Date: 24 Sep 2006 12:56:37 GMT From: Dave Hinz <DaveHinznospaml.com> Subject: Re: Saab 99 engine ticking / engine failure curiosity
On Sun, 24 Sep 2006 12:48:19 +0100, MarkA <nospamnospam.thanks> wrote: > I'll have a go! Looking at the pictures, it would certainly seem that the > tappet failed in some manner and pieces of it were driven through the side > of the cam-carrier by the rotation of the cam lobe..? Is there none of the > tappet at all left in the bore of the cam-carrier? I'm betting there's part of the shell of the cylindrical part still in there. > Having recently rebuilt the head on my '78t, I'm at a bit of a loss to > explain the tappet failure - they are fairly substantial, and not especially > loaded other than the bearing surface between the cam lobe and the shim. Is > it possible that the valve was stuck as part of the engine seizure and when > the engine finally turned it placed a massive loading through the bearing > face of that tappet causing it to crack and ultimately leading to its > catastophic failure??? That's the thing. I'm trying to come up witha credible side-load force scenario. Unless the valve stuck, came lobe made the tappit _tilt_ in the housing, breaking it? Which way does the cam rotate on that when the engine is running? > Better explanations may well become apparent as you strip it further... I wonder if he's got a bent valve.
