The engine might be 110cc...
That engine may only be 110cc. My Honda XR80 engine (with 80cc vertical cylinder) is roughly 16" tall due to its ohc design. This engine barely fit in my Silver State Cycles board track frame. The XR100 is nearly an inch taller and you still need space for valve adjustments.
Either way, it may be hard to find a frame which will support such a tall engine. You're probably going to have to custom-fabricate one. Honestly, I would consider foregoing the top bar altogether.
To put things in perspective, the CG125 engine is around 14" tall since it uses an OHV design.
Good luck! If your engine is a 110cc OHC screamer, you've got a lot of power on your hands. Probably close to 9hp stock. My XR80 can hit 10,000 rpm stock (12,000 rpm modified).