Number 1 Spitfire Inverted Flat Spin Recovery

[morfiend]

^^^^

  what???



  The engine doesn't lean out,it's fuel starved there is a difference. The float bowls don't control fuel mixture so I'm not understanding where you get the leans out part.


  Under neg G the floats.....float.... and are at the top of the bowl{s} this tells the system to stop pumping fuel so that the carb doesn't flood itself. Then when all the fuel in the carb is used up the engine stops because it has no fuel.


  5 highest 0lowest notwithstanding,3 air 3 fuel,good luck getting that to run. the average fuel air mixture is around 12 to 1,go down to 10 to 1 and that's lean,got up to 14 and that's fat.


   Now go ahead and share more of your wisdom with me.





   

[nrshida]

I've been reading up on this problem and it was actually a little more involved. The carburetter was employed in the Spitfire in place of fuel injection because they believed it increased the effectiveness of the supercharger and hence gave more power (the Germans were forced to employ fuel injection because they went and built their engine upside down in the first place ).

The early versions used an SU carburetter. When bunting, the fuel was forced to the top of the float chambers causing the initial fuel starvation (spluttering and loss of power). If the negative G manoeuvre was sustained then the fuel would accumulate in the top of the float chamber and push the float downwards opening the SU's needle valve to maximum, flooding the engine and shutting it down completely.

Tilly's orifice was fitted to the fuel lines which restricted the flow and allowed just enough fuel for maximum power (clever eh?) it even came in two settings, for boosted and normal engines. The needles of the carburetters were also modified and the fuel feed moved from the bottom to the side of the float chamber.

These solutions allowed the Spitty pilots to follow the dastardly Hun through his cowardly bunting escapes and fill the blighter full of 303, preferably aiming for his knockwurst ^[1]. These problems were completely resolved with the introduction of the Bendix pressurised carburettors in '42.



^[1] "Bag the Hun: Estimation of Range & Angle Off". Air Ministry - 1943 [http://bbs.hitechcreations.com/smf/index.php/topic,297962.0.html]

[LCADolby]

, preferably aiming for his knockwurst

Not the one containing the fallen madonna with the big... http://www.youtube.com/watch?v=-OM-Hj3JEmY&feature=player_detailpage#t=367s

[nrshida]

Not the one containing the fallen madonna with the big...

 

[PR3D4TOR]

(the Germans were forced to employ fuel injection because they went and built their engine upside down in the first place (Image removed from quote.)).

The DB 601 was a fuel injected improvement over the carburetor fed DB 600. Both were of inverted-V design and I really don't understand why you would think that the orientation of the cylinders has any bearing on what fuel system they can use. Most if not all American radial engines used during the war used carburetors. The reason why the DB 600 series used an inverted-V design was because it is aerodynamically desirable. The reason why the DB 601 and its developments used direct fuel injection was because that's what the RLM decided they wanted.

[nrshida]

I really don't understand why you would think that the orientation of the cylinders has any bearing on what fuel system they can use.

 

[PR3D4TOR]

Oh you! 

[nrshida]

Hey! Someone corrected the Wikipedia page about Tilly's Orifice since yesterday. Yesterday it said the orifice was fitted to the float chamber and now it says (correctly) it was fitted to the fuel lines and mentions the flooding problem I researched. Was it one of you lot? Jolly good show if it was 

http://en.wikipedia.org/wiki/Supermarine_Spitfire#Carburettor_versus_fuel_injection

Sorry PR3D4TOR but one of my hobbies is making fun of German engineering. I actually do know rather a lot about internal combustion engines. All light hearted stuff though. Achtung Schpitfire 

[PR3D4TOR]

No harm done, except to my carpal tunnels

[LCADolby]

Sorry PR3D4TOR but one of my hobbies is making fun of German engineering. I actually do know rather a lot about internal combustion engines. All light hearted stuff though. Achtung Schpitfire 

But the Germans are so ingenius http://www.youtube.com/watch?v=8cqrQkF2ISE&feature=related 

[nrshida]

  check out his pyjamas! 

[Devonai]

I have been flying the Mk 1 exclusively this tour, and so far this has only happened to me once.  I went up and over hoping for an easy kill on a P-39D and watched in horror as my airspeed dropped to zero.  I tried all my spin recover tricks but was forced to bail at 1500 feet.  Somebody got a free kill, but I blame myself.  Now I'm far more cautious about my vertical maneuvering.

[RTHolmes]

Ive had 2 sorties in the MkI this tour, got a kill both times, and both times my sortie was ended by auto puffy ack removing a wing first burst. grrrr.

[olds442]

^^^^

  what???



  The engine doesn't lean out,it's fuel starved there is a difference. The float bowls don't control fuel mixture so I'm not understanding where you get the leans out part.


  Under neg G the floats.....float.... and are at the top of the bowl{s} this tells the system to stop pumping fuel so that the carb doesn't flood itself. Then when all the fuel in the carb is used up the engine stops because it has no fuel.


  5 highest 0lowest notwithstanding,3 air 3 fuel,good luck getting that to run. the average fuel air mixture is around 12 to 1,go down to 10 to 1 and that's lean,got up to 14 and that's fat.


   Now go ahead and share more of your wisdom with me.





   

i was playing it simple so people did not have to google stuff just to stay with us...

and when you go into lets say neg .1 gs the floats go up not all the way but some thus the engine is now leans and would stay lean if u keep it at .1 G's constantly till the engine overheats due to it being to lean
now if u go to lets say neg .6 gs the engine is starved and dies. still if the engine somehow could run it would be lean.