Merlin Exhaust Temperature?

Pounds yard at Portsmouth had quite a lot of Sea-Lions up to about 10 years ago, with the exception of one or two, I don`t know where they all ended up.
He was only asking £2500 each.

Pete

If I knew then, what I know now…. used to play around that area when my dad was a Chief Gunnery Instructor at Whale Island. This would be between 1966 & the late ’70’s….
Used to look over at Pounds while picking up spent bullets by the bloody bucket load on the beach at the North end of the island… That grey mud on the beach must be about 75% lead….:eek:

Hi all,
Many thanks for the various Napier Lion bits, this is just me idly dreaming about the possibility a flying Supermarine S.5.

Now that there is either flying, or under rebuild an example of most of the main marks of Spit. A Supermarine Schneider racer would be nice addition to the portfolio of one of the more well healed operaters!

Kermit has a lake large enough for a Sunderland.. so…;)

Would really like to see a S.6 belting around the Solent, but getting an Rolls Royce ‘R’ a bit of a problem!

Use a Griffon 🙂

& as for the exhaust stack question:
Quite a few of the Reno guys coat their stacks with JetHot ceramic coating.

Hi all,
Many thanks for the various Napier Lion bits, this is just me idly dreaming about the possibility a flying Supermarine S.5.

Now that there is either flying, or under rebuild an example of most of the main marks of Spit. A Supermarine Schneider racer would be nice addition to the portfolio of one of the more well healed operaters!

Almost anything is possible airframe-wise if enough money is thrown at it, engines though a different matter. Would really like to see a S.6 belting around the Solent, but getting an Rolls Royce ‘R’ a bit of a problem!

I guess I should lay off the Brandy and stop dreaming!!

Cheers, Chumpy.

There is a chap in Derbyshire who has a Lion in his garage which he occasionally runs, much to the annoyance of his neighbours 😎
He also has a Bentley chassis with the intention of putting together a period racer.
Pounds yard at Portsmouth had quite a lot of Sea-Lions up to about 10 years ago, with the exception of one or two, I don`t know where they all ended up.
He was only asking £2500 each.

Pete

This is the kind of thing which makes forums well worthwhile – thank you all.

The only Napier Lion that I know of that runs is in a vintage racing car!

Not much to go on I know but it may help you out.

Here is some video of the Napier Lion in the Bently-Napier racer. Nice sound.
http://uk.youtube.com/watch?v=XmqiTmTuGdA

PS..Going off at a tangent here, does anyone have a Napier Lion..Schneider Trophy style, that runs??

The only Napier Lion that I know of that runs is in a vintage racing car!

Not much to go on I know but it may help you out.

Pete,
Wow what can I say, never imagined that my question would be answered in such fashion! An amazing bit of R&D work on your part, just had a look at your website and am very impressed. Great to see the Alex Henshaw bit, one of my all time heroes.

Must admit that I thought things would be a lot hotter. I can now move ahead with a decent level of confidence, when it comes to the Metallising. This by the way will be done by a specialist company who know what they are doing!

For those not familiar with the process this involves special kit ( basically a gas torch with a hollow nozzle, fed with wire MIG welder style) that sprays molten metal on to the surface of the component. The basic process good up to about 400-500 degrees c.
The process used on exhaust system parts is sometimes called ‘Aluminizing’, the wire used being aluminium. Once the molten spray leaves the nozzel of the gun it rapidly cools and solidifies on the surface of the part being coated, this coating being around 7 thou thick (0.007″).
Following this the part is then coated with a special paint soloution and baked in an oven at around 800 degrees c. This ‘alloys’ the ali / solution on to the surface of the steel shrould and is good for temperatures up to around 950 degrees or so.

So a million thanks, glad that you had fun in the process, reckon I owe you a pint!

Cheers, Chumpy.

PS..Going off at a tangent here, does anyone have a Napier Lion..Schneider Trophy style, that runs??

A bit inconclusive really.
The engine I tested has Lancaster flame damper stubs, and they seem to cool the gases quite effectively, the temparature drops very quickly as you move 4″ or so away from the outlet, about the distance the shroud would be fitted?
I got 300 degrees C at 2650 rpm / -4lb and 420 degrees at 3000 rpm and zero boost. This was the point at which I was in danger of being blown onto my a-s I`m afraid.
I am sure the temp will go higher than this on boost.
The only thing I do know is that the visible flame with these stubs on that engine never progresses as far as the shroud would be, so it has to cope with a hot gas stream rather than a direct flame playing on it.

If you have a metallising process that can stand 650 degrees I would have thought that was adequate.

Sorry, not much help I know, but I had fun doing it all the same!

Pete

😀 😀 😀

Merlin exhaust

Hi all,
Many thanks for the input on the subject, interesting figures and comments from all parties.

My reason for asking is that I am involved in the making of some exhaust system shroulds. The finished items requiring ‘Metalising’ to DTD 906 spec, (a protective treatment process). This available in different classes depending on the operating temperatures involved.

Interesting to read Creaking’s coments regarding loss of energy / temp etc. Closest experience that I have had was to act as ballast on the rear end of a MkXIV Spit during engine runs. Pleasently warm slipstream back there, incredibly loud, had a bad hair day, but totally dandruff free…much better than using Head & Shoulders!

Cheers, Chumpy.

That remark about the exhaust flame brought to mind the pictures posted of Spitfire and Lancaster night engine runs posted on here some time ago. Quite impressive to say the least.

At ground idle you can put your hand in the exhaust gas flow (he couldn`t have put his hand IN the exhaust stub, they are too small!) but at higher RPM there is an exhaust flame which can only be seen in low light, accompanied by much higher temparatures.
If you run your hand across the gas flow under power you have to do it pretty quickly, but as Stuart pointed out it can tell you how a cylinder is firing, particularly with long periods of ground running as this fouls the plugs.
I will do some measurements on a Merlin next weekend and post it on `ere!

Pete

Or if the engine wasn’t running on that cyl, which might be why he was checking the exhaust stub with his hand, looking for unburnt fuel/oil etc. (I bet Merlin Pete knows)

Yes, if the exhaust gasses stayed at 1500°C but of course they don’t.

Exhaust gasses loose their energy extremely quickly as they have high temperature but very low mass.

If you touched the exhaust stub you’d burn yourself – much lower temperature but much more of it!

😮 there was a guy at legends with a griffon on a trailer, ground running it, he kept putting his hand in the exhaust, if its at 1500 degrees, shouldn’t it be melting his hand?

The maximum temperature of the combustion in the cylinder will be something of the order of 2200°C – 2400°C with the exhaust gasses at something like 1000°C – 1500°C.

There is nothing particularly remarkable about these temperatures they will be similar for the engine in your car.