Spitfire Unplayable?

[utu]

Originally Posted by Dutch_851

Fuel Mixture? You should lean it out as you gain altitude.

According with several sources, the Spit (and the Hurry), has 2 positions on fuel mixture, you can use the lean position only for cruise. Climbing it has to be rich at about +6 at 2600 rpm. But I tried, moving the (inverted in the game) lever to lean produces a major engine stutter, and this is normal I think. But why the engine starts to stutter above 5000 ft????
On the other side the engine's cut on negative g is not a problem and doesn't cause problems.

Now I can manage the full CEM on the Spit and the Hurry because in combat the altitudes vary continually and mostly you finish your fighting at sea level. But if you try to return to base at high altitudes, the engine fails...

[GunnyMac]

What doe's the boost cut off do?

[ATAG_Dutch]

Originally Posted by utu

According with several sources, the Spit (and the Hurry), has 2 positions on fuel mixture, you can use the lean position only for cruise. Climbing it has to be rich at about +6 at 2600 rpm. But I tried, moving the (inverted in the game) lever to lean produces a major engine stutter, and this is normal I think. But why the engine starts to stutter above 5000 ft????
On the other side the engine's cut on negative g is not a problem and doesn't cause problems.

Now I can manage the full CEM on the Spit and the Hurry because in combat the altitudes vary continually and mostly you finish your fighting at sea level. But if you try to return to base at high altitudes, the engine fails...

Two position mixture doesn't sound right. 2 position pitch, maybe.
+6 Boost? I'd say that's too high. Try climbing at 2650 revs and +4 boost. Trim to maintain optimum climbing speed. I'm at work now so trying to do this from memory but will see what I did to get up to 20000ft. This is in the Spit, not sure about the Hurri but will try it out.

[utu]

Originally Posted by Dutch_851

Two position mixture doesn't sound right. 2 position pitch, maybe.
+6 Boost? I'd say that's too high. Try climbing at 2650 revs and +4 boost. Trim to maintain optimum climbing speed. I'm at work now so trying to do this from memory but will see what I did to get up to 20000ft. This is in the Spit, not sure about the Hurri but will try it out.

No, it has only 2 position mixture: rich and lean. Lean is for cruise, because the Spit has huge amount of fuel consumption and this is a good compromise between horizontal speed, temperatures and fuel consump. The mixture is not critical like a Cessna or other small planes, where you have to listen to the engine and then pulling or pushing the mixt lever to find the right mixture. An engine of 27 liters works different. Tried at at +4 and +2 boost, even at high, med and low rpm: climbing full CEM over 5000ft means engine's fail with Spit mkIIa (rotol prop).

[41Sqn_Banks]

I tried Spitfire I (not IA) and Hurricane I (Rotol) and managed to get both to 20,000ft. I wasn't possible to get higher.

Climb limit (30min) for Merlin II and III: +6.25 Boost and 2600 RPM
Climb limit (30min) for Merlin XII: +9 Boost and 2850 RPM (however as the boost gauge is broken at the moment it's not possible to check this)

[ATAG_Dutch]

Originally Posted by utu

No, it has only 2 position mixture: rich and lean. Lean is for cruise, because the Spit has huge amount of fuel consumption and this is a good compromise between horizontal speed, temperatures and fuel consump. The mixture is not critical like a Cessna or other small planes, where you have to listen to the engine and then pulling or pushing the mixt lever to find the right mixture. An engine of 27 liters works different. Tried at at +4 and +2 boost, even at high, med and low rpm: climbing full CEM over 5000ft means engine's fail with Spit mkIIa (rotol prop).

OK, now I have a project for tonight!

Thanks. I'll let you know later!

[ATAG_Dutch]

Originally Posted by utu

No, it has only 2 position mixture: rich and lean. Lean is for cruise, because the Spit has huge amount of fuel consumption and this is a good compromise between horizontal speed, temperatures and fuel consump. The mixture is not critical like a Cessna or other small planes, where you have to listen to the engine and then pulling or pushing the mixt lever to find the right mixture. An engine of 27 liters works different. Tried at at +4 and +2 boost, even at high, med and low rpm: climbing full CEM over 5000ft means engine's fail with Spit mkIIa (rotol prop).

Well, I've just tried it with both Mk1a and MkIIa Spits and got to 10000ft and back down again without mishap.

Once started on the ground in rich mixture, radiator fully open, allow engine to warm up to 80 degrees or so with brakes on and 0 boost.

Immediately taxi to runway and take-off at +5 boost.

As soon as you take-off, lower boost to +4 and pitch to 2650, and set engine to lean mixture.

After building up some speed, trim for climb at 160 - 180mph. Obviously IAS decreases as you climb.

Then it seems to be a balancing act between prop pitch and boost.
Coarsening the prop pitch keeps oil temp under control, lower revs=cooler oil temp, higher revs=higher oil temp. Keep to about 70 degrees.
Engine boost keeps water temp under control, keep to about 90 degrees.
I didn't go into the red boost zone at all much on the climb, so no more than +4 and sometimes as low as 0 boost.
All this was with coolant rad fully open.

After reaching 10000, I chopped the throttle and changed to rich mixture to keep the motor running, closed the coolant rad and pretty much split-'S'-ed to the deck.
For a trickle of power for landing I had to go back to lean mixture and back again to rich on chopping the throttle once on the ground again for the taxi.

Hope this helps!

[bongodriver]

bear in mind you must reduce power before reducing RPM, even modern aircraft with small engines and props don't like being overboosted.

and also increase RPM before incresing power.

[fruitbat]

now try and get to 30,000ft.

bear in mind that a lot of the fighting took place between 20,000 and 30,000ft.

[ATAG_Dutch]

Originally Posted by fruitbat

now try and get to 30,000ft.

bear in mind that a lot of the fighting took place between 20,000 and 30,000ft.

Okey Dokey. BRB.