onan expert needed

[Dale 0]

I took my p220 with 860hr to a machine shop to get a valve seat installed and a valve job. they called me today and said i need all new valves because the stems were worn and the lash cap was touching the keepers. I went to take a look and the inside of the cap and stem ends look new. when I looked inside the cap it looks like the stem never touched the back of the cap the outside is poloshed up there the cap is rubbing the keepers. I looked in a onan shop manual they refer to the caps as valve rotaters and the valves should rotate freely so my questions is should the cap push on the keepers if they are not I am 100% sure it's not from wear and must have the wrong parts. the valves/caps are the same which is hard to belive they all wore the same hope i make sence thanks dale

[300zx 7]

Dale, it is interesting. I don't have a lot of experience, but the last Onan I tore down to grind the valves and resurface the seats, I had trouble getting the keepers back in. I thought it was because the gap between the cap and tappet had closed up (due to grinding the valves) and I just adjusted the tappet back so the cap slid down enough to let the keeper seat. I just can't imagine that much wear between the cap and the end of the valve, but, quite honestly I had never thought about it. I put this engine back together and it ran fine. I'll be curious what other have to say.

[300zx 7]

Dale, I just took down another P220 Onan. I couldn't remove the keepers without making sure there was clearance between the tappet and cap. This engine only has 128 hours on the hour meter. (I say that cautiously, because if the oil pressure switch isn't working, the hours don't register) So, I wouldn't think the keepers should interfere with the caps, but on two of the engines I have checked, they did and this last one had little wear. You could still see cross hatching in the cylinder walls.