Hi!
Correct me if I´m wrong but I think comparing twostroke and fourstroke engines of similar size then the the twostroke both has more hp and torque!!??
The reason for chosing a fourstoke engine before a twostroke has to do with sound ...not that the foustroke is more powerfull or has more trust!
Most modern twostrokes will outperform a similar size fourstoke engine ...both when using a big prop at slowspeeds and naturally when using a small prop att high speeds.
Let me take an example. I have several OS .26 fourstokes (open exhaust) and they all rew appr 10000 on a 10x5 Scimitar Master airscreew prop (5% nitro and 15% Motul "Micro" all syntetic oil)
Comparing that with my MVVS .28 (same fuel as above) using the MVVS super quiet silencer which rew appr 11000 on a 11x4 APC which gives much better performance and quieter sound than the fourstroke in the same airplane.

Regards!
Jan K
Sweden