Since you asked, I will say that what you said about there being less dwell time at BDC with a long rod setup is wrong. Forget the graph that you posted and look at the drawing. It is physically impossible for the piston to have more dwell time at TDC, but less at BDC. TCD and BDC dwell time will always be 100% equal and a long rod setup will always have more dwell time than a short rod will.

It was also mentioned earlier that a short rod motor would create more power because it pushes harder in a tangential direction and it pushes harder earlier on in the stroke when cylinder pressures are higher. He suggests that a short rod motor would actually be advantagous to a long rod because of this.

In response to this, what was said here makes sense, but these factors do not give an advantage to a short rod motor. Because of the increased dwell time at TDC of a short rod motor, and the fact that it has smaller rod angles, it WILL create more power. The more dwell time you have, the more power is conserved in the crank. This is because the more dwell time you have, the less time you spend wasting power moving the piston vertically. Also, it allows the crank to spin relatively freely, instead of having your rings soak that energy up creating friction against the surface of the cylinder walls. Granted, the short rod may convert more vertical force to radial force for the first few degrees of rotation, but with a long rod, after combustion the piston remains where cylinder pressures are the highest for a greater amount of time. Ideally, cylinder pressures are highest near 20 deg ATDC, and the piston remains in that region for a longer period of time with a long rod. At every following point of the rotation, the long rod has the advantage because the rod angle is smaller. All of this adds up to a higher average amount of force on the crank for every 180 deg of rotation. And then you eat the pudding and its all good. The less you have to make the vertical motion move horizontally, the more power you'll make.

Anyway, the amount of actual gain in power of a long rod setup is not the main goal of a long rod setup anyway. It's just a small side effect because you wont be gaining much. Its main purpose is to decrease the side load on the cylinders.

I don't feel like picking this thread apart anymore though... You get the point . If I came off negatively here, I'm sorry. It's not that it bothers me when somebody posts misinformation on accident. It more bothers me that people read it and accept it as the truth because of who said it... like God himself came down from the heavens and said that short rod motors are better than long rod motors or something lol. I don't like it when people argue with me based solely off of someone else's opinion which is what happened to me last night and got me all annoyed.

Matt
1995 Eclipse GS
2.0L, S16g Turbo, 8 Injectors, 26psi

1998 Eclipse GSX
2.3L Stroker, AEM EMS Converted to Speed Density, FP3065 Turbo, 35psi , and so on...