By: Creaking Door - 21st October 2011 at 00:39
There are some inspection stamps but they are difficult to read as my piston hasn’t been polished; I’ll see if I can make them out.
By: MerlinPete - 18th October 2011 at 07:10
Clearly the part number has been machined off the ashtray then.
CD, you are right on all those points, but I don`t know about the “CON” number. That`s not something which I have ever heard of.
IN is indeed an orientation mark meaning inlet.
Does it have any inspection stamps? I wondered who the maker was.
Pete
By: Creaking Door - 17th October 2011 at 23:03
I have a similar piston, also reputed to be from an 8 Squadron Shackleton, although not anything like as well presented!
Does anybody know for sure what the ‘IN’ stamped into one edge of the crown means; I’ve always assumed it stands for ‘INLET’ (valve), to indicate which way round the piston should be assembled onto the crankshaft, the inlet valves being towards the centre-line of the engine.
The other markings on mine, other than ‘GN26948’, are ‘4-7-0’, which I take to be the weight in pounds, ounces and drams, and ‘6-1’, which I take to be the compression ratio for the Griffon.
Also stamped on the underside of the skirt is ‘CON 484 SY’, presumably to do with the connecting-rod?
By: Al - 17th October 2011 at 22:38
Here’s some images of a Griffon piston from an 8 Sqn Lossiemouth Shackleton AEW.2 which threw a rod in the early 1980s.
It measures 5 15/16″ across with a school ruler, and has many stamps on it, including ‘GN26948’ below one of the pin bosses…
By: MerlinPete - 17th October 2011 at 21:16
The serial number appears to be 336C155598. On the opposite side is a marking that looks like ‘B6’
Does this narrow it down any further?
You need a GN prefixed number to narrow it down, but that was probably on the part which has been removed. I agree with CD that it is an earlier type, but that doesn`t necessarily mean it wasn`t from an earlier Shackleton engine.
B6 is the position of the piston in the engine.
Pete
By: --o-o-O-o-o-- - 17th October 2011 at 20:53
The serial number appears to be 336C155598. On the opposite side is a marking that looks like ‘B6’
Does this narrow it down any further?
By: Creaking Door - 14th October 2011 at 00:55
Very nice! 🙂
Does anybody know if it possible to say what mark of Griffon, or even what type of aircraft, this piston would have come from? I’ve come across two basic types of Griffon piston, the one pictured, and one with a shallower, wider ‘bowl’ in the crown and with a distinctive ridge down the centre of the underside of the crown.
Not knowing any better, my simplistic view says that the pistons with the ridge inside are from a Shackleton and the piston pictured is from a Spitfire (or Firefly)…
…but it can’t be that simple! :rolleyes:
By: MerlinPete - 13th October 2011 at 20:58
Griffon
I don`t think it`s a piston, it looks more like an ashtray to me.
Pete
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October 13, 2011 at 6:51 pm