buelladdicted
Well-known member
- Joined
- May 8, 2009
- Messages
- 196
the most important factor that determines rpm, peak HP,torque etc.is not really size of parts,or degree of v configuration,altho they all contribute.The relation of bore diameter to length of stroke matters the most.There are several reasons and I will generalize,leverage,friction,balance,larger bore allows larger or multi valve configurations per displacement.there is no one factor that determines power curve or rpm capacity more than this.when a motor is square, stroke is equal bore diameter,when its over square bore diameter is greater,when under square like our 12s stroke is greater than bore.xb9s are over square and thus the rpm difference and more peak hp per displacement,1125 ,more over square,more rpms,and much more hp,and the much more,comes from optimizeing all the above mentioned factors.The fact that our 12s make the hp they do along with the torgue is why I like it.When it comes to motors you cant really have it all,but my xb 12 comes close for my preference.