YBS1, I really did not want to have to do this but now I guess I must explain the subtleties that make your statement wrong. Sigh...
If you were to MEASURE engine performance then that would hold true. But we are not discussing MEASUREING but rather DEVELOPING torque and horsepower. How can I explain this... ok, if your theorem is correct then an engine spinning at 600rpm will have exactly half the horsepower of an engine spining at 1200rpm and so on. We both know that the development of hp and torque is a curve and not a line. You can mathematically measure hp by Torque*RPM/5252=Horsepower but in the real world if you spin an engine twice as fast you will not get twice the horsepower. Again the difference is measurement where this formula applies, and development where this formula does not apply.
Your theorem that crankshaft stroke length and connecting rod length does not have an effect on torque output of a motor, well it does, because of the mechanical advantage increase or decrease givin by changing stroke distance will directly affect torque. Do yourself a big favor call a local facility in your area that has an engine dyno and ask them that. Ask them "will changeing crankshaft stroke length change torque output?" Better yet, call several facilities and see what they all tell you (it will be the same) If you won't take it from me, then maybe you'll take it from them. Oh by the way a good place to call is AEM (advanced engine management) in anahiem california. They are a large and respected name in engine performance parts manufacturing and tuning, they have a dyno on the facility. Ask them about your theorem that rod length, bore diameter, and stroke length has no direct bearing on torque development.
I use many methods to tailor torque development to match the curve needed. The largest adjustment can be found with modifying crank stroke length and rod length. Smaller adjustments can be made with varying valve timing, lift,duration, and lobe geometry, intake runner length,size, shape,exhaust manifold runner length size, shape. The smallest torque adjustments can be made through ignition timing adjustments, air/fuel ratio adjustments at specific rpms, etc.
I don't know how else to explain to you that you're wrong about these things except to direct you to other engine builders. Maybe with all of us telling you the same thing, maybe you'll accept it then. The largest impact on torque performance you can make is by changing rod length and stroke length.
If everything else is an open adjustment inculding bore size and crank stroke I can make you an engine that develops 300ft-lbs of torque at 2000rpm then change rod length and stroke length on that same engine then develop 350ft-lbs of torque at that same 2000rpm. Heck without changing anything but the cam timing I can give you at least a 10ft-lb +/- adjustment on torque at that same 2000rpm on the same engine.
Just call up some other engine builders and see if your theorems about stroke length being not directly related to torque productions holds up in their experiences.
If you were to MEASURE engine performance then that would hold true. But we are not discussing MEASUREING but rather DEVELOPING torque and horsepower. How can I explain this... ok, if your theorem is correct then an engine spinning at 600rpm will have exactly half the horsepower of an engine spining at 1200rpm and so on. We both know that the development of hp and torque is a curve and not a line. You can mathematically measure hp by Torque*RPM/5252=Horsepower but in the real world if you spin an engine twice as fast you will not get twice the horsepower. Again the difference is measurement where this formula applies, and development where this formula does not apply.
Your theorem that crankshaft stroke length and connecting rod length does not have an effect on torque output of a motor, well it does, because of the mechanical advantage increase or decrease givin by changing stroke distance will directly affect torque. Do yourself a big favor call a local facility in your area that has an engine dyno and ask them that. Ask them "will changeing crankshaft stroke length change torque output?" Better yet, call several facilities and see what they all tell you (it will be the same) If you won't take it from me, then maybe you'll take it from them. Oh by the way a good place to call is AEM (advanced engine management) in anahiem california. They are a large and respected name in engine performance parts manufacturing and tuning, they have a dyno on the facility. Ask them about your theorem that rod length, bore diameter, and stroke length has no direct bearing on torque development.
I use many methods to tailor torque development to match the curve needed. The largest adjustment can be found with modifying crank stroke length and rod length. Smaller adjustments can be made with varying valve timing, lift,duration, and lobe geometry, intake runner length,size, shape,exhaust manifold runner length size, shape. The smallest torque adjustments can be made through ignition timing adjustments, air/fuel ratio adjustments at specific rpms, etc.
I don't know how else to explain to you that you're wrong about these things except to direct you to other engine builders. Maybe with all of us telling you the same thing, maybe you'll accept it then. The largest impact on torque performance you can make is by changing rod length and stroke length.
If everything else is an open adjustment inculding bore size and crank stroke I can make you an engine that develops 300ft-lbs of torque at 2000rpm then change rod length and stroke length on that same engine then develop 350ft-lbs of torque at that same 2000rpm. Heck without changing anything but the cam timing I can give you at least a 10ft-lb +/- adjustment on torque at that same 2000rpm on the same engine.
Just call up some other engine builders and see if your theorems about stroke length being not directly related to torque productions holds up in their experiences.
although it does try to beef up lower end torque by having two different intake runner lengths, the longer runner for increased lower rpm torque then a shorter runner opening up at higher rpm to enhance hp. It would make your blazer feel like it was running on 2 cylinders till it got to 5500rpm. 120hp per liter, it's not hard to match or beat that at all. But to acheive that in a street legal car that meets emisions and still meets dependability standards and is mass produced.... WOW, that's an unmatched feat. A lot of people in that past said it would impossible to do on a mass production level.... I'm glad to see that there are manufacturers out there (honda) that didn't know what impossible meant.
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