wip Over-cooling

[NineLine]

I did a test, and flew at 1900 RPM and 0 boost. I was able to fly for and hour and 30 minutes until the engine started to run rough, I then gave it some RPMs and it cleaned right up. SO yeah, 30 mins is just good practice so you don't get caught all fouled up at the wrong time. 

[Gunfreak]

This is very good news.

I did a low level dogfight today (air start) fight happened at 1000 feet.

Ran on full WEP for most of the 8 minutes the fight lasted (some throttling down at top of verticals) but mostly full 3000RPM and 18+ boost.

Engine survived just fine. Throttled down to. 2650 and 7+ and engine seemed fine. This seems realistic and nice.

 

So the Spit is finally shaping up. If the cockpit could an visual update that would be fantastic. 

 

I also hope it one day will get 150 fuel and option for .50 cals.

[Wiggy]

An option for .50 cals means it wouldn’t be a MkIXc. 
 

Anyway over-cooling issue seems to be fixed, thanks chaps!

[Rutch]

Sorry to try and reopen this, but as people have observed, the overcooling appears to have been fixed. That said, the coolant temperature is still dropping below 40 degrees when flying at say 20,000 or 30,000 feet… or at high speed in a shallow dive from height  

Should the radiator have an auto feature to prevent it dropping below 60 degrees?

All the best. 

[grafspee]

18 hours ago, Rutch said:

Sorry to try and reopen this, but as people have observed, the overcooling appears to have been fixed. That said, the coolant temperature is still dropping below 40 degrees when flying at say 20,000 or 30,000 feet… or at high speed in a shallow dive from height  

Should the radiator have an auto feature to prevent it dropping below 60 degrees?

All the best. 

In spitfire coolant circuit should consist thermostatic valve which should prevent coolant temp going down too much. Iirc temp set was 80C.

In p51 temp is regulated via actuating shutter doors in spitfire those shutter doors have 2 fixed positions with no intermediate positions.

Edited January 29, 2024 by grafspee

[Rutch]

On 1/29/2024 at 11:41 AM, grafspee said:

In spitfire coolant circuit should consist thermostatic valve which should prevent coolant temp going down too much. Iirc temp set was 80C.

In p51 temp is regulated via actuating shutter doors in spitfire those shutter doors have 2 fixed positions with no intermediate positions.

Thank you. So in theory, the coolant temp should never drop below 60? Given the thermostatic valve in place?

thanks 

[grafspee]

On 1/30/2024 at 6:30 PM, Rutch said:

Thank you. So in theory, the coolant temp should never drop below 60? Given the thermostatic valve in place?

thanks 

Pretty much all thermostatic valves in coolant circuits consist small opening which is opened even when valve is completely closed, reason for this is to push a little bit of hot coolant to other side of valve so it can react quicker and with better precision, so in theory if you would cut throttle completely and put plane into long dive temp could drop below 60C but it would took a lot of time. Flying at even very low power like boost +0 at 2000rpm this setup should hold that 80C with no problem. 

Another positive factor of this thermostatic valve is that warming engine up especially in sub zero temp will happen very fast due to that coolant flow through radiator is near zero up to 80C.

P-51 had special attachment, for cold weather to prevent overcooling in flight, which restrict flow through belly air scoop.

Edited February 1, 2024 by grafspee

[Rutch]

On 1/30/2024 at 7:45 PM, grafspee said:

Pretty much all thermostatic valves in coolant circuits consist small opening which is opened even when valve is completely closed, reason for this is to push a little bit of hot coolant to other side of valve so it can react quicker and with better precision, so in theory if you would cut throttle completely and put plane into long dive temp could drop below 60C but it would took a lot of time. Flying at even very low power like boost +0 at 2000rpm this setup should hold that 80C with no problem. 

Another positive factor of this thermostatic valve is that warming engine up especially in sub zero temp will happen very fast due to that coolant flow through radiator is near zero up to 80C.

P-51 had special attachment, for cold weather to prevent overcooling in flight, which restrict flow through belly air scoop.

Thank you very much for this excellent explanation grafspee. 
 

For this reason I wish the DCS spit would reflect this. When flying at low boost and RPM and at higher altitudes, when I check the temps I am not seeing what I would expect I.e. I am seeing coolant at 40 degrees rather than above 60.  
 

I wonder whether the technical people could further update the spit. At the moment I am warning up my engine so the coolant is > 60 degrees but as soon as I take off and throttle back to low boost it drops below 60, which doesn’t seem right. 

[Rutch]

On 12/30/2022 at 5:21 PM, NineLine said:

 

I did a test, and flew at 1900 RPM and 0 boost. I was able to fly for and hour and 30 minutes until the engine started to run rough, I then gave it some RPMs and it cleaned right up. SO yeah, 30 mins is just good practice so you don't get caught all fouled up at the wrong time

 

Hi NineLine, is there any chance this could be looked at? Thank you 

[Skewgear]

It's fine as is. The cooling system keeps a constant low level of flow going even when the thermostatic valve is "closed", else no heat would be removed from the engine at all.

[NineLine]

2 hours ago, Rutch said:

Hi NineLine, is there any chance this could be looked at? Thank you 

I would need more details on what you feel is wrong, a track showing it and evidence it does or doesn't happen in real life. Thanks. 

[Rutch]

21 hours ago, Skewgear said:

It's fine as is. The cooling system keeps a constant low level of flow going even when the thermostatic valve is "closed", else no heat would be removed from the engine at all.

I understand that it still allows some flow through, but given the minimum temperature of the radiator is 60 degrees, then when it drops to just above 40, I wonder whether a) that’s an issue and b) whether that would happen for real? 
 

if I was a pilot in ww2, flying at 20,000 feet over France and suddenly my radiator temperature dropped to c. 40 degrees, I might start to worry…

[Rutch]

@NineLine I believe @grafspee and a few others have provided Rolls Royce documentation to support the point that the spitfire (in most cases) had a thermostatic valve, which keeps the RAD temp at 80 degrees or above. 
 

I will try and do a track to show it < 60 degrees in general flight