glenn120A
Automotive
- Nov 18, 2003
- 2
I think I have read 50% of all the info on the web about valve train geometry as it applies to small block Chevy engines. I've found the following:
Most companies in the manufacturing business promote the right angle at half lift design.
Most agree on the motion of the roller on the valve tip being an arc and traveling across and back across the valve tip.
Jesel puts forth a design concept called low trunion that straightens the arc during the later part of the lift to reduce side loading.
One outfit in texas has the roller centered over the valve tip at half lift.
The new Crane rockers have lowered the push rod seat relative to the roller tip and shaft centerline to cause a ratio change during operation.
Lets just say I think I have a handle on understanding what these guys are selling but what is it that the engine really needs?
Richard maskin told me that the low trunion approach is necessary above .700" of lift.I have always thought it helped reduce the overall guide drag but can't seem to get passed the idea that the roller sliding friction is greater as the footprint increases.
Anyone that can straighten me out on some of these points?
Most companies in the manufacturing business promote the right angle at half lift design.
Most agree on the motion of the roller on the valve tip being an arc and traveling across and back across the valve tip.
Jesel puts forth a design concept called low trunion that straightens the arc during the later part of the lift to reduce side loading.
One outfit in texas has the roller centered over the valve tip at half lift.
The new Crane rockers have lowered the push rod seat relative to the roller tip and shaft centerline to cause a ratio change during operation.
Lets just say I think I have a handle on understanding what these guys are selling but what is it that the engine really needs?
Richard maskin told me that the low trunion approach is necessary above .700" of lift.I have always thought it helped reduce the overall guide drag but can't seem to get passed the idea that the roller sliding friction is greater as the footprint increases.
Anyone that can straighten me out on some of these points?
