Did a little research about MW50 in the FW190A-Series

[funkedup]

"96" or "c3" would indicate mw50 installation.

Not

[-ik-]

a little too concise, funkedup?

I'm a little curious as to your objection, for everything I've read about mw50 says that its installation is marked by the different fuel triangle;  aircraft without mw50 have the normal "87" fuel triangle.

[wells]

ik,

The 190s could use a petrol injection system, injecting c3 fuel in combination with higher boost.  This does not necessarily mean that MW50 was used.  Likewise, you can inject MW50 with any fuel, it doesn't have to be c3.  It will allow higher boost pressures, regardless.  The 109s used MW50 with B4 fuel (605DB) and with C3 fuel (605DC).

[-ik-]

Good point, a logical slip-up on my part I guess.  Whenever I've read about MW50 conversion, mention of switching to 96 octane fuel is always given; you're right that it would be wrong to conclude from the fuel triangle that mw50 was present.

[Naudet]

The fuel triangles show exactly what a LW plane uses.

If it has MW50 installed, the fuel triangle on port side aft fuel intake (for the 115liter tank) will read "MW50", colours vary from yellow to red, and triangle might even stand on the top.

The triangles on the other fuel intakes will either be "b4" or "c3" and this just indicates which type of fuel is to be used.

But you can't say from "b4" or "c3" fuel triangle if there is a MW50 installation.

[Hristo]

I find it curious that someone rejected a significant increase in horsepower (as with MW50) because of damage to sparkplugs (which are cheap and easily changed).

If my life depended on MW50, I'd buy sparkplugs myself

[Naudet]

Hristo, i think the increased overall maintainance efforts neccessary for an MW50 equited BMW801 were considered to high to use MW50 as standard boost in FW190As.

The effect on the sparkplugs is just the most significiant. If i remember right, sparkplug life was reduced to 25% of the standard time. Just imagine how "dirty and hot" the ignition process must have been to have such an effect on the sparkplugs.
And i am sure valves and cylinders didnt take it the "easy way" when MW50 was injected.

I tend to believe that both the DB605 and JUMO213 could withstand the brutal treatment of MW50 injection better than the BMW801. Maybe it has something to do with liquid- and air-cooled.

[HoHun]

Hi Naudet,

>Just imagine how "dirty and hot" the ignition process must have been to have such an effect on the sparkplugs.

"Dirty" is not quite the right word.

MW50 actually helped to control the ignition process and as an anti-detonant enabled the engine to run closer to the theoretic optimum of the fuel-to-air ratio. (That means it runs weak, not rich. Rich mixtures lead to incomplete combustion, so they could be considered "dirty".)

Specific fuel consumption (fuel spent per HP per hour) actually could be better on MW50 than without. As this happened at very high power settings, the engine ate up a lot of fuel quickly, but it did so economically :-)

The heat buildup is not due to MW50, but due to the high power generated in the engine. If it were possible to run the engine at the same power without MW50, it would be even hotter. (This is interesting for the MW50 vs. C3 injection comparison.)

Regards,

Henning (HoHun)

[Naudet]

I knew dirty was not the best word.

If without MW50 it even gets hotter, that might be the reason why C3 injection doesn't boost HP as much as MW50 does.

But anyway, there must have been some good engineering reason why they didnt fit MW50 into any A-Series FW190 beside the A4 Jabo.

Increased stress due to higher pressure? Or Engine getting worne out due to a power output it was not intended for at that time?