OK I see,I was wondering how they'd do it. Your idea should work too,I don't know how much you can hollow out the rod big end pin before it breaks,I figure there's a lot of load on it at 13,000. I wouldn't worry about the "balance" too much,2-stroke singles aren't really balanced at all it seems,I've changed the weights of things(Like much heavier piston) and they have stayed together at full speed.
As for the titanium cranks the magnesium was harder to find than high strength titanium. On the "machinability" index titanium is one of the most difficult metals to machine as my machinist found out but it's really strong,I finished the cranks by polishing them too,figuring out how to balance a totally new crank took some thinking but I got it right. The cranks worked really well,ran smooth and boosted power by the substantially higher crankcase compression ratio,and of course because the hole for the rod big end had to be machined into the crank's flywheels I could basically choose where,for the stroke length,I only stroked it 2mm to keep them under 100cc.
The first time I put one of those cranks in a saw and revved it up,I kinda held the saw at arm's length,I wasn't sure if the whole thing wouldn't blow up,but they were fine.
I had some leftover titanium and made a few small experimental parts,one- a titanium wrist pin was half the weight of stock,but not a HARD enough material,I put one in a used 064 and sent it out for a weeks work with a faller to test it,he brought it back and it never broke,but when I took the wrist pin out it was incredibly worn!!
