I'll take the extra 80cc's at 11:1 anytime. Adding motor size is the absolute easiest way to gain hp and tq. The reason I put carb and pipe first is because the stock carb isnt big enough to efficiently feed the stock motor and the stock exhaust flows too slow below 5000rpm.

 

There are so many variables involved, that I'm confident that none of us could list them all. Cam timing is one of the magor factors, meaning that the same cams installed at a slightly different phase, will change the tq/hp curve.

There are NO constants, but one generaly accepted rule of thumb, the longer the stroke will create more torque for a given displacement. A short stroke/ big bore motor, of xxxcc's, will not have the same TQ of a small bore/ long stroke motor of the same displacement, although it may make more HP. [this example is provided all other factors are =]

 

I do apologoze to those who cannot stand the mathmatical parts to all this, but this is where the picture become clearer for me is playing in the total numbers games. Knutz and OMR I would love to just sit with the two of you and blow this around for a few days. It would seem to me based on my research of what is really done in a motor, and what could be done by a motor are two completly different things. The formulas are the easy part. Plugging in the numbers that are available is also very simple. The variables on the other hand are what I don't have enough information on myself (terminology also hurts me). Why oh why did I not take autoshop back in high school when I had the time for this. So please forgive the ignorance of some of the continuing questions I have.

When you are referring to the stroke...What part is that? What would be considered short and long?

Thanks all!!!

 

"Stroke" is the distance that the piston travels from its upper most limit to its lowest limit.

 

Uh.....Dragon? Did you actually type "Kuntz" in that last post?[img]i/expressions/face-icon-small-happy.gif[/img]

 

Hmmmm, Holly Shnikies [img]i/expressions/face-icon-small-smile.gif[/img] Darn fingers are always hitting the wrong buttons [img]i/expressions/face-icon-small-wink.gif[/img]

 

And what controls the limits?

 

Torque and Horsepower are funny things. Remember back in the '80's when we were all so impressed when a car did 0 - 60 in 7 seconds flat? Two cars that taught me something about torque were the 944 turbo and the RX7 turbo. They both had about the same power to weight ratio and their 0 - 60 times were almost identical (6.3ish). After that is where the torque started to make itself known. Even with very similar power to weight ratio's the 944 would start pulling away. It would make it to 130 almost 10 seconds quicker. The little rotary mazda motor spun up so quick to such a high rpm equivelant, it made lots of horsepower at a very low relative engine speed. This gave the perception of a high torque motor. It had about half the displacement of the 944 so in reality it did post much lower torque numbers but they didn't show up until the motor was trying to push a certain amount of weight in higher and higher gears with increased wind resistance.

Typically we think of torque in terms of bottom end and horsepower in terms of top end. If you change the perspective and look at bottom end as 1st and 2nd gear, it is mostly the horsepower you feel making you go fast because you don't need that much torque in the first two gears. If you look at 4th and 5th gear as top end, it will be the torque that will impress you as higher torque will continue to make lots of power in higher gears where the load on the motor is much greater.

The real advantage to high torque numbers is when you get into the upper gears where horsepower is made more slowely due to increased load that slows rpm acceleration.

 

So as to not torque any of the more "experianced" people on here, lets just say I was a bit too young to know what of much that happened in the 80s [img]i/expressions/face-icon-small-wink.gif[/img]

The better torque at the top end absolutly makes since, and I want to create myself a ride that has the best of both worlds. I understand the ending factors, but for me it is like a clock. I can look at the clock and know what time it has, however I have no idea what really makes it tick. I think it has to do with the tocks, but could be wrong [img]i/expressions/face-icon-small-smile.gif[/img]

Same problem with motors. I know what they do, and I know I like them fast....I just don't know what makes it tick?

 

And what controls the limits?

The length of the rod and the offset of the crank.