Over the last few years my AH 3000 BJ7 has developed noisy tappets. Valve adjustments by 13-1 rule to spec still results in valve train clatter at idle Engine runs smooth, no overheating with 55psi oil pressure at speed and 25 to 30 psi at idle when hot. Just those noisy tappets, particularly for valves #7, 8 and #9 using a stethoscope. Valve cover off shows good oil lubrication throughout valve train. Oil seeping through holes; no geysers. Rockers are good. Dismantled valve assembly, removed pushrods and lifters (tappets). On inspection, the condition of both pushrods and tappets is disconcerting.
Pushrods show ball seat wear with corresponding wear patterns on tappet cups. Some of the tappets cups appear to be worn through or wearing through and have what appears to be pin holes. The cam facing side of the tappets are clean with normal wear pattern for a 50K mile rebuilt engine (trying to upload pics). So, a few questions:
Can tappets and pushrods be renewed without replacing camshaft? And if so, are the usual suppliers suggested for these parts (The worn ones are Moss items from 1990s).
On replacement, should the flat tappet engine break-in procedure be followed? 2000RPM for 20 min.s with ZDDP additives etc.
All suggestions are encouraged and welcomed. Thanks, GONZO
Pushrods show ball seat wear with corresponding wear patterns on tappet cups. Some of the tappets cups appear to be worn through or wearing through and have what appears to be pin holes. The cam facing side of the tappets are clean with normal wear pattern for a 50K mile rebuilt engine (trying to upload pics). So, a few questions:
Can tappets and pushrods be renewed without replacing camshaft? And if so, are the usual suppliers suggested for these parts (The worn ones are Moss items from 1990s).
On replacement, should the flat tappet engine break-in procedure be followed? 2000RPM for 20 min.s with ZDDP additives etc.
All suggestions are encouraged and welcomed. Thanks, GONZO