Mosquito exhaust - 5 pipes or 6 ?

[Treez]

I am seeing photos of Mossies with 6 exhaust pipes and others with only 5. (ten total per Merlin)
The new one from NZ now flying has 5. Can anyone expand on that please ? TIA

 

[wuzak]

Mosquitoes with single stage engines, such as the B.IV, B.XX, FB.VI, FB.26 and FB.40 had 5 exhaust outlets with the rear pair of cylinders exhausting through a shared ejector exhaust.

Mosquitoes with 2 stage engines, such as the B.IX, PR.IX, B.XVI, PR.XVI and B.35 have individual ejector exhausts (6 per side of engine).

The reason is that the single stage engine's rear exhaust would interfere with the leading edge radiator, if not physically the exhaust would affect the radiator.

The 2 stage engines are several inches longer, so that problem doesn't exist.

There was at least one conversion, of a Canadian B.XX or B.25, from single stage to two stage Merlin that retained the original 5 outlet exhaust.

 

[wuzak]

Early Mossies had a couple of different exhaust styles, one of which was described as the saxophone exhaust.

Not sure if this is that type.

 

[Treez]

Thanks Wuzak, very informative.! I lived in Smithton many moons ago, great state.

 

[Crimea_River]

Here ya go:

 

[nuuumannn]

Nice pic Wuzak, that's the prototype, W4050, which originally had shrouded exhausts encased within the cowl with a single exit ahead of and somewhat below the leading edge of the wing. You can just see it in this rather blurry pic of the prototype at the top of the page here.

Vintage Aeroplane Writer: W4050 clocks 70

And here.

Home

 

[wuzak]

Nice pic Wuzak, that's the prototype, W4050, which originally had shrouded exhausts encased within the cowl with a single exit ahead of and somewhat below the leading edge of the wing. You can just see it in this rather blurry pic of the prototype at the top of the page here.

Vintage Aeroplane Writer: W4050 clocks 70

And here.

Home

I believe they had issues with that exhaust. The heat damaging the panels, or something to that effect.

 

[wuzak]

The ejector "multi-stub" exhausts gave a useful boost in performance, testing showing a 15mph gain at full throttle height in MS gear and 13mph in FS gear.

http://www.wwiiaircraftperformance.org/mosquito/dk290-b.pdf
Mosquito Performance Trials

 

[wuzak]

I lived in Smithton many moons ago, great state.

It is a nice place.

Unfortunately there is a bit of economic doom and gloom about.

 

[mhuxt]

These are the saxophone exhausts, mentioned above. The system with the single outlet pipe was only used on the very earliest Mossies - I think the original PR aircraft and some of the first bombers went into action with them, however the single pipes were soon replaced by either saxophones or stubs, depending on the time of day of use.

Think there's a quote in Sharp Bowyer - "Next time it would be easier to design the exhaust system first, then build the aircraft around it." (Or something similar.)


PS - Great pic Wuzak. How is it that despite being a Mosquito tragic for a good decade or more, I keep coming across new photos?

 

[wuzak]

PS - Great pic Wuzak. How is it that despite being a Mosquito tragic for a good decade or more, I keep coming across new photos?

Nice pic Wuzak, that's the prototype, W4050, which originally had shrouded exhausts encased within the cowl with a single exit ahead of and somewhat below the leading edge of the wing.[/url]

Thanks guys.

Good old Google search! Searched for Mosquito exhausts, and pretty much got the multi-stub exhausts. Then I added W4050 and found that pic.

 

[tomo pauk]

Great stuff there

 

[Treez]

It is a nice place.

Unfortunately there is a bit of economic doom and gloom about.

Taz is very similar to Nova Scotia, fishing,farming, lumber . . . I felt right at home there.
We were fishing abalone, good times. ( '72 - '75 )