Engine runs with mags off?

[hazzer]

Hi all, 

This has long been something that has confused me. Haven't posted it in the hug section yet as I'm not sure if the P51 has a weird set up. 

I have always noticed that the engine catches before 

Hi all, 

I haven't posted this in the bug section as I'm not sure it is yet. Hoping we can confirm if it is correct or not. 

Usually with these aircraft you would start by holding down the starter and counting the prop blades, before turning the mags on and introducing a spark into the mix. 

 

This does not work in DCS. When the starter is held the engine actually fires up. If you keep the starter held down the engine will continue to run, even if the mags are off. 

 

To me this seems very wrong, can someone wiser please confirm or deny?

[=475FG= Dawger]

29 minutes ago, hazzer said:

Hi all, 

This has long been something that has confused me. Haven't posted it in the hug section yet as I'm not sure if the P51 has a weird set up. 

I have always noticed that the engine catches before 

Hi all, 

I haven't posted this in the bug section as I'm not sure it is yet. Hoping we can confirm if it is correct or not. 

Usually with these aircraft you would start by holding down the starter and counting the prop blades, before turning the mags on and introducing a spark into the mix. 

 

This does not work in DCS. When the starter is held the engine actually fires up. If you keep the starter held down the engine will continue to run, even if the mags are off. 

 

To me this seems very wrong, can someone wiser please confirm or deny?

More of a sound issue than anything. If you have to hold the starter to keep it turning, the starter is doing the turning and should catch on fire if you do it too long.

[hazzer]

54 minutes ago, =475FG= Dawger said:

More of a sound issue than anything. If you have to hold the starter to keep it turning, the starter is doing the turning and should catch on fire if you do it too long.

Maybe I didn't explain it very well.. 

The engine runs if the starter is held in, as if the mags are turned on. Which should not happen as far as any aircraft I understand or know about. As the magneto is what provides the spark, so with them off the engine should turn over, but not catch and start. 

 

Hope that explanation sort of makes sense, in the current state I belive it is inaccurate unless someone can show me some documentation which says it is correct that there is a spark in the cylinder when the starter switch is engaged. 

[Art-J]

That's been popping up every now and then for years in this section of the forum.

DCS Mustang, just like the Spit (same engines in practical term) has a booster coil in its ignition system, which powers up plugs during cranking even when mags are off (as they might not fire when cranking speed is too low, ie. very cold engine). Unlike in the Spit though, here we've got starter and booster wired to a single switch.

Granted, there is a simplification/bug in DCS, which makes it possible to even fly the Mustang continuously with mags off, just by keeping the starter switch on all the time (which would quickly kill both starter and booster in real life I'm sure), but I don't think ED will bother fixing it, since flying that way is only something dedicated loophole-searchers and nitpickers would do just for the feck of it and the switch is spring-loaded anyway (unless you assign it to otherwise in your HOTAS), plus I recall the engine develops severely limited power in such scenario.

[hazzer]

10 hours ago, Art-J said:

That's been popping up every now and then for years in this section of the forum.

DCS Mustang, just like the Spit (same engines in practical term) has a booster coil in its ignition system, which powers up plugs during cranking even when mags are off (as they might not fire when cranking speed is too low, ie. very cold engine). Unlike in the Spit though, here we've got starter and booster wired to a single switch.

Granted, there is a simplification/bug in DCS, which makes it possible to even fly the Mustang continuously with mags off, just by keeping the starter switch on all the time (which would quickly kill both starter and booster in real life I'm sure), but I don't think ED will bother fixing it, since flying that way is only something dedicated loophole-searchers and nitpickers would do just for the feck of it and the switch is spring-loaded anyway (unless you assign it to otherwise in your HOTAS), plus I recall the engine develops severely limited power in such scenario.

Thanks, I thought I had seen it in the past reported as not a bug. Hence my question. 

The way I understand the boost coil would only work if the mags are actually turned on. Watching P51 startup videos on YouTube like kermit weeks (I know not great to use as a source but hey ho) they always count so many blades before turning the mags on, in DCS you can't do that since the engine catches well before that. 

To me it seems like some weird logic that that is how it is wired up. Not saying it's wrong if it is proven, but would appreciate some documentation actually showing that this is correct. 

[grafspee]

On 3/28/2023 at 11:27 PM, hazzer said:

Hi all, 

This has long been something that has confused me. Haven't posted it in the hug section yet as I'm not sure if the P51 has a weird set up. 

I have always noticed that the engine catches before 

Hi all, 

I haven't posted this in the bug section as I'm not sure it is yet. Hoping we can confirm if it is correct or not. 

Usually with these aircraft you would start by holding down the starter and counting the prop blades, before turning the mags on and introducing a spark into the mix. 

 

This does not work in DCS. When the starter is held the engine actually fires up. If you keep the starter held down the engine will continue to run, even if the mags are off. 

 

To me this seems very wrong, can someone wiser please confirm or deny?

War time P-51 has different setup then modern P-51s. As soon as you flip starter ignition system is energized by booster coil which takes magnetos job at low rpm.  For example Spitfire or mosquito has booster coil separate button, but in P-51 starter and ignition booster are the same switch. Modern p-51 for safety sake has booster linked to magnetos switch so it is possible to crank engine without spark but in war time P-51 it wasn't possible. And you can check if engine can freely rotate without ground crew.

Running engine on booster coil alone has draw back like significantly reduced power.

Edited June 21, 2023 by grafspee

[hazzer]

15 hours ago, grafspee said:

War time P-51 has different setup then modern P-51s. As soon as you flip starter ignition system is energized by booster coil which takes magnetos job at low rpm.  For example Spitfire or mosquito has booster coil separate button, but in P-51 starter and ignition booster are the same switch. Modern p-51 for safety sake has booster linked to magnetos switch so it is possible to crank engine without spark but in war time P-51 it wasn't possible.

Running engine on booster coil alone has draw back like significantly reduced power.

 

Excellent, thanks for the explanation. I assumed if it was modeled that way in the sim it's because of a different set up to modern day. 

Thanks!