- #1
ssvpv8
- 1
- 0
Dear smart people,
I am not so smart but consider myself above the average mechanic. However i have come across information from highly respeced racing mechanics that i can't make sense of. I have researched this subject for a while and it seems everyone gets it but me
It involves the rotating assembly(fly wheel, pulley, crankshaft,connecting rods, and pistons) on any piston driven internal compustion engine. They say when you replace the pistons of an engine with a different weight piston you must rebalance the crankshaft by machining it on the counter wieght ends. An example is switching from the low compression pistons in my v-8 to an aftermarket lighter alloy high compression piston designed for high compression. They say the counter weight balance balances the weight of the connecting rod and half of the weight of the piston. They also say the resulting imbalance of not rebalancing the crank would create vibrations that would eat the bearings.
This is where I have the problem, to me it seems the crank shaft counter weight should only balance half the connecting rod weight and none of the piston weight as none of the piston weight is spinning. Further more it seems to me the force of the weight on the crank from the piston travel would pale incomparison to the forces of compresing the air and fuel, the exploding air fuel ratio, the almost free travle of the piston pushing the spent gasses out, and the suction of sucking new air and fuel in.
Now like I said. I'm probably not as smart as most of the forum users as i have no education beyond high school. So if I really am thinking backwards, take this oprotunity to flame me I will take it for wasting you time on such a large post. I may also cry a little and devolpe an anti-technology personality and insist on making my wife use the out house with me. BUT if i have stumbled on a mass missunderstanding of basic phsyics, the next time you see a lowly grease monkey in conversation with another motorhead. Feel free to but into the conversation and try to expand their conversation beyond the black magic they know as hot rodding into true mechanical engineering aplication.
Love SSVPV8
I am not so smart but consider myself above the average mechanic. However i have come across information from highly respeced racing mechanics that i can't make sense of. I have researched this subject for a while and it seems everyone gets it but me
It involves the rotating assembly(fly wheel, pulley, crankshaft,connecting rods, and pistons) on any piston driven internal compustion engine. They say when you replace the pistons of an engine with a different weight piston you must rebalance the crankshaft by machining it on the counter wieght ends. An example is switching from the low compression pistons in my v-8 to an aftermarket lighter alloy high compression piston designed for high compression. They say the counter weight balance balances the weight of the connecting rod and half of the weight of the piston. They also say the resulting imbalance of not rebalancing the crank would create vibrations that would eat the bearings.
This is where I have the problem, to me it seems the crank shaft counter weight should only balance half the connecting rod weight and none of the piston weight as none of the piston weight is spinning. Further more it seems to me the force of the weight on the crank from the piston travel would pale incomparison to the forces of compresing the air and fuel, the exploding air fuel ratio, the almost free travle of the piston pushing the spent gasses out, and the suction of sucking new air and fuel in.
Now like I said. I'm probably not as smart as most of the forum users as i have no education beyond high school. So if I really am thinking backwards, take this oprotunity to flame me I will take it for wasting you time on such a large post. I may also cry a little and devolpe an anti-technology personality and insist on making my wife use the out house with me. BUT if i have stumbled on a mass missunderstanding of basic phsyics, the next time you see a lowly grease monkey in conversation with another motorhead. Feel free to but into the conversation and try to expand their conversation beyond the black magic they know as hot rodding into true mechanical engineering aplication.
Love SSVPV8