Re: Skyhark 250 spec and info
OK, but remember you asked for the explanation. I'm going to try to oversimplify this. Think about it. The cam in the average 4-stroke was most likely designed for mid-range torque at lower rpm's(6000rpm's max). This usually translates into great low-end torque or an easy-to-ride vehicle because you don't have to search for gears all the time. You could also argue engine longevity. If you put a performance cam in it, you could increase the usable power in the upper rpm range and would have a significant boost in horsepower (usually a significant gain in upper-torque as well). How much more does it cost a company to put a performance cam in an engine versus your typical user-friendly cam when the only difference is the shape/angle of the lobes? I would think not very much. All of these engines are capable. It's just how are they built and for what purpose?
16lbs torque at 6000rpms = 18.3hp
16lbs torque at 8000rpms = 24.4hp
No increase in the power you feel (torque) but you can utilize gearing (You shift later, holding each gear longer.) This is why rpm's are so important for speed.
Now assume you can increase your upper range torque with the cam:
18lbs torque at 8000rpms = 27.4hp
There are a lot of 4-strokes turning 10,000 rpms nowdays and because horsepower is driven by rpm's, the potential is definately there. 28hp at 10000rpms is only 14.7 lbs of torque. Hope this helps.
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