This engine was rebuilt using Holley Systemax components about 3000 miles ago. I removed the engine from my friends Jeep (was running well), externally refreshed it, and installed it in my Jeep. So there is a history of it running good with no problems. Same internal, dist, carb. Only changes were re-setting timing, new fuel lines, valve covers.

Initial startup of a few minutes had misconnected vacuum lines, and timing was off. Ever since then (10 minutes total run time until now), the engine runs very poor with excessive valvetrain noise, and coolant leaking excessively into cylinder number 8. Upon disassembly, I found a head gasket failure in the 4 corner cylinder outer walls (see picture closeup). I also found 3 rocker arms with flattened roller tips. No other damage was found to the pushrods, hydraulic lifters, valves, springs, heads, or piston heads.

Felpro says this kind of head gasket failure is caused by excessively high combustion chamber temps (detonation, lean, etc).

The damaged rocker arm roller tips are at valve 1Exhaust, 5Exhaust, and 7Intake. Maybe the flat spot was over time, and not one incident? It has also been suggested a lack of proper lubrication cause failure (oil press never seemed unusual). I want to prent this from happening again on new components. If I just had the timing too far off and that did it, ok. If it is something mechanical, I want to solve it and not ruin more parts or the whole engine.

I have replaced head gaskets and rocker arms. I want opinions from anyone who has ideas of what might have caused this so I don’t just put it together and have the problem occur again. Has anyone seen this kind of failure before? Any ideas of other damage I may not have found that exists? Guesses, questions, and ideas are welcome. Thanks.

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