Hi, A while back I took a chance and purchased 3 engine components that were allegedly from aircraft that had been shot down in the battle of Britain, although I am not an engineer and have never worked in the aircraft industry I found them fascinating and thought it would be interesting to research them and try to find out if they were genuine. Two of them were relatively easy as they turned out to be a piston and valve assembly from an early merlin engine. The 3rd is also a valve assembly but as hard as I have tried I just cannot find any information as to what engine/aircraft it may have originated from so I am hoping someone on here may be able to tell me something about it. One thing I noticed is that there is a circlip around the valve stem and although this may be a common thing I have never seen it before, the size of the valve assembly is just a little bit bigger than the merlin. Thanks in advance for any info
By: MerlinPete - 4th October 2014 at 21:02
All those valves, guides and springs are Merlin, yes. The spring top washers are early design, but were used throughout production, likewise the early skirted piston which was fitted to the Merlin XX until 1944.
Pete
By: Creaking Door - 4th October 2014 at 12:12
Definitely a Merlin piston and definitely of the basic type found in a Battle-of-Britain aircraft. Very nice too! 🙂
By: arejay - 4th October 2014 at 11:13
#1[ATTACH=CONFIG]232155[/ATTACH]
By: arejay - 4th October 2014 at 11:12
It never occurred to me that the clip might have been added later but it does seem to be the best explanation so far, as you think the second valve may also be from a merlin I am going to email the Rolls Royce heritage trust to see if they will confirm one way or the other. Here are a couple of images of the piston- initially i decided not put it on here in case you told me it was from a meteor engine or something else completely as I would be a bit disappointed but – I am reasonably sure so here it is, so far the info that I think I have discovered about the markings on the bottom is :- D10952 is the part number, B3 means that this piston was number 3 on bank B (the second row of pistons on the V12, W-Ltd means it was made by Wellworthy ( I read that many of the merlin pistons were in early 1940), 6-1 is the compression ratio, 5 5it is the serial number , 3lbs 0oz 1dms is the weight . maybe you will be able to add to this or to tell me that I have got it all wrong.[ATTACH=CONFIG]232154[/ATTACH]
By: Creaking Door - 2nd October 2014 at 11:17
Ah, I see now! For some reason I couldn’t open the photograph in the first post before now.
I agree; in that position it must have been added afterwards to hold the valve-guide up.
By: Arabella-Cox - 2nd October 2014 at 11:12
That circlip has got to have been added at a later date. All it does is stop the valve guide dropping lower down the stem (a job originally done by the cylinder head). Also the damage that the circlip could do to the engine if if broke away would preclude it ever being fitted to a usable engine.
By: Creaking Door - 2nd October 2014 at 10:34
I’ve seen these sorts of tiny wire circlips on valves before; I think possibly on Merlin valves but I can’t remember where they are on the valve. Between the valve-head and the valve-guide?
I wonder what they are for? I suppose you may want to change a broken valve spring without removing the complete cylinder-block? A circlip above the guide would stop the valve dropping into the cylinder if you were stupid enough to take the collets out without the piston being at TDC, but how could you take the collets out without the piston being at TDC to support the valve anyway? Was this even done on the Merlin?
Nobody would cut a groove in a valve-stem and fit this circlip if it wasn’t there for a damn good reason.
By: Rockhopper - 2nd October 2014 at 10:18
Maybe the circlip was added later to stop the guide sliding all the wall down to the bottom of the valve as Andy suggests.
By: QldSpitty - 2nd October 2014 at 02:35
I concur with Bruce.Looks Merlin to me…
By: racer2_uk - 2nd October 2014 at 00:20
Hi arejay, could the clip have been fitted later to show off the assembly better ?
Andy
By: Bruce - 1st October 2014 at 17:46
Yes indeed – I think they are both Merlin.
By: Creaking Door - 1st October 2014 at 17:06
Merlin engines have two sizes of valves; the inlet and exhaust valves are different sizes. Just a thought.
It would be nice to see a photograph of the piston too.
By: arejay - 1st October 2014 at 16:19
the valve on the left in this image I believe came from a merlin engine [ATTACH=CONFIG]232119[/ATTACH]
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October 1, 2014 at 4:14 pm