and auto. 

[bringerofpain]

I found that auto rich is good if you go any higher you can overheat your engine, and black smoke behind your plane.

[RyanR]

21 hours ago, FuriousMeow said:

Just did a small QMB scenario last night to re-familiarize myself with the P47. It was the D-22 over the Normandy D-Day map. Small escort against 190A6s. I would play with the cowl flaps but they were mostly closed, used 150 fuel, oil was mostly closed and the intercooler flaps I ran completely closed during combat. It wasn't until after all 190s were down and RTB I realized they should be neutral. Other than a blue falcon AI that pinged up my wing tip, I downed all 3 190s between 18K and 12K running at 2700RPM and full open throttle - I think 70MP? The only time I saw the heat rise to almost 100 was when I did a lot of vertical maneuvers that decreased air flow which is when I'd play with the cowl flaps. Other than that, about 10 or so minutes of fighting, then back across the channel at 2550RPM and 51MP with cowl flaps closed, oil slightly open and intercooler at neutral, never had any engine issues. Ran full turbo the whole time.

 

 

Any idea what the ambient temps were? I usually just run oil coolers open, neutral intercooler, and closed cowl flaps.

 

I think the problem in my case is that it's July, 1943 in PWCG and ambient temps are just *hot*. The carb temps are 30 degs C with the turbo off at low alt. I noticed things seemed better with water injection and its extra inch or two of manifold pressure. That's a little counterintuitive, but it makes sense. With 150 octane, manifold pressures can get darn near "boost" level. I guess I'm just not used to running the top shelf fuel.

 

Thanks all!

 

-Ryan

[69th_Mobile_BBQ]

I forget if the mission information tab on the operational map gives weather information in singleplayer campaign mode, but in singleplayer quick mission, there is none. 

 

IIRC the listed "optimal" climb speed of the p47 is around 160-170mph but, this is often times too slow to keep enough airflow passing through the engine compartment / radiator system.   If you are in-the-climb after taking off or resetting altitude after a low altitude fight, I'd suggest trimmimg the plane to climb slower over a longer distance and at a speed (at the very least) of around or above 225 mph.   

Sustained turning at lower speeds also disrupts the airflow and reduces heat dissipation so, try to only turn when it gives the most advantage.

 

1 hour ago, bringerofpain said:

I found that auto rich is good if you go any higher you can overheat your engine, and black smoke behind your plane.

 

This is correct, while some engines don't gain extra heat from full mixture, other designs need a more 'balanced' setting or too much mix will no longer have a cooling effect and go entirely in the opposite direction, adding excess heat.   

 

Besides, it's an American plane.  Fast, Loud and Dirty is the order of the day.   If you're running the engine settings at max continuous, ie; just below kicking into combat mode, and your exhaust is totally clean, you're setting is too low and you're adding heat. 

I do understand that nobody wants to be dragging a big black flag behind their plane when they're trying to not be seen but, it's often times just something that needs to be accepted.  Besides, if you are already seen and about to enter combat, make sure your mix is set in Auto Rich asap.  The enemy already sees you and you need the engine to work properly by that point anyway.  

Edited February 16, 2023 by 69th_Mobile_BBQ

[69th_Mobile_BBQ]

19 minutes ago, RyanR said:

 

 

Any idea what the ambient temps were? I usually just run oil coolers open, neutral intercooler, and closed cowl flaps.

 

I think the problem in my case is that it's July, 1943 in PWCG and ambient temps are just *hot*. The carb temps are 30 degs C with the turbo off at low alt. I noticed things seemed better with water injection and its extra inch or two of manifold pressure. That's a little counterintuitive, but it makes sense. With 150 octane, manifold pressures can get darn near "boost" level. I guess I'm just not used to running the top shelf fuel.

 

Thanks all!

 

-Ryan

 

You should never be running without some level of turbo running as well.  The turbo is a big factor in influencing the manifold pressure.  It also insures that the air flowing through the cooling system isn't 'bottlenecking' in the piping that runs through the plane.  If you notice, the boost has a big effect on the turbo RPM, which feeds the manifold pressure.   The engine will cool for a short time with the boost on if the turbo was completely off because with the turbo now spinning, the hot fumes that were simply 'leaking' out of the cooling system are now flowing properly.   After that initial release of the pent-up hot gasses, the boost itself should become the factor that begins to build excess heat over time so, keep the turbo going at all times and don't overdo the boost unless you need all the power you can get.

[FuriousMeow]

21 hours ago, RyanR said:

 

 

Any idea what the ambient temps were? I usually just run oil coolers open, neutral intercooler, and closed cowl flaps.

 

 

 

Not sure, it was QMB so if the map temps change on each load then may not be of much help to go back and look unfortunately. If they don't change ranodmly then its whatever the set atmo is for the D-Day specific Normandy map.

[Supercharger]

P-47 is very heat sensitive airplane, it drains performance more than on any other aircraft under hot weather conditions. But on the other hand, if its cold, it is quite fast and powerful. 

[RossMarBow]

Seriously
Has none suggested opening up the oil radiator yet?

Common guys think!

 

Combat cruise setting should be
600L
rpm 66-84% pressure 100% turbo 100% front cowls closed rear cowls 50% oil 1-33%

auto rich

engine timers will run out about the same time as you run out of fuel 

 

full rich gives you more power
water boost gives you more power


The only time you should be increasing rpm above 84% is if you are below combat cruise speed and climbing - i.e. just don't do this ever
Engine timers are too short and you should rtb for a new plane straight away

 

If you are planning on spending a lot of time in the air dial back the pressure and run auto lean for green engine settings.

[RyanR]

4 hours ago, RossMarBow said:

Has none suggested opening up the oil radiator yet?

I didn't sat it specifically, but by "all shutters open" I implied that the oil was open as well. Thanks for the tips! I'll go full rich next time I'm "up".

 

What I did find is that summer BoK map approximates the sea level temps that I was seeing in BoN. Quick experiment: Full speed ahead, skimming the waves at 300IAS. Speed up time to 8x. With 150 octane ate full throttle, the plane will overheat. Engage water injected boost, and oil temps come down.

 

The takeaway is that with 150 octane fuel, you can get the manifold pressure high enough at full combat power that the engine will overheat. Soooo... use water injection sooner if the plan is to sustain that power level. The "built-in career", doesn't let you have the high-octane fuel, so I'm just not used to running manifold pressures this high. PWCG also opens the door to a lot more opportunities for aerial combat, so I'm also pushing the plane hard for longer.

 

Thanks!

 

-Ryan

 

[RossMarBow]

Still strange Kuban autumn map it won't overheat at all.

 

What RPM are you running? If you are flying straight and level you should be dialling back the RPM that will reduce heat.

 

Also 300mph seems a little slow for max speed.

 

Fully stripped the razorback combat cruises at over 600 kph.

 

I think you might be overheating cause you have too much drag or something.

 

 

In multiplayer I leave pressure at 100% and oil at 5% with 150oct for the entire time and never have hot oil.

 

Edited February 19, 2023 by RossMarBow

[Supercharger]

On 2/18/2023 at 12:18 PM, RossMarBow said:

rpm 66-84% pressure 100% turbo 100% front cowls closed rear cowls 50% oil 1-33%

You keep the engine running at full throttle with oil and intercoolers partially closed? And then modulating the engine speed? Are we playing differnt games? 

If i would do so...my engine will quit in seconds.

[RyanR]

16 hours ago, RossMarBow said:

 

Also 300mph seems a little slow for max speed.

 

 

 

 

 

Yeah.... it was probably faster. I was only watching the oil temp gauge. Usually see 340 when going full speed ahead on the deck.

 

I forget the settings in the plane for my "experiment", but I intentionally had things set up to break the engine. I wanted to see if water injected boost mode ran cooler than just "plain" full throttle. It did. Temps went up towards red line, shove her into "boost" and temps came down. Not surprising considering how high manifold pressures get with 150 octane.

 

Dialing back the prop speed to 85% seems to help keep oil temps down without noticeable loss in speed/power. Keeping the oil coolers open at lower alts doesn't seem to affect speed.

 

Thanks!

 

-Ryan

[RyanR]

 

 

A bit of closure: During another excellent PWCG mission, we jumped some 190's. I took your tips to heart: full-rich, prop at 85%, oil and intercoolers at 100%, per wartime training videos, I simply locked the turbo and throttle levers together. I got less shy about using up the precious water injection, so I engaged that anytime I was halfway into combat power. Results speak for themselves: Oil temps are under 70C after flogging her pretty good. Got two A-5's and an A-6. Wingman got the fourth.

 

Thanks again!

 

-Ryan

 

 

[Art-J]

What does 85% correspond to in RPM (for guys like me who don't use technochat and rely on instruments)? Is it 2550 like seen on the screenshot?

[CUJO_1970]

On 2/16/2023 at 4:59 PM, RyanR said:

I think the problem in my case is that it's July, 1943 in PWCG and ambient temps are just *hot*. The carb temps are 30 degs C with the turbo off at low alt. I noticed things seemed better with water injection and its extra inch or two of manifold pressure. That's a little counterintuitive, but it makes sense. With 150 octane, manifold pressures can get darn near "boost" level. I guess I'm just not used to running the top shelf fuel.

 

 

Shouldn't be running 150 grade aviation fuel anyway, at least if you are trying to keep things "historic".

[RyanR]

8 hours ago, Art-J said:

What does 85% correspond to in RPM (for guys like me who don't use technochat and rely on instruments)? Is it 2550 like seen on the screenshot?

 

Exactly that. I use instruments mostly, but technochat gives a little bit of feedback until I get a throttle quadrant. 2550 is the top end of "normal" engine mode for the jug. Any more and you're in combat mode.

 

4 hours ago, CUJO_1970 said:

 

Shouldn't be running 150 grade aviation fuel anyway, at least if you are trying to keep things "historic".

 

I've played through IL-2 several ways in "historic" mode. Now I'm enjoying shaking it things up a little.

 

-Ryan

 

 

 

[czech693]

You didn't get any shaking with the intercooler gates open at high speed?

[RyanR]

12 hours ago, czech693 said:

You didn't get any shaking with the intercooler gates open at high speed?

 

No shaking with the intercoolers, but the cowl flaps shake like mad at 225mph.

 

-Ryan

[Rei-sen]

Running hot is probably on the very bottom of the list of issues that P-47 has in this "sim", lol

[Supercharger]

15 hours ago, czech693 said:

You didn't get any shaking with the intercooler gates open at high speed?

Me too, but only at speeds above 400mph with the intercooler fully open.........i got this issue on diving attacks frequently

[RossMarBow]

On 2/20/2023 at 6:10 AM, RyanR said:

 

 

Yeah.... it was probably faster. I was only watching the oil temp gauge. Usually see 340 when going full speed ahead on the deck.

 

I forget the settings in the plane for my "experiment", but I intentionally had things set up to break the engine. I wanted to see if water injected boost mode ran cooler than just "plain" full throttle. It did. Temps went up towards red line, shove her into "boost" and temps came down. Not surprising considering how high manifold pressures get with 150 octane.

 

Dialing back the prop speed to 85% seems to help keep oil temps down without noticeable loss in speed/power. Keeping the oil coolers open at lower alts doesn't seem to affect speed.

 

Thanks!

 

-Ryan

Just clarifying a few things.
Cause people are picking and running with the wrong numbers.

RPM should be 84% and lower - for max speed horizontal 
If RPM is higher than 84% you are slowing the plane down - if you are flying in a straight line.

As long as you stay below 84% RPM you will get at least 30min out of the engine.
At full boost.
Obviously water and fuel are a limiting factor in terms of time - but running full rich with water is fastest. 

 

Running over 84% takes you into the higher engine timer bracket and severely reduces time before damage.

 

 

As with all manual RPM engines reducing rpm below optimum i.e. 84% while maintaining full boost
Allows for fuel saving, temp saving, for little loss in speed if you are flying horizontal. 

So you can run this plane though 600L+ at its max speed for over 30min no problems.

I don't have the exact amount of fuel I take handy, but I take just enough fuel for this configuration, that way as my fuel starts getting low I know I'm close to running past the orange combat timer. 

 

 

Regarding the confusion about cowl flaps.

 

Front flaps should only be opened on the ground.
The rear "cowl" flap is the intercooler air flow controller - it should be at the neutral position which is 50%.

 

If you fly it correctly like this the razor back is the fastest plane in the game over long distances by a long shot.


 

On 2/26/2023 at 5:10 PM, czech693 said:

You didn't get any shaking with the intercooler gates open at high speed?

Why are you even doing that?

On 2/23/2023 at 7:54 AM, Art-J said:

What does 85% correspond to in RPM (for guys like me who don't use technochat and rely on instruments)? Is it 2550 like seen on the screenshot?

84% like I said
its an exact figure don't round it up just cause

On 2/22/2023 at 9:29 AM, RyanR said:

 

 

A bit of closure: During another excellent PWCG mission, we jumped some 190's. I took your tips to heart: full-rich, prop at 85%, oil and intercoolers at 100%, per wartime training videos, I simply locked the turbo and throttle levers together. I got less shy about using up the precious water injection, so I engaged that anytime I was halfway into combat power. Results speak for themselves: Oil temps are under 70C after flogging her pretty good. Got two A-5's and an A-6. Wingman got the fourth.

 

Thanks again!

 

-Ryan

 

 

Please re-read what I have said 
Because your still not getting the most out of it
In fact your severely handicapping yourself

On 2/23/2023 at 7:54 AM, Art-J said:

What does 85% correspond to in RPM (for guys like me who don't use technochat and rely on instruments)? Is it 2550 like seen on the screenshot?

This will tell you

[czech693]

I don't fly with intercooler flaps open (I usually keep them at neutral).  I questioned that action as it is not recommended due to shaking, plus I remember watching a video where the plilot could barely keep his sights on after a high speed dive with the flaps open.

[RyanR]

What I hadn't realized is how warm the engine runs at auto-lean when going to and from the combat area. You really have to pull the power back. Auto-rich cured that. Kind of a "duh", but I'm learning.

 

I'll open the intercooler flaps to full from neutral when maneuvering at full power, then back to neutral when the speed comes up again.

 

85% prop doesn't kick it into combat power on my end, but I've been at 84%. Oil coolers at 100% doesn't seem to add drag. Cowl flaps closed.

 

It's a lot of fun flying the Razorback over the BoN map in 1943 with PWCG. Amazing how lively the plane becomes once you shed the bombs on the target.

 

-Ryan

[RossMarBow]

On 3/10/2023 at 5:43 AM, RyanR said:

What I hadn't realized is how warm the engine runs at auto-lean when going to and from the combat area. You really have to pull the power back. Auto-rich cured that. Kind of a "duh", but I'm learning.

 

I'll open the intercooler flaps to full from neutral when maneuvering at full power, then back to neutral when the speed comes up again.

 

85% prop doesn't kick it into combat power on my end, but I've been at 84%. Oil coolers at 100% doesn't seem to add drag. Cowl flaps closed.

 

It's a lot of fun flying the Razorback over the BoN map in 1943 with PWCG. Amazing how lively the plane becomes once you shed the bombs on the target.

 

-Ryan

I don't know why you are adjusting the intercooler.
I don't think you need to do anything to it, other than set it to 50%/neutral.
And I have never heard of anyone adjusting it for any reason.
But happy to learn something new if its actually beneficial to performance.

Mixture works extremely well at cooling all the plane's engines.

I'm strictly a multiplayer guy, so running lean has some advantages with being harder to track.
But generally, it's just worth running rich - the bonus engine power and reduced drag far outweighs the cons.
I believe every engine except the 51B has more power at full rich. But the p47 has the most obvious speed increase at full mix.

With the p47s performance window its almost always best to take a huge amount of fuel so you can increase your horizontal speed.
As you're not catching anything in a climb even without an extra 500L weighing you down.
Something I never seriously experimented with, but in theory would be super viable is just taking an insane amount of fuel and running full rich for the duration of the mission.

 

Oil I think you can open up to ~33% with no extra drag at all, otherwise it's about 5kph at 100%.
Personally, I never had issues with oil temp, although lots of people seemed to think I was crazy leaving it at 5% for the duration of the mission.

 

It is a really fun plane once you get it setup.
Its ability to maintain a high speed for a very long time makes it pretty amazing.

 

Generally, how I fly it in multiplayer is depending on what grade fuel I get - take a loadout that gives me a cruise speed that is faster than the 109s cruise speed.
Which might involve removing guns or only taking 2 bombs.
Take off climb hard into the 190 sc gap. Highspeed cruise to target. Drop bombs. Join in furballs, avoid 1v1s. Run home on deck.
As long as you play to its strong suit - higher speed than any other prop plane over 30min - it's a good time.

Edited March 11, 2023 by RossMarBow

[RyanR]

11 hours ago, RossMarBow said:

I don't know why you are adjusting the intercooler.
I don't think you need to do anything to it, other than set it to 50%/neutral.
And I have never heard of anyone adjusting it for any reason.
But happy to learn something new if its actually beneficial to performance.

 

Honestly, I just leave it at neutral now. Hard to say what benefits it actually brings full open, and there are definite drag penalties if you forget to re-close them back to neutral. It does bring the needle on the carb temp gauge down quite a bit, but whether or not that's "modeled" in the sim is anyone's guess. The intercoolers on the P-38 do nothing.... and I think that's the only other plane with a turbo.

 

-Ryan

 

 

[354thFG_Panda_]

1 hour ago, RyanR said:

 

Honestly, I just leave it at neutral now. Hard to say what benefits it actually brings full open, and there are definite drag penalties if you forget to re-close them back to neutral. It does bring the needle on the carb temp gauge down quite a bit, but whether or not that's "modeled" in the sim is anyone's guess. The intercoolers on the P-38 do nothing.... and I think that's the only other plane with a turbo.

 

-Ryan

 

 

 

At high altitudes opening the P-47s intercooler (from 50% to 55~60) results in a very small increase in speed so it is modelled even if its negligible 

Edited March 11, 2023 by theRedPanda