I have learned never to be sure of anything.
At one time, to get a 4.0cc engine, I mounted a short stroke 3.5cc crank in a large stroke 4.6ccengine, deviding the stroke difference top and bottom. This gave just 95° transfer, but with good port width. Exhaust was about 140°.
The engine had very good large prop (10x4) pulling properties from 12,000 upward, yet would rev up happily upto 19,000against all expectations. Not with all the power that one would expect from it's displacement, but there just seemed to be no upper rpm limit when the prop unloaded. Now this timing would not have been first choice, but it worked sooo well. The large blowdown surely helped rpm a lot.