In general, oversquare engine is the best optimum design for racing car. What about rally racing that might need more torque when accelerating through sand and dirt, uphill road?
You have already mentioned the basic tradeoff. I found the link below to be instructive. It brings in other factors than just RPM and torque. It also mentions "efficiency" as opposed to "power density," where power density would mean maximum horsepower per unit weight. (Note that the ratio mentioned is stroke to bore, as opposed to bore to stroke.)
http://achatespower.com/stroke-to-bore/
Also, this other link brings up more variables, including how well an engine can "breathe." Larger bore promotes faster air intake and exhaust in the cylinders, as well as lower parasitic losses. So as always, there are multiple factors to trade off.
http://rehermorrison.com/tech-talk-53-big-bore-or-long-stroke-which-is-better/
But yes, cars that must operate well at various speeds, one would expect, should give more emphasis to torque, than cars which must operate only at steady high speed. And the lighter the chassis, the more important it is to have high power density.
- Badges
- Science topic