Question about a ELC and effects on EVO
#1
Question about a ELC and effects on EVO
Given a static ILC, widening the LSA and increasing advance for ILC opens the Exhaust valve sooner?
Ex.
224/224 112+2
ivo - 2 btdc
ivc - 42 adtc
evo - 46 bbdc
evc - 2 btdc (or -2 atdc)
overlap - 0
224/224 114+4
ivo - 2 btdc
ivc - 42 atdc
evo - 50 bbdc
evc - 6 bbdc (or -6 atdc)
overlap - -4
also
224/224 114+2
ivo- 0 btdc
ivc - 44 atdc
evo - 48 bbdc
evc - 4 bbdc (or -4 atdc)
overlap - -4
I guess what I'm struggling to understand is why if the lobes are farther apart, the events are happening closer together? or in opposite fashion. It would seem to me that spacing the exhaust lobe farther away would delay the exhaust valve events, not speed them up?
as the ECL increases, the EVO occurs sooner? why? that would mean a cam with a tight LCA not only has a later EVO for low end torque? but also has more overlap for better high RPM power? I know a cam can't have both.. which is why this is not making sense to me.
Ex.
224/224 112+2
ivo - 2 btdc
ivc - 42 adtc
evo - 46 bbdc
evc - 2 btdc (or -2 atdc)
overlap - 0
224/224 114+4
ivo - 2 btdc
ivc - 42 atdc
evo - 50 bbdc
evc - 6 bbdc (or -6 atdc)
overlap - -4
also
224/224 114+2
ivo- 0 btdc
ivc - 44 atdc
evo - 48 bbdc
evc - 4 bbdc (or -4 atdc)
overlap - -4
I guess what I'm struggling to understand is why if the lobes are farther apart, the events are happening closer together? or in opposite fashion. It would seem to me that spacing the exhaust lobe farther away would delay the exhaust valve events, not speed them up?
as the ECL increases, the EVO occurs sooner? why? that would mean a cam with a tight LCA not only has a later EVO for low end torque? but also has more overlap for better high RPM power? I know a cam can't have both.. which is why this is not making sense to me.
Last edited by Paint_It_Black; 09-03-2007 at 04:36 PM.