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-   -   engine oil and radiator damage. Fails too quickly! (http://forum.fulqrumpublishing.com/showthread.php?t=36275)

FFCW_Urizen 12-01-2012 04:59 PM

Quote:

Originally Posted by SlipBall (Post 484913)
Well at least I can make across with the before, the now, is impossible under most conditions.

I glided more than once from Dunkerque towards Hawkinge, it just depends on your altitude ;) . So from now on, no more tree hugging, get up there and play with the big boys :D .

Anders_And 12-01-2012 05:04 PM

Quote:

Originally Posted by FFCW_Urizen (Post 484936)
I glided more than once from Dunkerque towards Hawkinge, it just depends on your altitude ;) . So from now on, no more tree hugging, get up there and play with the big boys :D .

Hehe im seldom below 3000m
But we are not talking about gliding.. We are talking about being able to nurse the engine back home sometimes.. like. Ww2 stories tell us...

*Buzzsaw* 12-01-2012 05:05 PM

Salute

In fact, current aircraft can still fly around far too long and maneuver far too long with leaking radiators.

According to WWII pilots I have read, once their radiators were perforated, they had a maximum of 5 minutes after a leak to either put the aircraft down, or bailout. And it the hole was bigger, the time could be as little as 30 seconds.

109's had a provision to shut one leaking radiator and run the engine off a single, but that was contingent on reducing boost and rpm, it was not possible to run combat power on a single rad without overheating the engine.

I think the current modelling is closer to fact than the previous, which saw aircraft being able to fly around for lengthy periods with leaks. That was not realistic at all.

SlipBall 12-01-2012 05:07 PM

Quote:

Originally Posted by FFCW_Urizen (Post 484936)
I glided more than once from Dunkerque towards Hawkinge, it just depends on your altitude ;) . So from now on, no more tree hugging, get up there and play with the big boys :D .


Height is life:)

SlipBall 12-01-2012 05:13 PM

Quote:

Originally Posted by ATAG_Bliss (Post 484935)
Just wanted to add what's been said by swiss.

Coolant is there simply to maintain an operating temperature for good combustion. To put into perspective, gasoline (oil based) combustion is around 4000 degrees (2100-2200C). This is the temperature inside the cylinder every single time that particular cylinder fires with fuel. In very simple terms, coolant is circulated from the radiator and then to the engine and back again. The thermostat controls this flow of coolant. The coolant in the engine reaches temperature (say 210F) then the thermostat opens allowing for the coolant that has been sitting in the radiator (cooled by air passing through it) to then go into the engine again, while the hot stuff sits in the radiator. Depending on the application / temperature / load on the engine, this process could take place at a constant dribble (constant recirculation of coolant from the engine to the radiator) or it could happen several times a minute (t-stat opening and closing).

The second you don't have coolant to replace the hot stuff in the engine you're gonna have some major problems. If anyone remembers good old carbs, we used to have choke horns, idle bleeds, metering plates, high speed air bleeds, etc.. With the choke on (engine cold) we are restricting air into the engine. This is creating a rich situation (excess fuel). But the engine needs this fuel to run with a low temperature cylinder.

With that said, imagine you have a perfectly running engine (cylinder temperature is on the money, choke is not being used etc.) Just imagine what happens when air temperature in the cylinder is too hot. Remember, when it's cold, we need an excess amount of fuel and less air to keep the engine even running. But we know this when starting the engine. We pull the choke cable and get the ol girl fired up. But when the cylinders creep up in temp (over normal) from a coolant loss, we are still pumping the same amount of air, same amount of fuel, and same ignition timing (not talking modern electronic fuel injection) as when the cylinder temp was normal. This is absolutely catastrophic.

In a matter of seconds (especially in an engine that is well under load and to top it off, high RPMs) you have the cylinder temp shooting out of control. You start having detonation and pre-combustion almost immediately. In the racing world, detonation makes the most expensive ash trays you've ever seen (burnt pistons). As temps go higher, and the last little bit of coolant is sitting in the lower portion of the block, the valve guides (part of the cylinder heads - which happen to be the highest point in most engines is the 1st starved coolant area) start to immediately burn any oil off of them. It's metal on metal. Combustion now leaks right through the guide, throwing fire directly on the spring that designed to keep it seated when the lobe of the camshaft hasn't commanded it open. And in a matter of seconds, the valves are stuck. Pistons could hit those valves in a non-clearanced motor. Those cylinders have lost compression. The head gasket has long been blown. The head is warped. The engine is toast.

This process will happen in a matter of minutes without proper cylinder temperature.

A couple things to be considered. Air will not cool the cylinder of an engine. I do not care if you are in the Arctic or the most miserably cold place on the planet, or at 40,000ft in an airplane. Air only cools the coolant. It needs to be there. 4000F can not be cooled without a liquid. Air cooled engines have special fins and metals that will dissipate heat allowing air to cool them. The reason being, the cylinder is located on the outer most part of the engine. A typical V-series engine, the cylinders are located inside huge cylinder walls that are surrounded by huge areas of coolant passages, then another layer of metal beyond that which is the outside of the block. Air will have zip to do with a v-style engine in cooling it (other than cooling the coolant itself)

In saying this, I doubt we have every variable working in the sim. I remember bugs of the temperature gauge still creeping up with an engine off and so forth. *pure speculation* I imagine a fighter aircraft has a small cooling system. There's just not much space to stuff everything in there. So any loss of coolant is probably pretty significant to the operation of the cooling system in a fighter.

Just my thoughts, but I think what we have now is pretty good. But it's a shame if we still have the engine off / temp rises bug still. Either way it's much better and much more realistic than what we had before.


That is why the devs left it out of the original release, the realities of temperature they felt would cause complaints...much like this thread:-P

Anders_And 12-01-2012 05:46 PM

[QUOTE=ATAG_Bliss;484935]Just wanted to add what's been said by swiss.

Coolant is there simply to maintain an operating temperature for good combustion. To put into perspective, gasoline (oil based) combustion is around 4000 degrees (2100-2200C). This is the temperature inside the cylinder every single time that particular cylinder fires with fuel. In very simple terms, coolant is circulated from the radiator and then to the engine and back again. The thermostat controls this flow of coolant. The coolant in the engine reaches temperature (say 210F) then the thermostat opens allowing for the coolant that has been sitting in the radiator (cooled by air passing through it) to then go into the engine again, while the hot stuff sits in the radiator. Depending on the application / temperature / load on the engine, this process could take place at a constant dribble (constant recirculation of coolant from the engine to the radiator) or it could happen several times a minute (t-stat opening and closing).

The second you don't have coolant to replace the hot stuff in the engine you're gonna have some major problems. If anyone remembers good old carbs, we used to have choke horns, idle bleeds, metering plates, high speed air bleeds, etc.. With the choke on (engine cold) we are restricting air into the engine. This is creating a rich situation (excess fuel). But the engine needs this fuel to run with a low temperature cylinder.

With that said, imagine you have a perfectly running engine (cylinder temperature is on the money, choke is not being used etc.) Just imagine what happens when air temperature in the cylinder is too hot. Remember, when it's cold, we need an excess amount of fuel and less air to keep the engine even running. But we know this when starting the engine. We pull the choke cable and get the ol girl fired up. But when the cylinders creep up in temp (over normal) from a coolant loss, we are still pumping the same amount of air, same amount of fuel, and same ignition timing (not talking modern electronic fuel injection) as when the cylinder temp was normal. This is absolutely catastrophic.

In a matter of seconds (especially in an engine that is well under load and to top it off, high RPMs) you have the cylinder temp shooting out of control. You start having detonation and pre-combustion almost immediately. In the racing world, detonation makes the most expensive ash trays you've ever seen (burnt pistons). As temps go higher, and the last little bit of coolant is sitting in the lower portion of the block, the valve guides (part of the cylinder heads - which happen to be the highest point in most engines is the 1st starved coolant area) start to immediately burn any oil off of them. It's metal on metal. Combustion now leaks right through the guide, throwing fire directly on the spring that designed to keep it seated when the lobe of the camshaft hasn't commanded it open. And in a matter of seconds, the valves are stuck. Pistons could hit those valves in a non-clearanced motor. Those cylinders have lost compression. The head gasket has long been blown. The head is warped. The engine is toast.

This process will happen in a matter of minutes without proper cylinder temperature.

A couple things to be considered. Air will not cool the cylinder of an engine. I do not care if you are in the Arctic or the most miserably cold place on the planet, or at 40,000ft in an airplane. Air only cools the coolant. It needs to be there. 4000F can not be cooled without a liquid. Air cooled engines have special fins and metals that will dissipate heat allowing air to cool them. The reason being, the cylinder is located on the outer most part of the engine. A typical V-series engine, the cylinders are located inside huge cylinder walls that are surrounded by huge areas of coolant passages, then another layer of metal beyond that which is the outside of the block. Air will have zip to do with a v-style engine in cooling it (other than cooling the coolant itself)

In saying this, I doubt we have every variable working in the sim. I remember bugs of the temperature gauge still creeping up with an engine off and so forth. *pure speculation* I imagine a fighter aircraft has a small cooling system. There's just not much space to stuff everything in there. So any loss of coolant is probably pretty significant to the operation of the cooling system in a fighter.

Just my thoughts, but I think what we have now is pretty good. But it's a shame if we still have the engine off / temp rises bug still. Either way it's much better and much more realistic than what we had before.[/QUOT


Thx! very informative!

Anders_And 12-01-2012 05:48 PM

Quote:

Originally Posted by SlipBall (Post 484941)
That is why the devs left it out of the original release, the realities of temperature they felt would cause complaints...much like this thread:-P

Ah so when something is wrong and it will cause complaints it is right to leave it out to avoid complaints about it...

Great way of arguing

SlipBall 12-01-2012 08:31 PM

Quote:

Originally Posted by Anders_And (Post 484948)
Ah so when something is wrong and it will cause complaints it is right to leave it out to avoid complaints about it...

Great way of arguing


In both scenarios the battle is over once you get a leak, there can be only the option to seek a safe landing. With the motor seizing, now you really need to be high up if a great distance is ahead of you. Its ok that way, but there is less chance of success to reach friendly territory now... I liked it better the other way, and the pilot should not mind me trying to get home, he ended the battle between us and left me to fate.

FFCW_Urizen 12-01-2012 08:47 PM

The thing is SlipBall, before the change you could lose all (!) of your coolant, without ever(!) running into problems. You really liked it better that way? Because that´s the way your post comes across. If i misunderstood that, sorry in advance.

S!

SlipBall 12-01-2012 08:59 PM

Quote:

Originally Posted by FFCW_Urizen (Post 484974)
The thing is SlipBall, before the change you could lose all (!) of your coolant, without ever(!) running into problems. You really liked it better that way? Because that´s the way your post comes across. If i misunderstood that, sorry in advance.

S!

Maybe that is true with one of the patches I can't remember that. With the vershion that I fly most, any coolant leak gives loss of power, and so fight is over, run for it at a crawl...only one difference between the two, and that is the engine will now seize,..loss of power is the same, oil on window is the same, speed is slightly reduced now to about 180 from 200 with the E3


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