Trying to ID a aero engine valve

[GTiRichTea]

Just searching for this valve i have which was my uncles just wondering what is came out of.

Edited by GTiRichTea on Friday 28th October 10:07

Edited by GTiRichTea on Friday 28th October 10:17

[Simpo Two]

I have a Merlin inlet valve and the face diameter is about 1.9".

So either the exhaust valve is bigger or it's not from a Merlin IMHO.

[Eric Mc]

Griffon?

[pherlopolus]

it looks similar to the Merlin one my granddad was given for his efforts as a machinist during the war. I'll try and measure it when I see my parents at the weekend.

[jjones]

what a lovely pairing of objects

[Mojocvh]

Imperial needs to be tied with fractions not decimals.

It'll also make matching it to era drawings simplistic.

I also have one of those digital callipers from china

Edited by Mojocvh on Wednesday 25th September 19:21

[Gokartmozart]

Possibly slightly too large for a Merlin according to page 18.

http://www.enginehistory.org/members/articles/Slee...


Page 316 gives inlet and exhaust throat areas for the Griffon 65
which you could work out for yours.

http://www.spitfireperformance.com/griffon-65.pdf

[Gokartmozart]

Possibly slightly too large for a Merlin according to page 18.

http://www.enginehistory.org/members/articles/Slee...


Page 316 gives inlet and exhaust throat areas for the Griffon 65
which you could work out for yours.

http://www.spitfireperformance.com/griffon-65.pdf

[Simpo Two]

Gokartmozart said:

Page 316 gives inlet and exhaust throat areas for the Griffon 65
which you could work out for yours.

http://www.spitfireperformance.com/griffon-65.pdf

p315.

Inlet 5.54 sq.in.
Exhaust 4.12 sq.in.

Using pi x D to get from area to diameter I make the diameters 1.76" and 1.31" respectively... so either I have misinterpreted something or I have the valve from something even bigger and the OP bigger still...

But then, if 'throat diameter' is the diameter of the actual inlet, the valve will be larger... which might explain it.

[Krikkit]

Simpo Two said:

Gokartmozart said:

Page 316 gives inlet and exhaust throat areas for the Griffon 65
which you could work out for yours.

http://www.spitfireperformance.com/griffon-65.pdf

p315.

Inlet 5.54 sq.in.
Exhaust 4.12 sq.in.

Using pi x D to get from area to diameter I make the diameters 1.76" and 1.31" respectively... so either I have misinterpreted something or I have the valve from something even bigger and the OP bigger still...

But then, if 'throat diameter' is the diameter of the actual inlet, the valve will be larger... which might explain it.

Throat diameter is the area which the gas can flow through- the valve has to be bigger than this, because the whole throat diameter must be completely sealed when the valve is shut. Measure the back of your valve to see the diameter between the edges of the seat on the stem-side, that should be ~throat diameter.

The OP sounds like he has something a bit bigger - even the exhaust valve of a Griffon won't need 0.5" for the sealing of a 2" valve.

[GTiRichTea]

Thanks for the info i will take a look at what has been said, and measure it again.

[Simpo Two]

Krikkit said:

Throat diameter is the area which the gas can flow through- the valve has to be bigger than this, because the whole throat diameter must be completely sealed when the valve is shut.

Gotcha. Ignorance + intelligence can be an enlightening mix!

[dr_gn]

Bristol Pegasus is my guess.