This isn't nearly the mystery you make it out to be. TORQUE X RPM / 5250 = HP
So horsepower is dependent on two things, torque and RPM. The reason many honda engines produce "bigger" HP numbers than torque numbers is because they maintain peak or near peak torque at higher RPM. High RPM X Good torque = more HP.
So your question is absolutely valid but the way you asked it could confuse future readers of this thread. The ratio of torque to HP is fixed. The ratio of PEAK HP to PEAK torque is what you are interested in.
Generally longer stroke engines tend to produce more torque lower in the RPM range. These engines "pull" harder down low and in the mid-range. But a long stroke limits the safe limit on RPM because it means more mass moving at faster peak speeds. A shorter stroke engine can rev higher, all other things being equal, but it tends to produce less torque and peak torque tends to be higher in the RPM range. This can be a good thing if you want a high-winding engine like the B16 of the 99-2000 Civic Si or the crazy F20C S2000 AP1 engine that could spin safely to over 9K RPM.
Since HP is a function of torque AND RPM, as long as you can wind an engine out to a higher RPM, you can produce more HP with the same amount of torque.
There's obviously a lot of other factors in determining the torque curve and maximum torque of an engine like breathing, as Logic pointed out. That's why the NSX has a variable volume intake plenum and why VTEC was invented.