289 vs. 302

Ron1 · 03-10-2002, 11:34 PM

The benefit of stroking an engine lies in the amount of torque the motor will produce. Torque being that ,which gets then car moving down track. The point in the RPM range where peak torque is developed and the point where maximum HP is developed, are dictated by how the displacement is built. As the stroke increases the lower in the RPM range the peak HP and torque will occur. However, a longer stroke motor will produce less peak HP but more peak torque. Short stroke engines produce peak power levels at a higher RPM and can produce a higher peak power, but less torque. You have to make a decision on how your motor will be built based on your vehicle weight, a standard or auto trans, gear ratio's and the rest.
As an example, I race a fairly light car, and leave at a fairly high RPM (5400) , so I do not need a whole bunch of bottom end torque to move down track. (BTW, I can compensate for less bottom end torque by adding something like N2O).
A heavy car, with an automatic for example, needs a lot of bottom end torque to get rolling, if it doesn't have it, it will not perform well.
David Vizard has an excellent book available..."How to build HP" volume 1&2, worth while reading.

Ron

03-10-2002, 11:34 PM	#1
Ron1 Registered Member Join Date: Sep 1999 Location: Vancouver, WA USA Posts: 439	The benefit of stroking an engine lies in the amount of torque the motor will produce. Torque being that ,which gets then car moving down track. The point in the RPM range where peak torque is developed and the point where maximum HP is developed, are dictated by how the displacement is built. As the stroke increases the lower in the RPM range the peak HP and torque will occur. However, a longer stroke motor will produce less peak HP but more peak torque. Short stroke engines produce peak power levels at a higher RPM and can produce a higher peak power, but less torque. You have to make a decision on how your motor will be built based on your vehicle weight, a standard or auto trans, gear ratio's and the rest. As an example, I race a fairly light car, and leave at a fairly high RPM (5400) , so I do not need a whole bunch of bottom end torque to move down track. (BTW, I can compensate for less bottom end torque by adding something like N2O). A heavy car, with an automatic for example, needs a lot of bottom end torque to get rolling, if it doesn't have it, it will not perform well. David Vizard has an excellent book available..."How to build HP" volume 1&2, worth while reading. Ron