#4 is the front cylinder on the driver's side. I would have assumed bent valves too, had I seen the broken rockers before doing a compression test on the left bank and discovering that the valves in cylinders #5 and #6 seem to be working just fine. And #4's broken exhaust rocker was jammed against the valve spring; now that I've unjammed it and retested #4, the compression's not so bad with the valve fully closed (imagine that). Compression is fine on the right bank, where the belt was only off 1 tooth and there weren't any horrible noises being produced.
I've checked the shop manual and confirmed that the rocker shaft does come out the front of the head, but it looks long enough that the radiator may have to come out. So I'll probably go ahead and try to replace those rockers with spares I have on hand, but if anything beyond that is required I probably just need to accept that this is the end of the road for ZARAA6693C1002419, as it's probably not worth the cost of a headgasket, and any sane person would have scrapped it a couple years ago on account of its structural condition. -Joe At 7:36 AM -0800 2/14/10, Russell Neely wrote: > With the left cam retarded 3 or 4 teeth, I would say he pistons >touched the exhaust valves and broke the rocker arms. I would also >suspect bent valves. > Number 4 is the front cylinder on the passenger side, right? I >think that is the way Alfa numbers the cylinders on the V-6. Chevy >and others number V configuration engines from front to rear >according to the rod journal on the crankshaft. > With the cam only off one tooth, I doubt a valve touched a >piston, but the reduced compression could be a bent valve. Or a >burnt valve. Or bad rings. Or a hole in the piston. Who knows? > > So you probably need to pull the heads. But is the car worth it? >You could replace the rockers and see what you have compression in >all the cylinders. Then see if you want to continue to drive it. >Not sure if you can pull the rockers with the heads in place or not. >Pull the valve cover and look. > >Ciao, >Russ Neely > > > > > >From: Joe Elliott <[email protected]> >To: AD <[email protected]> >Sent: Sat, February 13, 2010 3:55:41 PM >Subject: [alfa] Re: GTV-6 engine problem > >The verdict (short version): All three rocker arms in the left >cylinder head are broken, and cylinder #4 exhibits reduced >compression. > >Can the rocker shaft be removed with the engine in the car? As >reluctant as I am to spent any money on this dangerously rusty, >essentially worthless car, I'd be inclined to replace the broken >rockers and live with the compromised compression if I could fix it >with the engine in the car. > >I'm still puzzled as to why this happened. I couldn't find anything >noticeably wrong with the belt or the tensioner. The ignition was >still timed correctly, the right cam was retarded one tooth, and the >left cam was retarded three or four teeth. What the hell? > >Joe Elliott >'82 GTV-6 >'88 Porsche 928 >'68 Fiat Dino Coupe >-- >to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi >or email "unsubscribe alfa" to ><mailto:[email protected]>[email protected] -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
