Jump to content

Spitfire & Hurricane Merlin Exhausts


Tbolt

Recommended Posts

The 3 stack exhaust pipes used on the Merlin has the 3 sections connected. Is this just a solid connection or are do the exhaust gases mix in the 3 stacks? I'm guessing it's the later but not positive that is correct.

 

1-4-Kidney-1024x682.jpg

 

 

Edited by Tbolt
Link to comment
Share on other sites

5 minutes ago, dogsbody said:

They are 3 separate outlets, each pair fed from two cylinders.

 

Chris

I realize that each one is fed from two cylinders but your saying that the connection between them is just structural?

Edited by Tbolt
Link to comment
Share on other sites

If you search Google images "interactive Rolls-Royce Merlin 45 Manual" it should give you a picture showing the make up of a similar merlin exhaust set-up.

 

HTH

 

IanJ 

  • Like 1
Link to comment
Share on other sites

2 hours ago, Tbolt said:

I realize that each one is fed from two cylinders but your saying that the connection between them is just structural?

On your resin castings, yes. On the real thing, there was no connection between each section.

 

 

Chris

Link to comment
Share on other sites

58 minutes ago, Bonhoff said:

If you search Google images "interactive Rolls-Royce Merlin 45 Manual" it should give you a picture showing the make up of a similar merlin exhaust set-up.

 

HTH

 

IanJ 

Thanks for the tip.

Link to comment
Share on other sites

2 hours ago, Tbolt said:

I realize that each one is fed from two cylinders but your saying that the connection between them is just structural? 

My understanding, and what I think Chris was meaning, is that they are 3 separate parts, there is no physical connection between them.

The picture I found from IanJ's google search here  shows 3 types of exhaust for a merlin 45, individual stubs, very clearly separated 3 part fishtail stubs with gun heating tube arrangement, and your triple ejector nozzle type stubs. These have been laid out for the photograph as per fitted to the engine, but if you look closely the 3 pieces don't quite line up.

Each pair of cylinders shares a common stub and exhausts through that stub only

  • Like 1
Link to comment
Share on other sites

12 minutes ago, dogsbody said:

On your resin castings, yes. On the real thing, there was no connection between each section.

 

 

Chris

OK thanks, I just used that picture because it was the clearest I had. After using Bonhoff's search I came up with this picture and you can see they have tube running through them. which I guess it what's represented in the smaller scale.

 

21550.jpg

 

Edited by Tbolt
Link to comment
Share on other sites

26 minutes ago, Dave Swindell said:

My understanding, and what I think Chris was meaning, is that they are 3 separate parts, there is no physical connection between them.

The picture I found from IanJ's google search here  shows 3 types of exhaust for a merlin 45, individual stubs, very clearly separated 3 part fishtail stubs with gun heating tube arrangement, and your triple ejector nozzle type stubs. These have been laid out for the photograph as per fitted to the engine, but if you look closely the 3 pieces don't quite line up.

Each pair of cylinders shares a common stub and exhausts through that stub only

Thanks, was getting there myself. So the tube through the middle is for the gun heating? And the main thing we are seeing when they are assembled is the flange of the hole. I wonder what the type without the gun heating is like? Is there gap or a capped flange?

 

supermarine_spitfire_mk1a_p9444_04_of_37

 

Edited by Tbolt
Link to comment
Share on other sites

21 minutes ago, dogsbody said:

Is there a tube running through the pipes in Group 2?

 

Here are the various Merlin exhaust types.

 

42190981754_83d6efa412_b.jpg

 

 

Chris

That;s a good question, were the two front manifolds the same, but with the holes capped of?

 

It's frustrating that when I was last around a Hurricane I could have looked at this!

Edited by Tbolt
Link to comment
Share on other sites

 

12 minutes ago, Tbolt said:

Thanks, was getting there myself. So the tube through the middle is for the gun heating? So would it still be there on aircraft without the gun heating as not all aircraft had the pipe coming out the back of the rear exhaust? Or do we only see a capped flange?

In type 1, the long tube in the right hand section goes through a tube in each of the stubs, the tube in each stub is sealed on the exhaust side.

In type 2 the end plates are blank where the tube is in type 1, capped flange as you say.

  • Like 2
Link to comment
Share on other sites

4 minutes ago, Dave Swindell said:

 

In type 1, the long tube in the right hand section goes through a tube in each of the stubs, the tube in each stub is sealed on the exhaust side.

In type 2 the end plates are blank where the tube is in type 1, capped flange as you say.

Excellent thank you.

  • Like 1
Link to comment
Share on other sites

Hi

    So does anyone know how the air heated by the exhaust gets to the guns ? 

 

  is there a tube continuing from the manifold into the cowling ?

 

  and where does it enter ? 

 

    cheers

      jerry

  • Like 1
Link to comment
Share on other sites

3 hours ago, brewerjerry said:

Hi

    So does anyone know how the air heated by the exhaust gets to the guns ? 

 

  is there a tube continuing from the manifold into the cowling ?

 

  and where does it enter ? 

 

    cheers

      jerry

The gun heating tube turns inboard 90deg immediately aft of the exhaust stubs, passing through a notch in the top of the removable cowling side panel. It then turns aft again to the firewall, down the firewall to the spar mounts, then outboard in front of the spar. The pipe splits and vents through the spar into the two 0.303 gun bays. Note the cannon heating was provided through the ducting from the radiators previously used for all 8 0.303's on the A wing, this was insufficient for both cannon and mg's in the B wing hence the need for exhaust augmentation for the outboard guns.

As far as I'm aware, the exhaust gun heating was only fitted with a B wing on Spitfires, ref Edgar here

The pipe can be seen here on AN*V

and compare SN*M with exhaust gun heating to SN*V without here

 

  • Thanks 1
Link to comment
Share on other sites

 

 

6 hours ago, Dave Swindell said:

The gun heating tube turns inboard 90deg immediately aft of the exhaust stubs, passing through a notch in the top of the removable cowling side panel. It then turns aft again to the firewall, down the firewall to the spar mounts, then outboard in front of the spar. The pipe splits and vents through the spar into the two 0.303 gun bays. Note the cannon heating was provided through the ducting from the radiators previously used for all 8 0.303's on the A wing, this was insufficient for both cannon and mg's in the B wing hence the need for exhaust augmentation for the outboard guns.

As far as I'm aware, the exhaust gun heating was only fitted with a B wing on Spitfires, ref Edgar here

The pipe can be seen here on AN*V

and compare SN*M with exhaust gun heating to SN*V without here

 

 

Was this on both the Spitfire and the Hurricane? As the Hurricane had all it's guns ( except for Mk.IIB's ) grouped in a single bay in each wing, would it have needed additional bay heating?

 

 

Chris

  • Like 1
Link to comment
Share on other sites

16 hours ago, dogsbody said:

Was this on both the Spitfire and the Hurricane? As the Hurricane had all it's guns ( except for Mk.IIB's ) grouped in a single bay in each wing, would it have needed additional bay heating?

 

Chris

Not sure on the Hurricane, Chris, I'd have  to look that one up.

Off the top of my head though, your logic seems good with 2 cannon in the C wing replacing the 4 0.303's in the same compact bay you'd think the original heating would be sufficient.

The 12 gun wings, however, with the extra 0.303's further out on the wing, might have needed augmented heating via the exhaust.

  • Like 1
Link to comment
Share on other sites

Hi all

While on the subject of warm air for gun heating, all the 1/48 kits of Mk 1 Spitfires fail to add the gun heating air exhaust vents that are just outboard of the outboard gun spent shell ejector ports. I notice the new Tamiya Spitfire also misses these out, however they are on the old 1/48 Tamiya Mk Vb Spitfire. Even early Mk 1 Spitfires fitted with the two bladed Watts propellor has these vents so any WW2 build will need them.

 

Bob

  • Like 2
Link to comment
Share on other sites

Hmmm, after looking through several Hurricane books I can't find a single photo of a Hurricane with gun heating tubes through the exhaust, I rather suspect this was a Spitfire only fitment. The other types of exhaust stubs were used on both Spitfire and Hurricane.

  • Like 1
Link to comment
Share on other sites

2 hours ago, Retired Bob said:

Hi all

While on the subject of warm air for gun heating, all the 1/48 kits of Mk 1 Spitfires fail to add the gun heating air exhaust vents that are just outboard of the outboard gun spent shell ejector ports. I notice the new Tamiya Spitfire also misses these out, however they are on the old 1/48 Tamiya Mk Vb Spitfire. Even early Mk 1 Spitfires fitted with the two bladed Watts propellor has these vents so any WW2 build will need them.

 

I was under the impression that the new Tamiya kit has these as separate (optional) parts.  Airfix did miss them on their most recent I/Vb, unfortunately.

Link to comment
Share on other sites

Hi Tbolt

 

Had a good look at Brett's video, cannot see any vents on the underside of the wing, or indentations to fit them if they are separate items.

 

Bob

Edited by Retired Bob
Forgot to add my name.
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...