Hyd Roller vs Hyd Flat tappet on SM heads
Slow down, your arguing with someone who isn't arguing with you.
I'm just pointing out a potential issue with the drawing. Do you want your point to be based on correct, or incorrect info?
Carry on...
I wasn’t arguing. It’s pointing out how much too wide an .080 sweep really is.
I apologize because I thought it was you who posted that wide sweep.
It was Cookietruck. It doesn’t really matter who it is.
It matters that people who come along later and read these threads get the correct information and not a bunch of bullshit like you see in this thread.
Guys run their stuff that wide and get away with it. You also see failed rockets long before their service life is up, and the aluminum rocket gets the blame when it’s really a geometry issue.
It’s also crazy to see how unstable the valve train is when the geometry issue off.
Plus the performance loss from bad geometry and the valve moving off the seat very slow and speeding up around the nose, when in fact you want the valve moving off the seat as fast as can be done reliably and have the valve slow down around the nose.
If the valve is slow off the seat and fast over the nose, you have the valve spending more time where curtain area is small and flow is limited, and then when the valve is near max lift it’s moving too fast where you have the most flow. That’s backwards.
You want the valve to move slowly around max lift where head flow is the highest.
So there are several issues getting corrected with geometry.