Mechanics of engine timers

[Charon]

This isn't a thread to discuss the realism of engine timers, or real world engines. That's been done to death.

 

Rather, I'd like to understand how it's implemented, as a game mechanic. Who has tested the limits? Do we have answers to these questions?

 

I've read that some engines "recharge" faster or slower than others, but I can't remember where I read this. Is it true? How long should I rest my engine after using combat power?

 

I've found that I can run engines on combat or emergency power slightly longer than their nominal rated times. Is there some consistent multiplier here? Can I run engines to 110% of their rated time without issue, or does this carry a chance of failure? Does running engines beyond their rated time cause any permanent harm even before techchat warns of engine damage?

 

How much do I stretch my timer by running at a reduced combat power setting? If I'm flying a 109G-6 (30 minutes @ 1.3ATA), how much longer can I run 1.2ATA?

 

How do multiple limits stack? Do they run concurrently? Consecutively? Proportionally? For example, if I'm flying a 109 G-6 (30 minutes @1.3ATA, 1 minute @ 1.42ATA) and I run for 1 minute at 1.42 ATA, how long can I subsequently run at 1.3? Is it:

 

• 0 minutes, because I've used 100% of my 'engine timer budget',
• 29 minutes, because I've already been above 1.3 for 1 minute.
• 30 minutes, because running 1.42 consumes my 'emergency budget', and 1.3 draws from a separate 'combat budget'

 

Does my Emergency budget "recharge" while on combat power, or do I need to drop to cruise settings to recharge (presumably MW-50 and water injection never recharges).

 

I'll run some tests myself if I have to, but I figured I'd ask for prior art first.

[PaladinX]

It stays a game (and not a simulation) until this ridiculous, not comprehensible timing mechanics is thrown out of the game.

[AEthelraedUnraed]

1 hour ago, Charon said:

I've found that I can run engines on combat or emergency power slightly longer than their nominal rated times. Is there some consistent multiplier here? Can I run engines to 110% of their rated time without issue, or does this carry a chance of failure? Does running engines beyond their rated time cause any permanent harm even before techchat warns of engine damage?

I can't remember who exactly but someone did a number of tests. It turned out that the timer at the extreme end of a certain power setting equals the time in the manual. E.g. if the manual says:

- cruise, 1.1 ATA, infinite time,

- combat, 1.2 ATA, 10 minutes,

- emergency, 1.3 ATA, 2 minutes,

then if you put the throttle at 1.299 ATA, i.e. *just* below emergency, you have 10 minutes + a random timer until your engine fails. If you move your throttle just a little bit forward to 1.301 ATA, it'll be 9.99 (+ random) minutes or something. If you put the throttle all the way forward to 100%, it's two minutes (again add a couple of randomly awarded seconds). There's no way of knowing how much random time is awarded, but as long as you don't exceed it, there won't be any damage.

Edited September 10, 2022 by AEthelraedUnraed

[Youtch]

I am under the impression that those timers recharge, if you put throttle down. Do they all recharge and how long do they take to recharge?

[CountZero]

2 hours ago, Charon said:

This isn't a thread to discuss the realism of engine timers, or real world engines. That's been done to death.

 

Rather, I'd like to understand how it's implemented, as a game mechanic. Who has tested the limits? Do we have answers to these questions?

 

I've read that some engines "recharge" faster or slower than others, but I can't remember where I read this. Is it true? How long should I rest my engine after using combat power?

 

I've found that I can run engines on combat or emergency power slightly longer than their nominal rated times. Is there some consistent multiplier here? Can I run engines to 110% of their rated time without issue, or does this carry a chance of failure? Does running engines beyond their rated time cause any permanent harm even before techchat warns of engine damage?

 

How much do I stretch my timer by running at a reduced combat power setting? If I'm flying a 109G-6 (30 minutes @ 1.3ATA), how much longer can I run 1.2ATA?

 

How do multiple limits stack? Do they run concurrently? Consecutively? Proportionally? For example, if I'm flying a 109 G-6 (30 minutes @1.3ATA, 1 minute @ 1.42ATA) and I run for 1 minute at 1.42 ATA, how long can I subsequently run at 1.3? Is it:

 

• 0 minutes, because I've used 100% of my 'engine timer budget',
• 29 minutes, because I've already been above 1.3 for 1 minute.
• 30 minutes, because running 1.42 consumes my 'emergency budget', and 1.3 draws from a separate 'combat budget'

 

Does my Emergency budget "recharge" while on combat power, or do I need to drop to cruise settings to recharge (presumably MW-50 and water injection never recharges).

 

I'll run some tests myself if I have to, but I figured I'd ask for prior art first.

For 109G6 spec say:
Engine modes:

Nominal (unlimited time): 2300 RPM, 1.15 ata
Combat power (up to 30 minutes): 2600 RPM, 1.3 ata
Emergency power (up to 1 minute): 2800 RPM, 1.42 ata

 

So if you in game realisam turn on instrument panel and Techchat youll be able to finaly see broken mesages that tell you when exactly game engine timer expire or recover, so then you can test how they work.

If you use 2800rpm and 1.42 ata youll get message that timer expired at 1min , and then if you fly on combat OR continuous for 13min youll get message that your emergancy recovered.

To fully recover 1min you waisted you need 13min of flying on any mode then emergancy, and it doesent mather what mode, it dont charg faster its always same time.

Going abow 1 min emergancy you are in random fail time, sometimes you can push it 1-2min abow when you got message it expired, and other times it will brake even after 10s abow message.

Regarding recharg you dont have to wait untill its fully recharged, you can use it but it will last shorter as its not fully recharged, if you wait 13s you get 1s, for example like this, if you used up 1min and then fly 5min on combat you can then use again 23s of emergancy and then message that your timer expired will show up.

Using emergancy 1 min will waist 1 min of combat, so youll have 29min after using 1min.
Recharg time is same for combat and emergancy, so when you used up 30 min of combat you would have to wait/ fly on continuous for 30x13=390min, so youll never fully recharg combat timer after you used it up. So you can recharg it gradualy, if you totaly used up combat , 13min of continuous will get you 1min of combat back, so after 13min you can fly on combat 1min.

 

MW50 also needs to be recharged, but its recharg is 1:1, so using 10min of it will take flying 10min on combat to recharg it fully, and it dosent eat up combat timer, like emergancy do.
After you waist MW50 liquid, you cant use it again.

 

Flying below 2800rm, OR 1.42 ata will extend emergancy timer, for how long who knows. So if 2600rpm and 1.3 ata is 30min, andd 2800rpm and 1.4 ata is 1min, flying betwen thouse two setings is some time betwen 30 and 1 min. So if you fly at alt abow critical, where your engine at 100% cant get you 1.42 ata you will have longer emergancy timer, you can do 2800rpm but if you do only 1.35ata at 100% power, your safe emergancy timer will be extended more then 1min.

 

Also techchat % at what time icon say your in combat mode (83% say combat mode, but your at 1.32 ata, you would think its not mutch abow 1.3 but you lost 10min from 30min if you fly 83% insted 80% that is real max combat mode) will trick you as at valuse abow 2600rpm or 1.3 ata it will tell you your in combat mode, but your already abow so your using timer mutch faster and youll run out of timer at 20min for example insted 30min.

 

flying longer in random fail mode dont damage your engine for later use, your just risking kiling engine as you dont know when timer will get it. So risking and flying 2min insted 1min emergancy, have no effect on your engine after.

 

For 109s its simple compared to how it works on some american airplanes...
 

Edited September 10, 2022 by CountZero

[Youtch]

1 hour ago, CountZero said:

After you waist MW50 liquid, you cant use it again

How many recharge MW50 liquid can sustain?

[=X51=VC_]

This is a good question and some good replies as well.

 

For me, the most important part that hasn't been answered fully is how long you can stay at intermediate settings. For example I have a squad mate that says you can fly the 109G-4 at 90% throttle for 5 min safely. I don't kow what RPM/ata this converts to, I guess about 1.35 ata, but this is still an anecdote.

 

There are more interesting planes to try this with anyway, for example the Spitfire IX with very long (1 hour) but quite weak combat power and 5 min emergency. I would like to see if for example you can run it for 15 min at 3,000 rpm and +15 psi boost, which is the combat power setting on the P-51D that is using functionally the same engine.

 

 

23 hours ago, PaladinX said:

It stays a game (and not a simulation) until this ridiculous, not comprehensible timing mechanics is thrown out of the game.

 

I agree with this in principle... BUT... how do you propose to stop everyone just flying at max emergency setting from the second they take off to the second they land, without some artificial limit?

Edited September 11, 2022 by =X51=VC_

[PaladinX]

8 hours ago, =X51=VC_ said:

This is a good question and some good replies as well.

 

For me, the most important part that hasn't been answered fully is how long you can stay at intermediate settings. For example I have a squad mate that says you can fly the 109G-4 at 90% throttle for 5 min safely. I don't kow what RPM/ata this converts to, I guess about 1.35 ata, but this is still an anecdote.

 

There are more interesting planes to try this with anyway, for example the Spitfire IX with very long (1 hour) but quite weak combat power and 5 min emergency. I would like to see if for example you can run it for 15 min at 3,000 rpm and +15 psi boost, which is the combat power setting on the P-51D that is using functionally the same engine.

 

 

 

I agree with this in principle... BUT... how do you propose to stop everyone just flying at max emergency setting from the second they take off to the second they land, without some artificial limit?

 

Like you would do in reality: Watch your temperature, work with the cooling systems in the specific aircraft, and risk a full blown motor when you stay on emergency...without a timer.

[CountZero]

On 9/10/2022 at 1:59 PM, Youtch said:

How many recharge MW50 liquid can sustain?

it can last 25min in total, how you use it its up to you and your fuel supply.

 

10min emry+mw50 then 10min combat then 10min emergy+mw50 then 10min combat and then 5min emergy mw50 if you still have fuel left.

11 hours ago, =X51=VC_ said:

This is a good question and some good replies as well.

 

For me, the most important part that hasn't been answered fully is how long you can stay at intermediate settings. For example I have a squad mate that says you can fly the 109G-4 at 90% throttle for 5 min safely. I don't kow what RPM/ata this converts to, I guess about 1.35 ata, but this is still an anecdote.

 

There are more interesting planes to try this with anyway, for example the Spitfire IX with very long (1 hour) but quite weak combat power and 5 min emergency. I would like to see if for example you can run it for 15 min at 3,000 rpm and +15 psi boost, which is the combat power setting on the P-51D that is using functionally the same engine.

 

 

 

I agree with this in principle... BUT... how do you propose to stop everyone just flying at max emergency setting from the second they take off to the second they land, without some artificial limit?

try clod and see how its done without timers, in clod i had to look in cokpit gauges and i had to lisen to engine, in box i just look at techchat (every server have them so no point flying without like in clod) and avoid airplanes with more then 1 short timer as how its now with messages being buged when only techchat is on, your flying airplanes with random engine fail if you fly airplanes with multiple short timers. In SP i just turn on undestructable and then timers dont work, its bliss.

Edited September 11, 2022 by CountZero

[=MERCS=JenkemJunkie]

The answers to all your questions will vary plane by plane. Theres no easy universal rules to timers and recharge times. You'll have to individually test all these numbers for every plane you want to know these numbers too. The more you learn about the timers, the more you'll hate them.

[the_emperor]

12 hours ago, =X51=VC_ said:

I agree with this in principle... BUT... how do you propose to stop everyone just flying at max emergency setting from the second they take off to the second they land, without some artificial limit?

 

 In principle if an engine is cleared for a certain power setting, you can run it as long of you have fuel/water injection, your temperatures (oil/water/cylinder), Oil Pressure  are in the green. 

Because we dont have to worry about engine service life (the reason why those time limits are in the manuals and its said so in those manuals)  as we always get a brand new airplane/engine  and dont have to worry to get in trouble with the quartermaster about an worn out engine. and our missions are so short, we dont have to care for fuel consumption.

So as @CountZero said,  CloD did it right in that regard.

 

Edited September 11, 2022 by the_emperor

[=X51=VC_]

Right, let me get this thread back on topic. I guess if you want something done you have to do it yourself, so I did. I tested a few planes at intermediate engine settings, here are my findings so far:

 

@Charon

 

All tests are on Kuban Autumn at 1,000m altitude. Engine temperature limits were never exceeded during any test.

 

Bf 109G-4 (applies to G-6, G-6 late, and probably F-4 too) - 3 flights, power settings and time to engine damage:

 

2,700 RPM ~1.37 ata - 9 minutes
2,700 RPM ~1.37 ata - 12 minutes
2,700 RPM ~1.37 ata - 8 minutes

 

Fw 190A-8 (should apply to all Antons) -  single check flight, similar to 109 findings:

2,550 RPM lasted for 15 minutes. This is exactly halfway between 2400 combat RPM and 2700 max RPM. I didn't use the special boost.

 

 

Spitfire Mk.IXe - initial 3 flights, power settings and time to engine damage:

 

3,000 RPM +15 lbs boost - 11 minutes
3,000 RPM +15 lbs boost - 12 minutes
3,000 RPM +16 lbs boost - 11 minutes

 

then this one got really interesting once I started playing with the RPM.

 

2,900 RPM +15 lbs boost - stopped test after 30 minutes no failure
2,900 RPM +16 lbs boost - 25 minutes
2,900 RPM +18 lbs boost - 15 minutes

 

Spitfire Mk.XIV - singe test flight to confirm the above:

 

2,650 RPM +15 lbs boost - 19 minutes

 

 

P-51 - 3 flights, power settings and time to engine damage - tested in the B so I turned the boost on and then throttled back a bit to get 64", but the D has the same engine:

 

3,000 RPM 64" Hg - 15 minutes
2,850 RPM 67" Hg - 7 minutes
2,850 RPM 64" Hg - 25 minutes

 

 

Tentative conclusions:

 

• you can abuse engines for way longer than the stated timer with a relatively small power setting decrease
• RPM seems to be the bigger factor in the engine failure timings
• the benefit seems greater the larger the difference between the combat and emergency timers
• the Spitfire is super abusable in this way, probably because of the 1 hour combat timer

 

If anyone else has time to test some more planes, or just get some more data on the same planes, I'm sure we can make this a really useful thread ?

 

[Mtnbiker1998]

Definitely curious to see what numbers show up for the P-40 and P-39. They're some of the worst victims of the timers.

[Traffic]

P40, by far is the absolute worst. Cant give it any beans and it cooks within 8 seconds. Combat time, 15ish minutes, but immediately goes to engine damage. If the engine in the P40 was usable, it would/could be a contending aircraft. I find it to be an incredibly stable gun platform, but you basically have to run everything in continuous, which obviously doesnt work in combat. The P39 is far better. Its been beat to death though. The P40 is VERY underrepresented here, and everyone knows it. Beating a dead horse....

 

[=X51=VC_]

I haven't had time to test more, but I don't think the P-40 will benefit much, in the same way the P-51 doesn't really benefit.

 

This is because their combat and emergency settings are already quite close together in terms of both power setting and timers, and, crucially, they have same RPM for combat and emergency.

 

You lose some power from lower RPM. So if both RPM and manifold pressure are between settings, you get intermediate power for longer duration and that's a good compromise. But if you get e.g. +3" HG for -100 RPM this might not be a clear benefit.

 

So for the P-40 you could probably squeeze 10 minutes at 2,850 RPM and 43" or something, that would be my test condition, but it might not be worth it. Maybe you can spend 20 minutes trying it yourself, it's not that hard ?

 

The bigger issue with the P-40 is the lack of regulator means you either accidentally eat more timer than you expected, or you always run at reduced settings to be safe. It's just harder work optimising it.

Edited September 14, 2022 by =X51=VC_

[Knarley-Bob]

It would sure be nice if all one had to do is drive slow to get a recharged motor. BOTH my wife & my cars could use it .?

I have an old motorcycle that could use it too.

Timers are not real, and have no place IMHO.

Some industrial motors have "timers" but they go into 1000's of hours as on a forklift or tractor motor.

A "timer" for a single mission?  Hogwash

Edited September 14, 2022 by Knarley-Bob

[FeuerFliegen]

On 9/12/2022 at 5:25 PM, =X51=VC_ said:

Right, let me get this thread back on topic. I guess if you want something done you have to do it yourself, so I did. I tested a few planes at intermediate engine settings, here are my findings so far:

 

@Charon

 

All tests are on Kuban Autumn at 1,000m altitude. Engine temperature limits were never exceeded during any test.

 

Bf 109G-4 (applies to G-6, G-6 late, and probably F-4 too) - 3 flights, power settings and time to engine damage:

 

2,700 RPM ~1.37 ata - 9 minutes
2,700 RPM ~1.37 ata - 12 minutes
2,700 RPM ~1.37 ata - 8 minutes

 

Fw 190A-8 (should apply to all Antons) -  single check flight, similar to 109 findings:

2,550 RPM lasted for 15 minutes. This is exactly halfway between 2400 combat RPM and 2700 max RPM. I didn't use the special boost.

 

 

Spitfire Mk.IXe - initial 3 flights, power settings and time to engine damage:

 

3,000 RPM +15 lbs boost - 11 minutes
3,000 RPM +15 lbs boost - 12 minutes
3,000 RPM +16 lbs boost - 11 minutes

 

then this one got really interesting once I started playing with the RPM.

 

2,900 RPM +15 lbs boost - stopped test after 30 minutes no failure
2,900 RPM +16 lbs boost - 25 minutes
2,900 RPM +18 lbs boost - 15 minutes

 

Spitfire Mk.XIV - singe test flight to confirm the above:

 

2,650 RPM +15 lbs boost - 19 minutes

 

 

P-51 - 3 flights, power settings and time to engine damage - tested in the B so I turned the boost on and then throttled back a bit to get 64", but the D has the same engine:

 

3,000 RPM 64" Hg - 15 minutes
2,850 RPM 67" Hg - 7 minutes
2,850 RPM 64" Hg - 25 minutes

 

 

Tentative conclusions:

 

• you can abuse engines for way longer than the stated timer with a relatively small power setting decrease
• RPM seems to be the bigger factor in the engine failure timings
• the benefit seems greater the larger the difference between the combat and emergency timers
• the Spitfire is super abusable in this way, probably because of the 1 hour combat timer

 

If anyone else has time to test some more planes, or just get some more data on the same planes, I'm sure we can make this a really useful thread ?

 

 

When you post these tests,  you need to stop your testing the second technochat states that your emergency/combat/etc. has been exceeded, and NOT when the engine actually takes damage.  This way the tests will be consistent, as the engine taking damage is simply a random chance after the timer runs out and doesn't really give us any useful information to go by.

 

I've done these same tests several times in the past myself; I'll post up some of my data here sometime.

 

 

On 9/10/2022 at 6:40 AM, CountZero said:

Recharg time is same for combat and emergancy, so when you used up 30 min of combat you would have to wait/ fly on continuous for 30x13=390min, so youll never fully recharg combat timer after you used it up. So you can recharg it gradualy, if you totaly used up combat , 13min of continuous will get you 1min of combat back, so after 13min you can fly on combat 1min.

 

This is not correct; I have tested this on many different planes.  Combat timers typically are around 1:1 or 2:1, depending on the plane.

Edited January 15, 2023 by SCG_FeuerFliegen

[Dragon1-1]

On 9/11/2022 at 10:18 AM, =X51=VC_ said:

I agree with this in principle... BUT... how do you propose to stop everyone just flying at max emergency setting from the second they take off to the second they land, without some artificial limit?

You don't. The Soviets did, in fact, flew around in WEP most of the time. This is the only way to get historically accurate performance out of the P-40 and P-39, as far as Soviet accounts are concerned. On some aircraft, doing that will cook your engine even with radiators set to full open (engine overheat mechanics are there already), and for the Germans MW50 and GM1 limits will still apply since they inject stuff into the engine that runs out after a while. However, this should be based on factors such as altitude, airspeed and the weather. Our missions are too short for engine damage to be a realistic concern. It would cause logistical headaches, but then, this was exactly the case in the war, the engines wore out. During the war, they didn't bother with manual limitations like we have to, they used as much WEP as they needed to stay alive. We should be able to do that, too.

[[CPT]Crunch]

On 9/12/2022 at 10:22 PM, Mtnbiker1998 said:

Definitely curious to see what numbers show up for the P-40 and P-39. They're some of the worst victims of the timers.

True, but they're also the worst for flap abuse, you can drop full flap in a P-39 in a 1G dive at 360 indicated and suffer no problem, in reality the flaps were limited to 140 IAS, all the flap down testing performance charts also have the gear down and the data points end at 140, there is zero flap only tests that I'm aware of.  Not even purpose built flaps for combat like the P-51 or the Lightning can do that in game.

 

On the 39's gear was required to be lowered before flaps, no more than 1/4 flap was allowed for any emergency short field take off, it was recommended only experienced pilots use them when taking off.  With flaps down it had nose authority problems, became wobbly with a nose up attitude.  Not so in game, it's rock solid as a gun platform at high alpha as long as the flaps are dropped. 

 

But than most planes seem to change flight models with flaps down, just not as severe as some of these early planes.  With a 39 you can get effective flight control all the way down to 14 IAS and keep nose straight up as long as flaps are down, which puts it in a helicopter category.  With that kind of enhancement you don't really need all that speed to win a fight, so not such victims after all.  If you were to add more power for longer this plane will hold it's own and even dominate in late 44 west front sets.  We don't really need more of that.  Keep them out, many of the early planes are really freaks, they need more than just timers adjusted.  

 

Edited January 16, 2023 by [CPT]Crunch

[Dragon1-1]

That is a separate thing that needs to be fixed. In particular, IL-2 doesn't model neither flaps nor cowl flap damage from overspeed. On most planes, putting things out into the airstream that aren't dedicated speedbrakes is severely limited. Soviet birds with pneumatic flaps don't really care, because airflow will fold them up if the pilot forgets, but on anything with an actuator, various thing can break, get bent or otherwise messed up if you overspeed the flaps.

 

In fact, Il-2 needs a serious rework of low speed handling. Right now, compared to, say, DCS, landing and takeoff seems downright dumbed down. No doubt the fudging to make that easy is impacting low speed handling in combat, particularly with early aircraft that would otherwise be hard to land.