both you and Joe are wrong technicallySchmidtMotorWorks wrote: ↑Thu Aug 02, 2018 2:54 pm Are you claiming that on a non-dwell cam, that acceleration is zero at max lift?
If so, you are confused.
1)
here is a 2nd order polynomial defining one such lift function over the nose. i've done the derivatives using mathematical theory. I've not done it by a numerical approximation so the numbers are EXACT. the exact function is plotted in the title.
as you can see to left of peak lift the velocity is positive then goes to zero then continues to negative.
due to being a 2nd order polynomial the acceleration comes out constant negative
it is also plain to see that velocity is zero at peak lift but acceleration is not
this proves Joe wrong.
2)
here is a 4th order polynomial defining another such lift function over the nose. i've done the derivatives using mathematical theory. I've not done it by a numerical approximation so the numbers are EXACT. the exact function is plotted in the title.
as you can see being a 4th order polynomial the velocity comes out to 3rd order polynomial and acceleration a 2nd order meaning both velocity and acceleration ARE zero at peak lift
Obviously this is a VERY simplified polynomial example as is the first as the lift curve function, but it proves it IS possible to have zero acceleration at peak lift mathematically without "any" dwell. if you were to define something more realistic there would be combinations of different orders with a general function maybe similar to
e.g -Ax^4 + Bx^3 - cx^2 + Dx - E
giving a different result