Engine Blowing up from no apparent reason

[303_Kermit]

Dear Sirs!
I have a problem, and I can't find solution or reason for it. It happened 2-nd time in 2 days. What am I doing wrong?

P-47D30 Early Straight flight / gentle climb, without dive. Multiplayer, 4Ya Overlord.


-2300rpm
-manifold 50
-oil pressure "blue", oil temp "blue", air temp intercooler "blue", turbo about 1400 RPM.

loud "kaboom" from behind a cockpit:
["failureDisplayName"] = "Engine #1 erroneous ignition timing induced damage", ["t"] = 10579.065, ["target"] = "P-47D-30bl1", ["targetMissionID"] = "596", ["targetPilotName"] = "=Crow=Kermit", ["target_coalition"] = 2, ["target_object_id"] = 16777475, ["target_unit_type"] = "P-47D-30bl1", ["target_ws_type1"] = 1, ["type"] = "failure", ["weapon"] = "Aw shoot.",
 

second kaboom behind a cockpit:
["failure"] = "ENG0_DAMAGED_BEYOND_REPAIR", ["failureDisplayName"] = "Engine #1 damaged beyond repair", ["t"] = 10579.065, ["target"] = "P-47D-30bl1", ["targetMissionID"] = "596", ["targetPilotName"] = "=Crow=Kermit", ["target_coalition"] = 2, ["target_object_id"] = 16777475, ["target_unit_type"] = "P-47D-30bl1", ["target_ws_type1"] = 1, ["type"] = "failure", ["weapon"] = "Aw shoot.",

"boost" throttle goes down:
["failure"] = "ENG0_MAIN_BEARING_DAMAGED", ["failureDisplayName"] = "Failure.ENG0_MAIN_BEARING_DAMAGED", ["t"] = 10579.065, ["target"] = "P-47D-30bl1", ["targetMissionID"] = "596", ["targetPilotName"] = "=Crow=Kermit", ["target_coalition"] = 2, ["target_object_id"] = 16777475, ["target_unit_type"] = "P-47D-30bl1", ["target_ws_type1"] = 1, ["type"] = "failure", ["weapon"] = "Aw shoot.",

engine stops:

["initiatorMissionID"] = "596", ["initiatorPilotName"] = "=Crow=Kermit", ["initiator_coalition"] = 2, ["initiator_object_id"] = 16777475, ["initiator_unit_type"] = "P-47D-30bl1", ["initiator_ws_type1"] = 1, ["t"] = 10600.145, ["type"] = "engine shutdown",

P-47 CKBWL.log

Edited January 14, 2023 by 303_Kermit

[Nealius]

11 hours ago, 303_Kermit said:

-2300rpm
-manifold 50

Boost too high RPM too low. Cylinder heads could have been too hot, you didn't mention what temp those were. If you're going up to 50" manifold pressure your prop pitch lever should be max (2700).

Edited January 15, 2023 by Nealius

[303_Kermit]

5 hours ago, Nealius said:

Boost too high RPM too low. Cylinder heads could have been too hot, you didn't mention what temp those were. If you're going up to 50" manifold pressure your prop pitch lever should be max (2700).

 

Cyl. heads 190°C - thanks for mentioning.
All you wrote, sounds logic, but only at first glance
How do you explain, that I can fly from T-O till landing with full throttle (main and boost) forward on, manifold 52-54, RPM 2300-2500 until I burn whole the fuel in main and auxiliary? Problem appears only when I try to fly "by the book". Only when I try to save some fuel, by using "auto lean", lower rpm and manifold. Like during long escort mission, with auxiliary tanks. Using more power only if really needed.
If I fly like an Idiot, full throttle whole the time, P-47 works just fine.

Here are more information about R-2800 like the one:
"Just prior to World War II, Frank Walker was responsible for the development of anti-detonation injection (ADI) for the R-2800. ADI forces a water-alcohol mix into the induction system to cool the supercharged fuel-air mixture, thereby allowing a much higher manifold pressures and power outputs. Using ADI, Walker was able to coax 3800 HP from an experimental “C” engine at manifold pressures up to 150 in Hg!1 This is nearly twice the power the engine was designed to produce. In addition to its reputation for ruggedness in aircraft like the P-47, the R-2800 developed a reputation for reliability in airline service after World War II. It had a recommended time between overhauls of 2000 hours on twin-engine aircraft, and 3000 hours on 4-engine aircraft."
Source: 
1. Frank Walker, interview by author (Huntsville, AL, March 29, 1999)

2.R-2800 Engine Reliability, internal memorandum to Pratt & Whitney Field Service Personnel (December 21, 1967)

More you may find in these documentation:
http://www.enginehistory.org/NoShortDays/Development of the R-2800 Crankshaft.pdf

The more I read about Double Wasp the less I find common sence in DCS R-2800 damage model. There is a lot about vibrations (Linear and Torsional X1, X1,5, X2, X3,5...) and struggle during development to overcome it. But main rod bearing lubrication, doesn't look like any serious problem in case of Double Wasp.

Edited January 15, 2023 by 303_Kermit

[iFoxRomeo]

17 hours ago, 303_Kermit said:

-2300rpm
-manifold 50

By the book?

Which book says 2300/50?

[Nealius]

I fly by the book numbers and don't have any issues. 

[303_Kermit]

2 hours ago, Nealius said:

I fly by the book numbers and don't have any issues. 

Good for you. You helped.

[303_Kermit]

3 hours ago, iFoxRomeo said:

By the book?

Which book says 2300/50?

I left the link. There's much more what pilots did to these engine without blowing it up. Its reliable was legendary. 2300/50 isn't anything beyond flight manual. Engine delivers bit less power than by 2800RPM, nothing else. I would be glad to fly 2800/50, but it changes nothing accept engine blows up in dive.

The document comes from the website of Historical Engines Association (US). There are also other documents there. Like R-2800 (exploitation) bulletin, and much more. I see nothing similar to DCS in them.

Edited January 15, 2023 by 303_Kermit

[Nealius]

1 hour ago, 303_Kermit said:

Good for you. You helped.

Lose the attitude. Your're handling the engine incorrectly. Use the settings on p.119 (doesn't include WEP).

Also take a look here, since you're overspeeding the prop as well.

[303_Kermit]

23 minutes ago, Nealius said:

Lose the attitude. Your're handling the engine incorrectly. Use the settings on p.119 (doesn't include WEP).

Also take a look here, since you're overspeeding the prop as well.

Thank you - nice manual, but it's not the flight manual. It's just instruction for DCS Module, and yes I know chuck guide.

Eather I'm not good in English as I think I am, or you desperately try not to understand me.

The situation is: I fly 30-45min. Escort mission. Auto lean - 35 manifold - 25000-28000ft - 190-200°C Cyl Heads, 2300RPM.
I see some contact, auto reach, BOOST 50, radiators, cowl flaps, intercooler :set. Temperatures are ok I check again in 15sec. and adjust. straight flight without dive
If I use max RPM engine will die in dive. If I use 2300RPM-2600RPM (depend on turbo overspeed) engine works fine - most of the time. It is funny but I found out, that most breaks down appears when my fuel is down to about 200gal. It happens only by that amount of fuel (if you take off with 100%fuel). If I do the same by let's say 300gal. there is no problem. Engine breaks down only after long flight time with low power. 

I guess 99% here never tried to fly P-47 on long distance mission. The problem I described never happens if you take off with 70% fuel just to dogfight over "P-trap"

[iFoxRomeo]

[razo+r]

1 hour ago, 303_Kermit said:

straight flight without diveIf I use max RPM engine will die in dive. 

Check your RPM and make sure you are not overspeeding your engine while your airspeed is increasing.

[grafspee]

@303_Kermit Engine in P-47 overspeed very easy in high alt high speed dives. Setting lower engine rpm changes nothing in that regard. And if you overspeed engine to 2900 for a short time, engine will die soon

Edited January 15, 2023 by grafspee

[303_Kermit]

3 hours ago, razo+r said:

Check your RPM and make sure you are not overspeeding your engine while your airspeed is increasing.

 

1 hour ago, grafspee said:

@303_Kermit Engine in P-47 overspeed very easy in high alt high speed dives. Setting lower engine rpm changes nothing in that regard. And if you overspeed engine to 2900 for a short time, engine will die soon

 

1. I checked. I am aware that on high altitude even in straight flight it's almost impossible to control RPM - one has to first set RPM, then increase boost.
2. That would understandable reason - I may agree or disagree with FM/DM, but it sounds as logic reason - knowing it one can avoid it. My problem is not how to avoid prop. overspeed. My question is why plane behaves different during long flights. I do the same thing in short flights as I do during B-17 escort, the only difference is, that before raising power I fly a long time with low power setting.

[303_Kermit]

On 1/15/2023 at 5:18 PM, iFoxRomeo said:

Thanks , but I have flight manuals for P-47B/C/D/M... It's not an answer I'm looking for. It's not answering why plane behaves different during long flight than in short (~45min) flights.

However... I have to check the 2-nd point in "Conditions to avoid" - Air Temp. 35°C. That may be a reason

@Edit:
That was it. Thank you for solution.
My greatest respect for the devs, for "paranoid" level of Engine DM accuracy. I love you

 

Edited January 17, 2023 by 303_Kermit

[D4n]

I had a similar thing, I flew for 30-45 min. multiplayer, with all values in green levels, and shortly using WEP a few times (only seconds, for testing, and not the advertised 15 min.) when suddenly a metal chirping sound started and prop stopped. Could the issue be that water for water-injection is disabled in mission file and that causing huge engine stress within only seconds?

[razo+r]

20 minutes ago, D4n said:

I had a similar thing, I flew for 30-45 min. multiplayer, with all values in green levels, and shortly using WEP a few times (only seconds, for testing, and not the advertised 15 min.) when suddenly a metal chirping sound started and prop stopped. Could the issue be that water for water-injection is disabled in mission file and that causing huge engine stress within only seconds?

Check the water pressure gauge to see if its disabled. If there is no water and you push +60 MP, you are overboosting the engine. 

[D4n]

Ok, the gauge moved, so it worked. So it also was the over-RPM on my end then, I stayed a liiiittle longer above 2550 RPM than 5 minutes. I was also very surprised that I'd only reach 250 mph with a full bomb load and only 40% fuel Quite a slow plane, when loaded with 5700 lbs of weapons and 900 lbs of fuel, amazing. It doesn't state anywhere how long one should stay at (or below) 2550 RPM when having flown at 2700 RPM for 5 minutes, right?

[Ala13_ManOWar]

1 hour ago, D4n said:

Ok, the gauge moved, so it worked. So it also was the over-RPM on my end then, I stayed a liiiittle longer above 2550 RPM than 5 minutes. I was also very surprised that I'd only reach 250 mph with a full bomb load and only 40% fuel Quite a slow plane, when loaded with 5700 lbs of weapons and 900 lbs of fuel, amazing. It doesn't state anywhere how long one should stay at (or below) 2550 RPM when having flown at 2700 RPM for 5 minutes, right?

That kind of things aren't usually stated anywhere beyond the 5 minutes limit and so. Think it'd be almost impossible to pinpoint all the infinite variables, what speed you where, and are now? in what atmospheric conditions, Temp, wet, pressure? what time did the engine spent at any regime and what speed you had those moments? All of that can be logged in a PC game, but IRL it's really hard to check every variable and reduce it down to a simple table like you can be 10 minutes, 45, or 2 at @xxxx revs.

I believe it's, for the most, part the pilot's job to bear in mind the conditions you're in at the current flight and guesstimate using your experience and judgement if you should run the engine that extra minute after a long run at 30ºC on Summertime while mowing the lawn, or maybe in a Winter's day at 30.000ft escorting bombers, so one can figure out to some extent what to do or not.

[D4n]

I'd guess that the metal-chirping sound in reality can also gradually increase over the course of several minutes, when the engine is only barely stressed beyond limit, and that giving the pilot time to drastically lower the output and get at least 5 or 10 more minutes for a powered landing instead of how it currently seems to always behave, that the engine always instantly entirely fails within like 30 sec of the slightest anomaly in engine-sound (metal chirping). Would be super awesome if someone with a reallife background regarding radial piston engines can share his experience in here regarding that.

[peachmonkey]

6 minutes ago, D4n said:

I'd guess that the metal-chirping sound in reality can also gradually increase over the course of several minutes, when the engine is only barely stressed beyond limit, and that giving the pilot time to drastically lower the output and get at least 5 or 10 more minutes for a powered landing instead of how it currently seems to always behave, that the engine always instantly entirely fails within like 30 sec of the slightest anomaly in engine-sound (metal chirping). Would be super awesome if someone with a reallife background regarding radial piston engines can share his experience in here regarding that.

undoubtedly, I've experienced what you describe, however I've had plenty of situations where I was able to baby the engine enough to pro-long the flight for another 10-15 minutes desprite the metal chirping/rubbing sounds. Usually I drop the rpm's to ~2,000 and manifold at the ~30".

BUT:
- the initial damage conditions for 'babying' the engine use-cases are mostly (if not all) external (i.e. AA, ground fire, etc).

- when the engine gets overboosted for a prolonged amount of time, when the metal-chirping comes on, a pretty quick engine death follows withing less than a minute.

In other words there's a variance in survivability for the metal-chirping "indicator".

[Brigg]

Yeah as peachmonkey said it depends how the damage occurs, and reducing mp and rpm can extend its life. I have flown back over the channel multiple times with the metal chirping simply dy reducing mp and rpm after being damaged by flak

[D4n]

Afaik it should behave same with internal damage then, and not die within 30 sec if pilot smashes back all levers as soon as the slightest sound anomaly appears, knowing that every second counts... This seems to be a very illogical issue then, unless ED devs can state why it would behave different from external damage than from internal damage. I mean, surely some of you paid the full 50$ price for this module and not the 40$ for WWII project many years ago (from which I received normandy+assets, P-47, Spitfire and Bf-109 for 40$ total), right? Or did you all receive it from that WWII project aswell?

Edited April 14, 2023 by D4n

[303_Kermit]

On 4/2/2023 at 10:49 PM, D4n said:

I had a similar thing, I flew for 30-45 min. multiplayer, with all values in green levels, and shortly using WEP a few times (only seconds, for testing, and not the advertised 15 min.) when suddenly a metal chirping sound started and prop stopped. Could the issue be that water for water-injection is disabled in mission file and that causing huge engine stress within only seconds?

I spend 3 months mastering the Jug. And I had similar problems:
there are 2 main reasons why Double Wasp gets damaged:
-Main rod bearing damage: (occurs while trying to break with an propeller)
to avoid : reduce rpm and boost by moving both levers back together. The steeper the dive is, the more you shall move them back.
-False Ignition: (Too high / too low carb. air temperature, too high manifold pressure)
most of the time when engine gets damaged without obvious reason is when carb.air temp. is below operational range. My suspicion is that it shall simulate an icing of carburetors?
To avoid damage : keep proper temp. and manifold pressure

My best regards
Kermit

[Nealius]

Even with good temps I've found extended overboosting to eventually kill the engine in combat. On one flight I hadn't realized that on hot starts the boost/throttle interconnect is on by default. Flew for a good 25 minutes when I heard my engine knocking at about 55" MP, full prop pitch, with all temps in the blue. It died soon after.

On the next flight I made sure to disconnect the boost/throttle and had no problems.  

Edited May 28, 2023 by Nealius

[grafspee]

6 hours ago, Nealius said:

Even with good temps I've found extended overboosting to eventually kill the engine in combat. On one flight I hadn't realized that on hot starts the boost/throttle interconnect is on by default. Flew for a good 25 minutes when I heard my engine knocking at about 55" MP, full prop pitch, with all temps in the blue. It died soon after.

On the next flight I made sure to disconnect the boost/throttle and had no problems.  

 

If you check temps do you also check carb air temp this one is important as oil temp in P-47 when flying at high power settings.