Author Topic: About MW50s.. (Read 530 times)

Kweassa · « **on:** February 24, 2004, 12:42:35 AM »

Guys, I forgot why one shouldn't engage the MW50 device at high boost/RPMs.

I remember something having to do with pressurization process, and they would typically "arm" the system before take off.. but forgot all the details.

Can anyone enlighten me?

Wmaker · « **Reply #1 on:** February 24, 2004, 07:17:27 AM »

Reason for not engaging it was that the engine couldn't handle the high manifold pressure (1.7-1.92 ATA) without mater-methanol being there to rise the octane level of the fuel mixture and to work as an antidetonant.

So the MW-50 was to start flowing while you were still within military power limits. After it started flowing you could push the MAP for higher figures.

HoHun · « **Reply #2 on:** February 24, 2004, 11:37:33 AM »

Hi Kweassa,

>Guys, I forgot why one shouldn't engage the MW50 device at high boost/RPMs.

Actually, it worked exactly opposite to that :-)

MW50 injection was armed by flipping a switch on the dashboard.

Injection was only activated, though, when the throttle was advanced to the stop.

That means MW50 was only injected once war emergency power was reached, at full boost, at full rpm. The resulting power setting was called "special" war emergency power to discern it from emergency power without additional injection.

MW50 was automatically deactivated when the MW50 stopped flowing (because the supply was exhausted).

MW50 could be used for 10 min at a time, and the German fighters typically carried enough for 40 min of operation at special war emergency power.

The downside was that spark plug life was reduced to 15 to 30 hours.

(Main source: von Gersdorff et al.)

Regards,

Henning (HoHun)

Kweassa · « **Reply #3 on:** February 24, 2004, 12:02:46 PM »

Oops, a bit of misunderstanding there, Hohun.

I'm aware how the MW50 works, but I was wondering why the "arming" process was limited to lower boost/RPMs - requiring the typical procedure of arming the MW50 system before take-off.

What would happen, if a pilot, forgot to "arm" the system before take-off, and "armed" the MW50 when emergency power was already engaged?

HoHun · « **Reply #4 on:** February 24, 2004, 01:10:50 PM »

Hi Kweassa,

>I'm aware how the MW50 works, but I was wondering why the "arming" process was limited to lower boost/RPMs

It wasn't :-)

>requiring the typical procedure of arming the MW50 system before take-off.

The switch was on the dashboard. It could be armed in flight.

>What would happen, if a pilot, forgot to "arm" the system before take-off, and "armed" the MW50 when emergency power was already engaged?

Well, forgetting of course is impossible, but MW50 is injected only if two switches are activated. One switch is on the dashboard, the other switch is on the throttle and activated when it hits the stop. The sequence doesn't matter.

As Pyro pointed out on the AH2 board, WW2 designers were constantly trying to make things simple and safe for the pilots :-)

Regards,

Henning (HoHun)

Kweassa · « **Reply #5 on:** February 25, 2004, 03:31:24 AM »

Ouch, that's got me really confused.

In Forgotten Battles, when you "arm" the MW50 system at high RPMs, it damages the engines, and the engine loses power and than seizes up after a short while.

You mean that this, is wrongly portrayed in that game?

Glasses · « **Reply #6 on:** February 25, 2004, 10:30:21 AM »

I always engage the MW50 system below 95% power and it activates itself when you go above 99%. I don't think it's portrayed erroneuosly. In fact I think you can engage it below 100% power but I let it slide a bit below 95% before I activate MW50 to be safe.

Batz · « **Reply #7 on:** February 25, 2004, 10:38:13 AM »

Glasses is right in FB you don't to be at idle

I switch it on at 90 - 95% throttle and leave unless I go above critical alt then I just shut it off.