Engine damage model and leak issues. (Edited title)

[I./JG52_Woutwocampe]

Bump. Add Mig 3 to the list of 'I dont need coolant or oil to function properly'.

 

I saw 2 earlier today leaking both oil and coolant. They still managed to run away at max power and eventually made it to their airfield. I pursued them to finish them while they were landing but I got wrecked by AAA when nearing their airfield. 

[the_emperor]

I would like to bring the thread up for some questions if my own interest. Namely what where coolant capacities/system pressures of the main fighters?

thus far I have

P-51: 16.5 US gallons ~ 63l/ 30psi

Spitfire IX: 14.5 imp gallon~66l / ? Psi

early 109s DB605A: ? Litres / 0.75atü ~ 25psi

late 109s DB605: ? Litres / 1.00atü ~ 28.5psi

Lagg-3: ? / ?

Yak-7/9: ? / ?

Yak-1: ?/?

Hurricane ? / ?

Spitfire V: ? / ?

Edited January 16, 2022 by the_emperor

[I./JG52_Woutwocampe]

Good question @the_emperor, I dont have the data unfortinately. But sometimes if feels that most if the planes have endless supply of coolant and that the cooling system remains pressurized no matter how much damage it took. 

[the_emperor]

Ive read somwhere that the DB605 in the Bf109 only contains ~35litres, which of course would make the radiator cut off vital if you are trying to limp home/over friendly territory with a damaged radiator and two damaged will probably a very fast end for you. on the other hand I dont know how radiator damage is modelled in the game. Is der a diffrerence if my radiator eats a rifle calibre round or a 20mm HE?

[354thFG_Drewm3i-VR]

On 12/30/2021 at 6:12 PM, I./JG52_Woutwocampe said:

Bump. Add Mig 3 to the list of 'I dont need coolant or oil to function properly'.

 

I saw 2 earlier today leaking both oil and coolant. They still managed to run away at max power and eventually made it to their airfield. I pursued them to finish them while they were landing but I got wrecked by AAA when nearing their airfield. 

The beloved 109 is the worst offender BY FAR...and it's not even close.

[I./JG52_Woutwocampe]

I totally disagree about the 109 being the worst. Its the opposite, its the only fighter that will regularily have critical engine failure because of a leak. 

 

Yes I have seen 109's fly for a while with a coolant leaks, but its not always the case like other liquid cooled aicrafts. 

 

 

[354thFG_Drewm3i-VR]

 The fact of the matter is ALL of the liquid cooled engines are WAY too durable and ALL of the radial engines are WAY too fragile. The p-47 should be able to limp back to base down two cylinders. We don't see that in game. A 109 leaking coolant should seize up in 5 minutes tops. 

 

See for yourself around 6:30:

 

Edited January 24, 2022 by -332FG-drewm3i-VR

[I./JG52_Woutwocampe]

Yeah well that is true though. 

[354thFG_Drewm3i-VR]

10 minutes ago, I./JG52_Woutwocampe said:

Yeah well that is true though. 

This issue is systemic and is similar to the far too authoritative low speed, high AoA handling that all but some the newest (Spitfire XIV) planes are not guilty of. The 109, FW 190 A3, and Hurricane are the worst offenders of this IMO. Fly both sides and you'll see what goes on across the board.

[III/JG52_Otto_-I-]

On 10/4/2021 at 3:38 PM, I./JG52_Woutwocampe said:

Some inline engines in this game are too tough but the merlin in the Hurricane is the worst. Since this plane has been introduced I have never seen its engine run out of oil or coolant even after 30 minutes of severe leaks.

The thread title It sound as Luft-whinner claim, ...but the real problem is that Damage Modeling is very poor in all aircrafts in game. I thinks that many virtual pilots here claimed about a more realistic "draining times" for all fluids of the aircraft, such us, water, oil, fuel, and hydraulic systems when they are damaged or punctured. 

 

On 1/16/2022 at 11:11 AM, the_emperor said:

I would like to bring the thread up for some questions if my own interest. Namely what where coolant capacities/system pressures of the main fighters?

thus far I have

P-51: 16.5 US gallons ~ 63l/ 30psi

Spitfire IX: 14.5 imp gallon~66l / ? Psi

early 109s DB605A: ? Litres / 0.75atü ~ 25psi

late 109s DB605: ? Litres / 1.00atü ~ 28.5psi

In reference to in-line piston engines cooling systems of WWII era, we can found several interesting info in the new Calum Douglas book.
Calum refer in his book page: 296, that Germans engine developers studied several captured RR-Merlin´s, they found that british cooling systems were pressurised at 4 atm (about 60 psi) and this reduced the size of the British raditors to a half size, compared with Bf-109 radiators, and working at 125ºC,  (10ºC higther than DB-60X engines).

The reason because Germans didn't used high pressure radiators unlike British Spitfire and Hurricanes is explained in page: 185.
 "A highly pressurised system will drain itself rapidly if damaged by a bullet strike and once the pressure is removed, will begin to boil off at hight altitude extremely rapidly. The German system was designed to be robust as possible at the cost of reduced cooling efficiency, a fact which was beginning to infuriate  Professor Messerschmitt who wanted to make his radiator system smaller but could not."  
We have not these differences modelled in game and casually it is affecting negatively to German airplanes.
 

Edited January 24, 2022 by III/JG52_Otto_-I-

[I./JG52_Woutwocampe]

Interesting. 

[Dakpilot]

12 hours ago, -332FG-drewm3i-VR said:

The p-47 should be able to limp back to base down two cylinders. We don't see that in game.

 

Perhaps "should" would be better replaced with "could" and applies to most radials  generally rather than just the R2800 in the P-47, B-17's with the Wright 1820 and BMW 801 etc. etc. are also reported 

I would hazard (an educated) guess that this actual occurrence is much rarer than people think and much more of an outlier than the norm.. 

 

Cheers, Dakpilot 

[Eisenfaustus]

16 minutes ago, Dakpilot said:

 

Perhaps "should" would be better replaced with "could" and applies to most radials  generally rather than just the R2800 in the P-47, B-17's with the Wright 1820 and BMW 801 etc. etc. are also reported 

I would hazard (an educated) guess that this actual occurrence is much rarer than people think and much more of an outlier than the norm.. 

 

Cheers, Dakpilot 

But not because the cylinders are destroyed but because the same burst might have caused additional damage that kills the plane. 
Air cooled radials absolutely should bring you home if the only serious damage are two cylinders missing. 

[Dakpilot]

3 hours ago, Eisenfaustus said:

Air cooled radials absolutely should bring you home if the only serious damage are two cylinders missing. 

 

Every time? 

 

Cheers, Dakpilot 

[DD_Arthur]

4 hours ago, Eisenfaustus said:

Air cooled radials absolutely should bring you home if the only serious damage are two cylinders missing. 

 

Sorry but that is absolute nonsense.

[ACG_Cass]

Only thing stopping a radial is if it runs out of oil, the damage is severe enough to seize the engine or you hit one of the few parts that are vital for the engine to function as a whole.

 

2 out of 18 cylinders not working isn't going to be an issue.

 

[the_emperor]

18 hours ago, III/JG52_Otto_-I- said:

Calum refer in his book page: 296, that Germans engine developers studied several captured RR-Merlin´s, they found that british cooling systems were pressurised at 4 atm (about 60 psi)

60psi? holly cow, that is a fraking lot. Are there any documents. I found only 30psi in secondary scources.

[Zanzibar]

For those questioning the ability of a radial to lose cylinders and keep running:

 

From Historical Perspectives on Vulnerability/Lethality Analysis

https://apps.dtic.mil/sti/pdfs/ADA361816.pdf

[I./JG52_Woutwocampe]

I have seen many engines leak oil for more than 20 minutes without seizing in GB.

 

In fact I have seen many liquid cooled engine leak both oil and coolant for more than 20 minutes. And they fought during those 20 minutes, used combat and emergency power. 

 

I hope the devs read this topic and that improvements of the engines damage model are on the menu.

 

 

 

 

[III/JG52_Otto_-I-]

3 hours ago, the_emperor said:

60psi? holly cow, that is a fraking lot. Are there any documents. I found only 30psi in secondary scources.

You can read it in the book 

[the_emperor]

15 hours ago, III/JG52_Otto_-I- said:

You can read it in the book 

I really dont want to discredit the author as there seems to have been gone a lot of work into this book.

and maybe the germans did something wrong,

but the Merlin manual says the coolant System is tested for 30psi, the Oil system for 60psi.

and the 30psi are not that much (but still) higher than the 0.75atü/1.00atü of the DB605 series

But none the less, both system are highly pressurized and damage should immediately dregrade cooling perfomance and a sudden loss of fluid.

The 109, can prevent this, by cutting off a damaged radiator, but if both are hit, one should probably throttle back und look for a nice field to ditch or jump.

 

Cheers

Edited January 26, 2022 by the_emperor

[Roland_HUNter]

21 minutes ago, the_emperor said:

I really dont want to discredit the author as there seems to have been gone a lot of work into this book.

but maybe the germans did something wrong,

but the Merlin manual says the coolant System is tested for 30psi, the Oil system for 60psi.

and the 30psi are not that much higher than the 0.75atü/1.00atü.

But none the less, both system are highly pressurized and damage should immediately dregrade cooling perfomance and a sudden loss of fluid.

The 109, can prevent this, by cutting off a damaged radiator, but if both are hit, one should probably throttle back und look for a nice field to ditch or jump.

 

Cheers

Only the early F models and the K-4 had that kind of cutting off system.

[Dakpilot]

Perhaps there is some confusion in terminology.. Are people referring to 'missing' cylinders or cylinders being 'out' meaning not working/firing

 

or actual cylinders being blown off and actually departed from the engine leaving the con rod thrashing about and a big hole? 

 

Cheers, Dakpilot 

[the_emperor]

29 minutes ago, Roland_HUNter said:

Only the early F models and the K-4 had that kind of cutting off system.

IRCC the cut of system was standard with the introduction of the G-series

It can even be seen in the cockpits in the game those green thingis to pull left and right on the cockpit floor.

From the G-2 manual No.20 Kühlerabschaltung, one each left and right:

 

 

 

Edited January 25, 2022 by the_emperor

[Roland_HUNter]

If that green things are the cutoffs, where is it from the K-4?

Ah, it's not in the game:
https://www.airgoons.com/w/File:Bf109-Pit.jpg

https://forums.ubisoft.com/showthread.php/92717-Request-to-Oleg-Radiator-cut-off-valve-for-Bf-109-F-G-K

[III/JG52_Otto_-I-]

2 hours ago, Roland_HUNter said:

Only the early F models and the K-4 had that kind of cutting off system.

In according with the G-2 Flugzeug-Handbuch (aircraft manual) it was equipped with cooling shut-off valves



As far as I know G-1 was not equipped with these radiator shut-off valves from factory, but quickly the field mechanics cannibalised them from other non-serviceable Bf-109F, who had these valves. G-2 series onward all types had these radiator shut-off valves from factory.

 

Edited January 25, 2022 by III/JG52_Otto_-I-

[the_emperor]

I am not quite sure, bit didnt the Spitfire starting with the Merlin 6X series did also have the ability to cut off the left or right radiator?

[Roland_HUNter]

20 hours ago, III/JG52_Otto_-I- said:

In according with the G-2 Flugzeug-Handbuch (aircraft manual) it was equipped with cooling shut-off valves



As far as I know G-1 was not equipped with these radiator shut-off valves from factory, but quickly the field mechanics cannibalised them from other non-serviceable Bf-109F, who had these valves. G-2 series onward all types had these radiator shut-off valves from factory.

 

Hmmm, so Jochen Prien (Author), Peter Rodeike (Author), David Johnston (Translator) were wrong? ?

[the_emperor]

1 hour ago, Roland_HUNter said:

Hmmm, so Jochen Prien (Author), Peter Rodeike (Author), David Johnston (Translator) were wrong? ?

 

yes, that happens. Better double check the main scources and manuals. Books and articles about WWII aircombat and planes are generelly not up to a scientific standard and are mostly products to entertain (as manuals  and reports are often quite boring).

Anyone can publish them and there is often no peer review as it is a very niche thematic. But thanks to the forum you have access to many main scources and knowledge (which are then of course up for discussion ? )

 

Edited January 26, 2022 by the_emperor

[I./JG52_Woutwocampe]

I might just be a coincidence but lately I have see my share of P-40 engines seizing or losing significant power quite quickly after suffering from an oil leak.

[I./JG52_Woutwocampe]

The Pe-2 is officially the aircraft that cares the less about leaks. Their engines will simply never stop. 

 

 

[I./JG52_Woutwocampe]

The IL2's weak spot was the big belly radiator, thats a well known fact right?

 

Well not in GB as even if you damage it, the IL2s will keep going forever and land safely eventually. 

 

I cant remember the last time I have seen a IL2 engine fail because of a damaged belly radiator.

 

Edit : yesterday in my 110 career (Stalingrad) arose the perfect opportunity to test oil leaks for the IL2 when the belly rad is damaged.

 

Ok, there was 6 of them, unescorted, on their way to their target, I crossed them while coming back from an successful escort mission myself. I had around 130 rounds of 20mm left.

 

I quickly damage the radiator of the first but also inflicted significant damage to the whole plane. So I left it alone and targeted the others. Soon enough, I had 5 out of the 6 IL2s leaking oil, including one with a HUGE leak, probably the thickest brown trail you can get in this game.

 

The first one crashes quickly, I have no clue how. I will assume its because of the extensive damage here. So we have 4 IL2s left with rad damaged and one without any damage. To my surprise, only one of the damaged IL2s turned back to head home. The other 4, 3 damaged and one ok continued towards their target! So I decided to follow them. I was out of ammo at this point.

 

All 4 reached target withing 10 minutes. Of course the 3 damaged IL2s had their windshields completely covered in oil but that didnt prevent the AI from being extremely accurate with their rockets.

 

After like 5 minutes, they stopped their grpund attack but instead of going home....they started to circle above the target forever. Note that its been 15 minutes or more of oil leak including the one with the massive oil leak. 

 

Its been another 10/15 minutes until finally the engine of the massive oil leak IL2 finally started to lose power so much that it stalled and crashed. Lets say that overall he flew for almost 30 minutes with this massive leak. The two others flew for another 15-20 minutes before losing power. Believe it or not, I was myself starting to run low on fuel, in a 110! 

 

So, another display of leaks taking way too long to affect the engine and cause issues. If the IL2s would not have gone stupid and hover above target, at least 2 of them would have made it back home.

Edited March 31, 2022 by I./JG52_Woutwocampe

[I./JG52_Woutwocampe]

Im bumping this topic because unfortunately no improvement has been made over the engines dm and still, up to this date, liquid cooled engines are too tough.

Edited September 27, 2022 by I./JG52_Woutwocampe

[354thFG_Drewm3i-VR]

Just now, I./JG52_Woutwocampe said:

Im bumping this topic because unfortunately no improvements have been made over the engines dm and still, up to this date, liquid cooled engines are too tough.

For what its worth, I killed someone in a 109 the other day on Combat Box by stopping his engine after streaming coolant for only a few minutes. No fire or pilot kill.

[I./JG52_Woutwocampe]

1 hour ago, drewm3i-VR said:

For what its worth, I killed someone in a 109 the other day on Combat Box by stopping his engine after streaming coolant for only a few minutes. No fire or pilot kill.

 

The 109 is the liquid cooled aircraft with the most realistic engine damage model imo. Its vulnerable, and often, the engine will quickly lose significant power if leaking coolant, or seize if there's a significant oil leak.

 

Other aircrafts though, Merlin powered, Klimov powered, will give the finger to any leak and remain inflight operating at combat power for absurd amounts of time without the engine suffering from it. 

 

I decided to bump this topic because yesterday I saw a Yak 1 go on forever with both a coolant and an oil leak. And I thought the AI was supposed to abandon fight and go back home if leaking? This guy fought for a while, I mean A WHILE with both leaks and then went home, at full speed so I could not catch it with my 110. Until I told myself screw it, turned back and went home too. He eventually despawned. It remained airborne with both leaks for 30 minutes or more including a good part in combat. No way in HELL its engine would have remained at peak efficiency or close to it for this long.

 

And appart from the 109 its always like that with inline engines. Hurricane, MiG, Pe2, name it.

 

Leaks are irrelevant. Not realistic.

[the_emperor]

I havent done any tests on that topic but my P51 with a radiator leak didnt make it even half over the channel (Calais->Dover); that felt quite right.

I guess the channel is a measurement and no liquid cooled engine should be able to cross that when damaged (from my feelings, no scientific test)

[357th_KW]

That’s been my experience as well so far - the only guy I’ve shot up and seen limp back to base leaking coolant was nearly over his own coast at fairly high altitude when I hit him.

[357th_KW]

To add to this, last night I was in a Hurricane and got hit by 12 x 8mm rounds, damaging my engine and causing a radiator and oil leak.  Even with the engine pulled well back and the radiators full open I only made it 20km before the engine quit and I had to bail - 4 minutes or so at best.

[I./JG52_Woutwocampe]

12 hours ago, 357th_KW said:

To add to this, last night I was in a Hurricane and got hit by 12 x 8mm rounds, damaging my engine and causing a radiator and oil leak.  Even with the engine pulled well back and the radiators full open I only made it 20km before the engine quit and I had to bail - 4 minutes or so at best.

 

Well you are 'lucky' I guess. Yesterday I made it back home in an Mc202 with a coolant leak. About 40 km's, and close to 1.3 ata for the entire run. 

[I./JG52_Woutwocampe]

So, a few days ago a Spit mark IX crossed the entire channel with a thick oil leak from the left wing's rad.

 

He got this leak while fighting above France so I assume it was a full 60 minutes bleeding oil significantly. He finally crashed just after reaching England.

 

I would assume such a thick brown leak would make the engine seize much faster.