The crank is a std A65 we cut in half and bolted up at 90 deg. It makes quite a difference, (more responsive and smoother at revs). The rods are on my longer stroke altered norton crank which is also 90deg, the reason for the bolts screwing into the cap is the lack of space in the crank case.
I want to make a crank like in the photo only with a ballancemaster ring in the centre flywheel, the short stroke 90 is quite smooth but the ring should smooth it more and maybe get it similar to an engine with a ballance shaft but without the weight and performance loss.
Yea I had an old pair of Norton rods I polished and fired one through the cases, should have made mounted it for the wall, it chopped all around even into the gear case, the oil pickup tube was in the centre of the road. These rods are rated for 100HP per rod, so should last for a while with a lot less thumping at them than that.
I met Carey the other day, we were near his place and heard a twin running and so intoduced ourselves. His A10 will be nice when he gets it sorted.