Ammo against 109?

[Skoshi Tiger]

I'm with blackdog on this one.

Done plenty of country mile in shitty old cars with leaky radiators, stopping every thirty or fourty k's to top up the radiator water.

On the open road at speed it's mostly fine, just when you get to the city limits, slow speeds and thing's go to pot.

It all comes down to the type of location of the damage. Even unpressurised as long as the fluids circulating there is some cooling happening.

Cheers!

Originally Posted by Blackdog_kt

What you mention is an interesting point and it has been talked about various times. Naturally i got curious and some time ago i specifically tested this and i got an engine seizure.

The trick here is to know what to expect. A damaged radiator doesn't immediately shut down engine cooling, instead it leaks coolant fluid.

The amount of coolant evaporating from a damaged radiator would probably depend on the amount of damage to the radiator and how much you are pushing the engine (higher power settings result in higher coolant temperatures and pressures, which means more leaking for a given amount of damage).

Once your cooling system is emptied, it is then that engine damage occurs.

I tried this in a quick mission some time ago and it works pretty much like that. I was in a 110 and got a perforated radiator at the start of the fight. I kept flying normally for the duration of the fight, chased retreating Hurricanes all the way to Dover and then started on my way back to home base.

I had almost made it across the Channel, when the engine started overheating rapidly and seized.

If my home base was near Calais or any other airfield at the narrow point of the Channel, i would have probably made it just fine. However, i specifically decided to test the radiator DM once i got that kind of damage so i decided to fly the long way back to my designated field just to see what would happen.

I don't know how realistic it is or how complex is the modeling behind it, but overall it seems fine to me after doing the test and i like how the DM is not restricted to instantaneous effects. Radiators seem to be one of those progressive aspects of the DM that you can cautiously ignore for some time depending on the situation, but one which can have very important consequences if you don't plan for it.

In my example case, the prudent thing to do if i wasn't testing specifically with the aim of causing an engine failure, would have been to divert to an alternate field. If i had decided to set it down near Calais, i would have enough coolant for the trip plus a couple of go-arounds/missed approaches.

You could easily test it out yourself, without even having to engage enemy AI and hope they hit your radiators. Just push the engine over the limits for a while to cause some intentional radiator damage. The easiest way to do it would be to go maximum power with the radiators closed at slow speed (that is, a full power climb at a steep angle). The coolant temperature will go way up and the resulting increase in pressure will break your coolant system.

From that point on you can just fly around and see how long it takes for the engine to seize, probably using a bit of time compression too. Cheers

[Blackdog_kt]

Originally Posted by trademe900

Actually, it is unrealistic. If you've done much tinkering with engines then you'll know this is a glaring fault.

Water at high temperatures in a pressurized cooling system is going to spurt out with fury if there is damage induced by a bullet. If there is the a leak the system loses it's ability to pressurize the coolant and then no amount of water will help as without pressurization it will start to boil within seconds. Immediate overheating will ensue.

That was actually the point where i had doubts. I think the mechanic i described is sound, but what i have no first-hand knowledge of is how fast the cooling system empties.

If its pressurized like you say (and now that you mention it, it sounds reasonable for it to be pressurized) then of course it will empty fast. I know for a fact that the Spit had such a system, i have flown the A2A accusim Spit for FSX on a friend's PC and the over-pressure valve in front of the cockpit is clearly mentioned in its manuals.

On the other hand, there are a handful of aircraft in the sim that have non-pressurized systems. The Stuka is definitely one of them. The 110 could be another and, by extension, maybe the 109 too.

About the Stuka, it's stated in the manual of the sim: because the system is unpressurized, the allowable max temp decreases the higher you go. I guess this is because liquids evaporate easier when the ambient pressure is lower. So, to keep the coolant in liquid form at high altitudes you need to have lower temps, maybe because the steam isn't effective at cooling.

As for the 110, it has allowed temp zones depending on altitude marked on its temp instruments, just like the Stuka, which probably indicates a similar system.

In such a case the discussion broadens a bit and we have a set of pros and cons for each system: pressurized ones are more efficient in cooling but empty faster, while non-pressurized ones take longer to empty when damaged but limit your max temps at higher altitudes.

I'm not stating definite facts here, just making a series of what to me seem reasonable assumptions, so if anyone with more knowledge can chip in that would be great. Maybe we should form the whole thing up into a CEM-related suggestion/improvement request?

[Flanker35M]

S!

Every book I have read from WW2 have one thing in common regardless country they flew for: puncture/leak/damage in cooling system and they started looking for shortest route to a safe landing. Those engines did not like overheating and seizure of them could cause fire or worse. Current CEM in CoD needs some overhaul as does many other things. But liquid cooling system is a fragile thing, especially in high performance aircraft engines.