Bristol Beaufighter with Griffon engines

[Nick Sumner]

This is a well known photograph of the Bristol Beaufighter with Griffon engines but the two nacelles look quite different. The port nacelle, nearest the camera, has no exhaust stubs whereas the starboard one does. There also seems to be an air intake behind the propeller on top of the starboard nacelle but none on the port. Anyone know what's going on here?

 

[Wurger]

Here another shot of the kite....

The pic source: Rolls Royce Hucknall

 

[tomo pauk]

The outboard exhaust manifold was probably of the flame-hiding (or collector) type, since the Beaufighter in question seems to be a night fighter? Should be harder to spot it in the night from sides? OTOH, the ejector-type exhausts offer much better exhaust thrust.

 

[Milosh]

Beaufighter MkIIF

Wurger, link says Merlin powered.

 

[Greyman]

T3177 was a Mk.IIf -- before being modified for trials with Griffon IIb engines.

 

[Wurger]

Beaufighter MkIIF

Wurger, link says Merlin powered.

Yep... if there is a WW2 Rolls-Royce in-line engine it must be the Merlin. In the same way, if there is the swastik on a plane it has to be German's. Right?
Of course the post there is incorrect. But the site is the source of the pic and I have been obliged to mention about that here.

T3177 was a Mk.IIf -- before being modified for trials with Griffon IIb engines.

I agree.

IMHO the answer to the request may be found in the Valiant Wings Publishing Airframe Album 14 - The Bristol Beaufighter book.

The pic source: Valiant Wings Publishing Airframe Album 14: The Bristol Beaufighter | Large Scale Planes

 

[Nick Sumner]

The outboard exhaust manifold was probably of the flame-hiding (or collector) type, since the Beaufighter in question seems to be a night fighter? Should be harder to spot it in the night from sides? OTOH, the ejector-type exhausts offer much better exhaust thrust.

But the inner exhaust would impair pilot vision.

 

[fastmongrel]

But the inner exhaust would impair pilot vision.

My thoughts exactly

 

[Nick Sumner]

Looks like an interesting book, does anyone have a copy and would they be willing to share the info? Because of where I live, postage makes it a bit expensive to buy from the publisher; according to Bookfinder, other outlets want BIG money for it and due to the apocalypse the interlibrary loan system is shut down.

 

[fastmongrel]

Looks like an interesting book, does anyone have a copy and would they be willing to share the info? Because of where I live, postage makes it a bit expensive to buy from the publisher; according to Bookfinder, other outlets want BIG money for it and due to the apocalypse the interlibrary loan system is shut down.

I have just ordered it, I am planning to build a Coastal command Beaufighter kit so I will find it very useful.

 

[WJPearce]

Paraphrased from "Hucknall — the Rolls-Royce Flight Test Establishment" by David Birch page 132:

The right engine had typical ejector exhaust stacks. The left engine had six-into-one exhaust manifolds hidden beneath the cowling and routed to exit above the wing. The manifolds were cooled by air that had passed through the radiator. When the radiator side exits were closed, the only air exit would be that around the manifolds above the wing. The configuration was intended to improved streamlining and provide flame dampening. However, the exhaust manifolds were not structurally reliable and frequent repairs were needed.

 

[Nick Sumner]

Paraphrased from "Hucknall — the Rolls-Royce Flight Test Establishment" by David Birch page 132:

The right engine had typical ejector exhaust stacks. The left engine had six-into-one exhaust manifolds hidden beneath the cowling and routed to exit above the wing. The manifolds were cooled by air that had passed through the radiator. When the radiator side exits were closed, the only air exit would be that around the manifolds above the wing. The configuration was intended to improved streamlining and provide flame dampening. However, the exhaust manifolds were not structurally reliable and frequent repairs were needed.

Thank you!

 

[spicmart]

Can you give performance stats for this Beau?

 

[WJPearce]

Can you give performance stats for this Beau?

I don't have any and there were none in the Hucknall book. Maybe fastmongrel will find something in the book he ordered.

 

[fastmongrel]

I don't have any and there were none in the Hucknall book. Maybe fastmongrel will find something in the book he ordered.

I have been so busy recently I haven't had a chance to do more than flick through the book.

 

[spicmart]

Could this Griffon-powered variant catch up to the Mosquito performance-wise?

 

[fannum]

No. It was at least 50-70 mph slower, although it had longer range.

 

[Admiral Beez]

Could this Griffon-powered variant catch up to the Mosquito performance-wise?

Did the Mosquito ever get tested with Griffons? Interestingly, even the Sea Hornet stuck with Merlins.

 

[Clayton Magnet]

Did the Mosquito ever get tested with Griffons? Interestingly, even the Sea Hornet stuck with Merlins.

I think the Hornet went with Merlin engines to keep the frontal area as small as possible. Streamlining and frontal area were prime design concerns for the Hornet, but not so much the Beaufighter.

 

[Shortround6]

For the Hornet you had the streamline thing going.
The Merlins for the Hornet were smaller profile that standard Merlins. Or had things like sloped valve covers to help with the streamline profile.

Griffons are not exactly interchangeable with Merlins. The bigger the plane the more room you have to move things around.
A two stage Griffon was about 400lbs heavier than the Merlin 130s used in the Sea Hornet. And that is for the bare/dry engine. You are going to need more coolant, larger radiators, more oil, etc. Not to mention, bigger props.

The Hornet was a not a Mosquito with a skinny fuselage. The Hornet used a wing that 9ft shorter and just under 90 sq ft smaller in area. (79.5%)

The Beaufighter was more of a moving van to begin with. Wing was 10.8% bigger than a Mosquito wing and with the radial engine cowls and air intakes there was a lot that needed work on the Beaufighter to get it anywhere near being a speed demon.