Did you use brand new lifter? Any chance the valves were adjusted when the lifters had no oil? This could cause the lifters to open the valves too far.
Type: Posts; User: 1project2many
Did you use brand new lifter? Any chance the valves were adjusted when the lifters had no oil? This could cause the lifters to open the valves too far.
I would not expect the tune is the problem. Valves can go this quickly with valve <-> piston collisions, valve guides too tight, or when high compression meets wrong octane fuel. If you're not...