How do I work around this?

[ozarkgem]

I have been sawing some Sycamore for my next building project. As I get close to the pith its starts to split. These were dead standing but still green inside. About 2" outside were "Spalted" so they made slabs. I would like to get as many boards as I can but don't want to waste time on sawing something I will throw away. Also I cut a couple of 20" wide board off the outside and put them on the bottom of the stack. What will they do? Split? It is an experiment for me.

  

 

[Magicman]

Looks like you may have some undetected ring shake.  If so, the split was already there before you sawed.  Look closely at the butt and orient the face openings to avoid it. 

Sometimes it is kinda like sawing two logs.  One outside the shake and one smaller inside, with the balance being split and shelled lumber.

[Ron Wenrich]

Shake is common in sycamore.  A lot of times you can't see it until you cut the board.  Where you see those dark rings, there might be shake present. 

Wide boards can always be a gamble.  Keep stickers at the end of the boards to help prevent splitting.  But, there are no guarantees.

[ozarkgem]

I noticed some of the split happened as soon as the blade exited the log. Kind of cool really. Perfect board then instantly a split.

[ozarkgem]

Looks like you may have some undetected ring shake.  If so, the split was already there before you sawed.  Look closely at the butt and orient the face openings to avoid it. 

Sometimes it is kinda like sawing two logs.  One outside the shake and one smaller inside, with the balance being split and shelled lumber.

So looking at the butt crack how should I have opened this one?

[customsawyer]

Don't get your hopes to high. Flat sawn sycamore does not behave well.

[ozarkgem]

would 1x6's be better. I am looking to panel my next house with it. How about sycamore  car siding?

[Magicman]

So looking at the butt crack how should I have opened this one?

Take the side lumber off down to the shake and then saw the center as a separate log.  Yes, you will be challenged to get it to dry flat.  Do some close stickering.

QS is always the best option with Sycamore, but not so much with that particular log.  Too much loss.