Spitfire exhaust stacks

[helmitsmit]

Why did they change from a 6 exhaust to a 12 exhaust package? Didn't the 6 exhaust provide thrust that is why they put it on the Mk1

 

[Clave]

More power I'd guess - anything that obstructs the exhaust gases will sap the power.

There are (obviously) 12 exhaust ports on the engine, so having 6 exhausts means joined pipes, and a less 'clean' gas flow...

*this is just a theory*

 

[helmitsmit]

Yeah but then why didn't they have the 12 exhaust on all spitfire marks?

 

[Wurger]

Looking at the early versions of Spits I always get an impression that they are so light,simply lovely,on the contrary to the later ones.People in the past made many things in good taste. Maybe six pipes look better than twelve.

 

[helmitsmit]

Yeah. What do you think of the only flying Mk 2a with 12 exhaust instead of 6?

 

[Wurger]

I have done an experiment with a pic of Mk.IIa fitted with an exhaust of Mk.IXc.Look at the photos.The first one is authentic.The second pic looks a bit strage for me, doesn't it.Perhaps I'm not an artist but there is something a little wrong.As far as the flying only Mk.IIa with twelve exhaust is concerned,I think that there is no matter for many people if the spit has 6 or 12 pipes.Personally,it is ridiculous that there is no possibility today to restore an aircraft precisely.But I've seen so many strange an funny things about planes that I'm not surprised.Have You ever seen the last movie about Pearl Harbour ?.One of the main characters was fighting as a member The American Eagle unit during BOB.Spitfires, in the film, were coded with RF letters.As I know the code belonged to The Polish 303 squadron equipped with Hurricanes in that time.Or Spit Mk.IX with a earth brown-dark green camo pretending a polish MkVb one.Strange,isn't it.

Spitfire Mk.IIa
source unknown.

 

[helmitsmit]

It does and I don't think it is you (if you no what I mean) It just doesn't look right.

I've seem Pearl Habour and I laughed.

 

[Wurger]

I laughed too.My friends had to invite me for beer to make me quiet.You must trust me that the hangover was enormous.

all the best

 

[helmitsmit]

Yeah can imagine

 

[pbfoot]

I believe to obtain maximum horse power all the exhaust headers should be the same length this would also prevent burning the valves on certain cylnders because of unequal backpressure

 

[Wurger]

It's a good point Pbfood.

 

[Wurger]

... the only flying Mk 2a with 12 exhaust instead of 6?

Do You have any pics of the spitfire?

 

[helmitsmit]

Here are some picture of the Mk 2as I was talking about.

 

[Wurger]

Thanks mate.Looking at these I'm not convince of its being MkII.It looks as two in one.Maybe, sombody of mates knows more on the Spit.I have to check it.

to next contact.

 

[helmitsmit]

Yeah I have a book at home which has that mark two in it close up and flying. I look like a merlin 61 series attached to a mk 2. Because if the mk 2 intercoller duct under the nose. Hay that might be dangerous as later mks had bigger intakes!

 

[Jabberwocky]

The Spitfire originally didnt have any exhaust stacks. Three were added to the Merlin K on the Spitfire prototype. The bonus thrust from the exhaust was calculated to be worth an extra 70hp.

Mks I-V all had the 'fish tail' or triple exhaust stacks. All the later marks, including the Griffon engined marks, had the 'multi-ejector' type, 6 a side exhausts, which had marginally less drag and gave slightly more thrust.

I have some pictures of 1944 Spitfire LF Mk Vs with clipped wings and late model stlyle multi-ejector exhausts. Going of RAE performance measurements, they would of added about 6-8mph in speed to the airframe in place of the older style 'fish tail' triple ejector stacks. Failry useful for a fighter that topped out at 355 mph.

 

[the lancaster kicks ass]

Gentlemen i can assure you that's a Mk.IIa, she belongs to the Battle of Britain Memorial flight and is the oldest spitfire still flying today, she still carries repair marks from where she was hit during the battle of britain!

 

[Wurger]

Hi Lanc !!!
It is a nice info on the Spit.However, Helmitsmit and me agreed that she looks a bit strange with 12 pipes exchaust.Do You know if she was fitted with the later RR engine?

 

[the lancaster kicks ass]

if my memory serves me correctly she was grounded for a large part of the 1996-7 display season due to a lack of engines, so it is very possible that it was then that she was fitted with a later mark of engine.............

 

[Wurger]

That's I think in the way.