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RPM Danger zone?
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,201
Likes: 3,089
From: NW AR
Valve float is when the lifters are pumped up and are holding the valves open some when they are supposed to be closed. That's why solid lifters are needed for higher RPM's. When the valves are open a bit, you ain't gonna make any power and the motor won't spin any faster. The valve would have to be kinda stuck open to cause damage from a piston hit, not just float a little open. Recall that my valve was stuck open when the valve guide dropped out of the head on me one year and I still ran it 60 miles like that without the valve colliding with the piston. The valve only has to be open a little bit to lose all power and has to be open a lot to collide with the piston on a relatively stock motor.
But, 6K or 6.5K is a good place, if you want to set it somewhere. Or set it at 3500 and feel "really, really safe."
But, 6K or 6.5K is a good place, if you want to set it somewhere. Or set it at 3500 and feel "really, really safe."
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,201
Likes: 3,089
From: NW AR
Valve float is when the lifters are pumped up and are holding the valves open some when they are supposed to be closed. That's why solid lifters are needed for higher RPM's. When the valves are open a bit, you ain't gonna make any power and the motor won't spin any faster. The valve would have to be kinda stuck open to cause damage from a piston hit, not just float a little open. Recall that my valve was stuck open when the valve guide dropped out of the head on me one year and I still ran it 60 miles like that without the valve colliding with the piston. The valve only has to be open a little bit to lose all power and has to be open a lot to collide with the piston on a relatively stock motor.
But, 6K or 6.5K is a good place, if you want to set it somewhere. Or set it at 3500 and feel "really, really safe."
But, 6K or 6.5K is a good place, if you want to set it somewhere. Or set it at 3500 and feel "really, really safe."
Elite HDF Member
Joined: Oct 2005
Posts: 3,872
Likes: 83
From: Canton, Michigan
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