Valve identification help

Member for

5 years 4 months

Posts: 17

It all started with a couple of random valves I purchased on the off chance that members of this forum kindly identified for me as merlin items now my collection is starting to grow and numbers over 40, but I am puzzled with a group that I have that all look similar to the merlin ones but at the same time are all different sizes so I am wondering if anyone on here might be able to tell me if they could be from the same type of engine but modified over the years of production or from different types engines from the same manufacturer or completely different manufacturers and just coincidently look alike

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Member for

5 years 4 months

Posts: 17

I also have this one which puzzles me- I have never seen a valve like it before, can anyone shed any light on it ?[ATTACH=CONFIG]237235[/ATTACH]

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Member for

5 years 4 months

Posts: 17

[ATTACH=CONFIG]237237[/ATTACH]

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Profile picture for user MerlinPete

Member for

13 years 11 months

Posts: 1,270

Hi Arejay. The larger valves in the group are probably Griffon, but you would need to give the size.

Shielded valves are a feature of some Diesel engines with pre combustion chambers, I haven't seen them
In a aero engine. Are you sure they are aircraft, any numbers visible?

Pete

Member for

5 years 4 months

Posts: 17

[ATTACH=CONFIG]237270[/ATTACH]Hi pete, I have measured the valves as best as I can and here are the results, all measurements are in mm
Valve A Length 123, stem dia 11, Head dia 48, Head thickness at edge 4
Valve B Length 123, stem dia 14, Head dia 45, Head thickness at edge 5
Valve C Length 125, Stem dia 11, Head dia 48, Head thickness at edge 7
Valve D Length 142, Stem dia 13, Head dia 53, Head thickness at edge 8
Valve E Length 139, Stem dia 15, Head dia 51, Head thickness at edge 6
As for the odd valve that you think is from a diesel – i do not doubt you for a second, I was led to believe that it was from an aircraft but as I have not yet amassed much knowledge on the subject I am easy prey for traders- my only gauge on buying them is basically I look for valves that are as big as or bigger than the merlin ones that I've got- probably foolishly it appears but i assumed that an average diesel engine would not have valves as big as a large cc aircraft engine ! however on the positive side- apart from the two original valves that I had I’ve not paid more than £1.30 for any one of them and it looks like a few may be good ones so I’m not too worried if others are not what I had hoped for. Thank you for your help and advise

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A + B seem to be the same size as the two Merlin valves sat on my desk, but Merlin Pete is your man.

Profile picture for user MerlinPete

Member for

13 years 11 months

Posts: 1,270

Hi Andy!

Arejay, Valves D and E are Griffon, and C is a later style thicker inlet valve for a Merlin.

Pete

Member for

20 years

Posts: 37

I have a valve complete with springs from a Merlin from Mk1 Hurricane or Mk5 Spitfire) head diam 62mm, stem 11mm, length 134mm, is it inlet or exhaust from what Mark Merlin?

Member for

13 years 4 months

Posts: 9,690

Sounds a little big for a Merlin; remember you'd need to fit four valves into the 137mm bore of a Merlin cylinder.

Can you post a photograph?

Profile picture for user MerlinPete

Member for

13 years 11 months

Posts: 1,270

Sounds a little big for a Merlin; remember you'd need to fit four valves into the 137mm bore of a Merlin cylinder

Steady on old chap, it`s 5.4", we don`t want any of that German metric rubbish associated with Rolls-Royce`s finest!
Agreed, it is too big for a Merlin, they all had the same basic valve dimensions.

Pete

Member for

20 years

Posts: 37

Whilst searching for something else today in my "archives" it seems that it is an inlet valve from a Dornier 217 BMW 801 engine, I also have a bent hollow (was sodium filled) exhaust valve, head diam 68mm, stem diam 16mm, photos to follow later.