Does anyone have any pictures or drawings detailing the addition of a 9th or 10th stud to an engine? For clarity I'm not meaning pictures of original 10 stud blocks, rather the solutions devised post war!
I presume you're not counting the extra 9th stud you can get with a 3 bearing crankcase.
I did build one engine with an extra 5/16" stud front and back using the front camshaft bearing retaining thread and an equivalent new tapped hole over the rear camshaft bearing. Tapping through into the front camshaft bearing firmly rooted that one and a long stud (shortened brake pedal rod) with a nut sealed to the crankcase formed the extra stud. I had a flat head face with a Z shaped bracket on the two front studs. This extra stud was torqued down after the normal sequence with a lock nut applied under the Z bracket. There's enough meat in the equivalent position over the rear cam bearing to get a second in there. I have heard (but not seen) of L shaped brackets being bolted and bonded onto the front and back of the block for a similar intent.
I also remember that one of the side valve works car had thread problems in an 80's (?) rebuild. The solution was to make a larger tappet chest cover, structurally fix it to the block and bolt across into the crankcase.
Mine seemed to work all right but the engine had a demise in a different direction and I haven't any photos. I see however from their website that Pigsty have independantly come up with a similar idea.
I'm building a 3 bearing engine at the moment and other than the extra centre bearing stud and sticking qualities of Loctite 518 I've decided this engine doesn't need the extra two studs.
I have an engine which came in pieces which was converted by Richard Hutchings.
It was a blown ulster conversion 10 stud block on magneto crankcase.where the extra studs tap into the block bosses had been welded inside the c/c.The front and rear of the 8 stud hole pattern needed to be blanked off,sorry no photo's.
The welding for the s/c mounts and these extra top studs distorted the c/c so wouldn't try this way.
I don't believe the 10 stud block idea on an 8 stud crankcase is a very good one,the next problem being,in my case,one of the "new" stud holes happens to be tapped into the front camshaft oil gallery so its got 60 psi behind it and have spent a lot of time trying to seal it insitu.
Robin Jackson I think post war fitted blocks or angle brackets to the tappet chest side of the block to hold it down,The strongest part of the crankcase.