A7 or A10 head/valves

[Brandis]

I hate to always reveal myself to the one that knows less about this stuff than Liz Truss. . .
AND . . .
The Forum is fussy tonight and won't let me upload a photo.  I have 2 heads. One has the intake manifold cast into head.  I assume it's for an A10.  The other has separate intakes and a alum. manifold.  I assume it's an A7. 
If so, I have new valves for an A10.  My parts book is travelling here by dog sled so I can't check #s. .  Are my new valves also the right ones for my '47 A7?

There are so many quirks and changes within the '47 A7 model year.

[Swarfcut]

 In a word ...NO

  Valves for the Longstroke are unique to that model, as is the cylinder head casting. The Longstroke jug has  a raised locating spigot at the top of each bore. The head casting is recessed to take these. Good chance the alloy manifold one is the head you need. Cast on manifolds are the later design.

  Standard bores... Longstroke bore is 62mm, later A7 bore is 66mm, and A10  at 70mm so a quick measure across the combustion chamber tells what's what.   67-25 is the casting number on the Longstroke A7 Head, look on top fin, by left spark plug.  Later design have it on underside of inlet manifold.

   The heads all have numbers cast into them. These identify the casting, not the part number, which is one or two final digits different. This confuses folks, especially when identifying pistons. The part number refers to a complete assembly in these cases. All will come clear when your parts book is to hand.

 My researches indicate Longstroke Valve Stems are 5/16", Inlet valve 1 1/4" head, Exhaust 1 3/16" but as always, check these from alternative sources.

   Standard Longstroke inlet valve is part 67 29, exhaust 67 30. Spring seats, spring cap, collets and inlet guide (also used as exhaust  guide on later engine) are the same, so valve stem diameter looks to be common. Valve springs are different but some folks fit standard later iron head springs which work OK. Rocker spindles and shaft washers are the same as later engine, everything else is different.

 Swarfy.

 Additional.    Drags Valve  Chart             Inlet Valve Part 67 29     Exhaust  Valve Part 67 30

                                            Stem        0.310" /7.9mm              0.309 /  7.8mm

                                            Head        1.359" /34.5mm            1.281 /  32.5mm

            "Back of seat to end" Length      3.781"/ 96mm               3.344"/ 84.9mm

[Brandis]

They sure look like they fit.  Intake and exhaust are the same dimensions. And there are no locating spigots to be found.  Head and barrel planed flat. 
Remember, BSA did a bunch of messing around in the first 500 units be fore they realized that they had to shut down engine production to solve the glaring problem, whatever that was.
The Forum won't let me attach a photo.  Let me try it it in a separate post.

[Swarfcut]

   Looking back thro' previous posts, the illustrations from contemporary magazines and reports show the head and barrel join with the raised spigots. They are shown in cutaway on page 37 of Roy Bacon's Twin Restoration which also shows the valve gear and characteristic two rocker boxes.
 
 So, a mystery for now as to what you actually have. Keep working on those pictures.

 Swarfy.

[Brandis]

Well I seem to have the engine shown on page 37 in Roy's book.  I've fitted a lot of valves in bikes, cars and industrial diesels over the years.  The diameter of the exhaust and intake valve heads look like a perfect when seated.  And when I fit the rocker arm, the intake valve stem length looks good.  The exhaust valves, however, are too long. 

I guess I'll make this into a Draganfly or Kidderminster problem.