LOL, Nah man. We could gusset is up and you would be set. [img]i/expressions/face-icon-small-wink.gif[/img] I think I just might carry mine for a dune ride with all that torque mine made....[img]i/expressions/face-icon-small-tongue.gif[/img]

 

2big asked an interesting question. I am guessing here because I have never thought of that before but I think only rotational resistance (rotating mass, friction, gearing leverage & tire size) would create a difference between torque at the crank and torque at the rear wheels. I think added dead weight would only effect the torque's ability to rev the motor and create horsepower, not the amount of torque that is already being made at the rear tires. The motor only makes so much torque, minimizing rotating mass and friction maximizes how much of the motor's torque you get to use for performance. That is my first thought but I could definitely be mistaken![img]i/expressions/face-icon-small-wink.gif[/img]

 

That is what my research has led me to understand.

 

I have always thought that any variables outside of the engine itself (sprung or unsprung weight, drag etc) though having a great effect on the overall performance of the machine and its requirements to reach a certain speed or rate of acceleration etc had no effect on the output of the engine itself.

So an engine producing 50hp and or 50lbs of torque will produce the same amounts with a 100lb rider or a 300lb one, but the power required to push the machine with the heavier rider will be higher than the one with the lighter rider. This is why we see power to weight ratios mentioned all the time in racing, and all the light weight aftermarket parts.

Far as I can see DSNUT had it right.

I am not the authority on this stuff, but I really think except for drag racining (and sometimes true for this too) most riders have enough power after doing basic intake and exhaust mods, and would see better results from getting in shape, losing weight, and practicing, practicing and practicing more to improve their skills.

Still were talking about torque here, and the more your machine and you weigh the more of it your going to need.

Not sure if any of you here have seen some of my posts in the past on my prefference for bottom end grunt (torque) over top end HP, but I think I have made more than a few laugh since I am kind of a torque junkie. Even though this engine I have in my atv is more restricted than many in its ability to handle additional power due to being air cooled etc I had specifically set it up to produce more bottom end than top end, and have still crossed the line and had to make repairs or updates to handle it. Even when I was into spending lots more $$$ and built muscle cars I had passed on the high reving small block chevy engine in favor of the big block due to its being a potential torque monster.

Last thing that comes to mind is all the variables internally in the engine that can effect the amount of torque it produces (hp also) and though it seems most have been touched on already I have been looking also looking into the comparisons of cam and ignition timing, and also velocity v volume as they are seem to effect how the power is made too.

Without the proper equipment and $$$ to perform proper testing it really seems we are all sort of limited to a degree and will have to continue to rely on our own experiences and the input from others with more knowledge etc, but hey learning and experimenting is a big part of what makes this all so much fun.

 

OK so does more displacement or compression create more torque?? Yea h I know carb, and a cam's and head work also help.

 

The compression will increase torque. I dont know on the others.

 

The swing of the crank is the only factor that changes stroke. Rod length has nothing to do with stroke, but is often incorrectly thrown in as a factor. Moving the crank pin further from the crank center line will increase stroke, closer to center will decrease stroke.

Both higher compresion and bigger displacement will increase torque; each of them rely on many other factors to determine if they help torque or HP more. Given all factors remaining the [relative] same, compresion will increase HP and TQ about the same. Displacement is dependant on if the stroke or the bore is increased to gain the displacement.

 

Wow, brain overload on all of this. But pieces are starting to slide in to place. I have soooo much tolearn yet.

 

Dont worry it will get easier as you start to pick up some of it etc, at least it made it easier to be less confused for me lol.

 

Knuts,

I know you are an expert on this stuff. I will not even dream of arguing with you on the stroke thing but I would like to know where I went wrong. I mentioned rod length in conjunction with crank offset or throw for the following reason:

Lets say you have 4 mil of clearance between your valves and your piston at their closest point in a revolution and you want to do an 8 mil stroker. If you increase the crank throw by 8 mil, it seems as though you would cause the piston to travel 8 mil further at the top as well as the bottom of the throw. I guessed that this would cause the piston to conflict with the valves. I then assumed the way to get an 8 mil stroke increase would be to only offset the crank by an additional 4 mil and shorten the rod by 4 mil. It seemed to me like this would give you a full 8 mil stroke increase at the bottom of the piston travel but the piston would come up, theoretically, to the same point at the top as it did before maintaing a suitable valve clearance.

Please forgive my ignorance, I build houses for a living and am just learning about small engines. I am only guessing on this.

Ron