[guudasitgets]

The theory of the valves being damaged comes from the test that was made after an engine was run without any exhaust, then allowed to cool and taken apart. It was found that as cold air hit the hot valve it warpped the valve haveing cold air hitting it from one side. Top Feulers have individual runners because of the great mass of gasses that have to be expelled as well as the tuning is for a specific RPM. They can't have a collector system, theres too much heat that would back up into the engine. The fire you see coming out of the exhaust is actually hydrogen igniting as it hits the atmosphere. I Learned this when I worked on The Past Blue Ribbon Charger NHRA Top Fuel Funny Car in the seventies, not a bad part time job for an 18 year old kid.