Interesting...I doubt 20/50 oil caused it,as mentioned,thousands of drag racers use it.
Those roller lifters appear to have either got sideways or the engine was reved beyond the cam design.The roller pins coming loose is a sign of extreme abuse.
The rollers will get sideways if the cam allows the lifter to rise above or below the forked retainer.Those little wheels on the lifters don't work worth a [censored] running sideways.
Over running the cam or "Valve float" with a roller cam can be fatal to the valve train,and that's what it looks like.
Hi volume pumps can often cause problems by overloading the distributor and cam gear.
Those roller lifters appear to have either got sideways or the engine was reved beyond the cam design.The roller pins coming loose is a sign of extreme abuse.
The rollers will get sideways if the cam allows the lifter to rise above or below the forked retainer.Those little wheels on the lifters don't work worth a [censored] running sideways.
Over running the cam or "Valve float" with a roller cam can be fatal to the valve train,and that's what it looks like.
Hi volume pumps can often cause problems by overloading the distributor and cam gear.